Re: [EVDL] Range vs Speed
Tire pressure is an important consideration. I have a theory that says that the tire pressure should be slightly less than the pressure that it takes to deform the surface the tire is rolling over since it takes more energy to deform most surfaces than to deform the tire. Some think that by increasing tire pressure that I reduce traction due to less surface area on the road. Well, in some situation maybe yes, but no. The coefficient of friction between two give materials is a constant. In a low tire pressure situation there is greater surface area in contact with the road at a lower pressure. In a high tire pressure situation there is less surface area in contact with the road but at a higher pressure. I've not done that analysis but I believe that the amount of force it takes to break traction is basically the same for both situations. I run 115 psi in my road bike tires, 43 psi in my car tires, 7psi in my electric ATV tires, 25 to 45 psi in my mountain bike tires and 4 to 15 psi in my fatbike tires. My theory seems to hold true when riding the road bike from asphalt to the lawn compared to doing the same on the fatbike. Oh, and both have great traction in both environments. Even when backpacking with my hard soled hiking shoes, walking on the harder part of the trail takes less effort than walking on the soft part of the trail. On Nov 11, 2014, at 4:07 PM, via EV ev@lists.evdl.org wrote: Send EV mailing list submissions to ev@lists.evdl.org To subscribe or unsubscribe via the World Wide Web, visit http://lists.evdl.org/listinfo.cgi/ev-evdl.org or, via email, send a message with subject or body 'help' to ev-requ...@lists.evdl.org You can reach the person managing the list at ev-ow...@lists.evdl.org When replying, please edit your Subject line so it is more specific than Re: Contents of EV digest... Also, please be careful not to append the entire digest to your reply. Many mail systems do this by default. Trim or delete the digest text from the bottom of your message, and quote only the parts to which you're replying. Today's Topics: 1. Re: Range vs Speed (Michael Ross via EV) 2. Re: Range vs Speed (Cor van de Water via EV) 3. Re: New EV trike pickup. (jerry freedomev via EV) 4. Battery future vid very good (jerry freedomev via EV) 5. EVLN and other posts ... (brucedp via EV) -- Message: 1 Date: Mon, 10 Nov 2014 16:48:21 -0500 From: Michael Ross via EV ev@lists.evdl.org To: Lee Hart leeah...@earthlink.net,Electric Vehicle Discussion List ev@lists.evdl.org Subject: Re: [EVDL] Range vs Speed Message-ID: cannqeo+qtbmtvdqce2qb8uc9fz--ewyb5j0t9k-kzwf7oon...@mail.gmail.com Content-Type: text/plain; charset=utf-8 On a road bike (more efficient than thick tired MTB) bicycle tires are very thin. There is some heat generated in the rubber itself from weighting and de-weighting and side loads. The molecules are literally sliding across each other, unwinding and winding back up. Heat results. The fabric carcass also has some flexing and sliding around. Heat results. Because the bike is human powered weight is measured out in grams instead of kilos or pounds. In particular the rotating bits have inertia to overcome spinning up - light tires make the bike noticeable more responsive. Pumping the tires up hard reduces the flexing and decreases rolling resistance. But designing them with less thickness is always better for efficiency. Harder compounds where there is less internal flow helps too. If you could run a tire 1/8 inch thick you would get much better efficiency from it. On Mon, Nov 10, 2014 at 1:56 PM, Lee Hart via EV ev@lists.evdl.org wrote: jerry freedomev via EV wrote: Hi Lee and All, I'm using some early Mazda Miata front hubs, brakes that has retraction V shaped springs that with just a couple tiny holes drilled in the pad for the wire spring end to fit, could fit many disc brakes that don't have them stock. Likely able to do it with just removing the tire. That's a great idea. I'll have to look into that. My LeCar EV always has dragging brakes. Like many, they depend on the roll-back of the rubber piston seals as their spring to pull back just a tiny bit. Then the calipers are supposed to be floating on pins, so that the slight runout of the rotor and play in the wheel bearing are enough to push the pads away from the rotor. It doesn't work. The o-ring pullback is too little, the pad is just loose between the piston and rotor (and tends to lay against the spinning rotor), and the floating pins always rust up and won't move. On Tire LRR common car tires are bad but MC tires are 2x's worse I found on my Streamliner MC low CG chassis !! I'll have to find better before doing the EV Streamliner, maybe even adapting LRR car tires if I can't
Re: [EVDL] Range vs Speed
Klaus, I am sorry you are wrong. It is pretty clear if you drive hard on over inflated tires that you have far less traction. In an emergency - such as when raining you will slide and hydroplane more easily. There is not a constant, or linear function between pressure on the road and control. Under normal rolling there is no motion at all of the tire on the pavement - except the rubber squirms around on the road as the rubber is pressed and lifted from the road - it is a situation of static friction. If you have less material in contact, then side loads overcome the static conditions and kinetic friction reigns which is at least an order of magnitude less. When a tire is sliding it is a very dynamic situation with the tire rippling and gripping and releasing, in a complex and changing manner. You can regain control ONLY because static friction is reasserted. Because there is such a difference in between static and kinetic friction the transition can be violent. A good handling car tire, holds the tread on the road so that it can exist in a dynamic function where some of the contact patch is slipping and some is static. The squealing you hear is the sound of this - some of the tire is always gripping - some is slipping when in the boundary condition. You can seriously mess this up by inflating improperly. Highest efficiency is always at odds with safety and controlled handling during spirited driving or emergencies. One primary detriment to control is the tire being very tight and inflexible - over inflated. There is a lower limit also where the rim is holding a tire whose structure is no longer stable - it is wrinkling and hopping instead of the tire staying flat (deformed properly) as designed to do. Mike On Tue, Nov 11, 2014 at 5:56 PM, Klaus via EV ev@lists.evdl.org wrote: Tire pressure is an important consideration. I have a theory that says that the tire pressure should be slightly less than the pressure that it takes to deform the surface the tire is rolling over since it takes more energy to deform most surfaces than to deform the tire. Some think that by increasing tire pressure that I reduce traction due to less surface area on the road. Well, in some situation maybe yes, but no. The coefficient of friction between two give materials is a constant. In a low tire pressure situation there is greater surface area in contact with the road at a lower pressure. In a high tire pressure situation there is less surface area in contact with the road but at a higher pressure. I've not done that analysis but I believe that the amount of force it takes to break traction is basically the same for both situations. I run 115 psi in my road bike tires, 43 psi in my car tires, 7psi in my electric ATV tires, 25 to 45 psi in my mountain bike tires and 4 to 15 psi in my fatbike tires. My theory seems to hold true when riding the road bike from asphalt to the lawn compared to doing the same on the fatbike. Oh, and both have great traction in both environments. Even when backpacking with my hard soled hiking shoes, walking on the harder part of the trail takes less effort than walking on the soft part of the trail. -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/2014/da4a2f56/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
John Lussmyer via EV wrote: My problem is finding a LRR tire that fits a Ford F-250 truck... Interestingly enough, I've read that they *do* make low rolling resistance tires for heavy trucks. Fuel economy matters a lot to long-haul truckers! Now, how low their LRR tires are, I don't know. Normal car tires range from 0.006 to 0.015 rolling resistance. That's the ratio of the force needed to roll it divided by the load on the tire. I.e. a tire with a 0.01 RR means it takes 1 lb force to push for every 100 pounds of vehicle weight. -- A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away. -- Antoine de Saint Exupery -- Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
Nothing voodoo about it. Minimizing energy use and maximizing percent energy regained with regen are two different things. I said you get more energy back into the pack stopping faster with regen. Of course net energy use increases with more stops/starts, but percentage energy regained with regen increases. Similarly, higher constant speed between start/stops also increases net energy use but it also increases energy regained with regen. So, if you are looking for where you would get the greatest difference in energy used with regen versus without, it would be a driving pattern that has many start/stops with higher speeds in between. The calculations describe my car's performance quite well. -- View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Range-vs-Speed-tp4672366p4672520.html Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
LRR is code for labeled for high pressure. No 35 psi tire is LRR. Load range E truck tires (80 psi) in a highway tread are almost all rated as LRR. So I am confused when you say you can't find a LRR tire for your truck? And yes, I have personally run 44 psi car tires at 75 psi for their entire life with no problems even on rocky Montana back roads. That was the only way to get over 30 mpg with awd 96 Subaru. As for my truck and trailer I keep them right at 80 psi though I am confident they can safely handle much more. On my 36 International hot rod I will likely be testing big truck tires on 17.5 rims. These are real truck tires and come in load range G at 120 psi! There is a weight penalty for stop and start, but just cruising I predict better efficiency than car tires. On Nov 10, 2014 8:02 AM, tomw via EV ev@lists.evdl.org wrote: Nothing voodoo about it. Minimizing energy use and maximizing percent energy regained with regen are two different things. I said you get more energy back into the pack stopping faster with regen. Of course net energy use increases with more stops/starts, but percentage energy regained with regen increases. Similarly, higher constant speed between start/stops also increases net energy use but it also increases energy regained with regen. So, if you are looking for where you would get the greatest difference in energy used with regen versus without, it would be a driving pattern that has many start/stops with higher speeds in between. The calculations describe my car's performance quite well. -- View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Range-vs-Speed-tp4672366p4672520.html Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141110/5a9ba8a6/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
As for losing 10 mpg by switching to different LRR tires, I bet $50 they had the pressure at 32psi front, 28 psi back. That is only way to lose 10 mpg. Two different LRR tires might be 1-3 mpg different, not 10 mpg! On Nov 10, 2014 8:27 AM, Marcus Reddish marcus.redd...@gmail.com wrote: LRR is code for labeled for high pressure. No 35 psi tire is LRR. Load range E truck tires (80 psi) in a highway tread are almost all rated as LRR. So I am confused when you say you can't find a LRR tire for your truck? And yes, I have personally run 44 psi car tires at 75 psi for their entire life with no problems even on rocky Montana back roads. That was the only way to get over 30 mpg with awd 96 Subaru. As for my truck and trailer I keep them right at 80 psi though I am confident they can safely handle much more. On my 36 International hot rod I will likely be testing big truck tires on 17.5 rims. These are real truck tires and come in load range G at 120 psi! There is a weight penalty for stop and start, but just cruising I predict better efficiency than car tires. On Nov 10, 2014 8:02 AM, tomw via EV ev@lists.evdl.org wrote: Nothing voodoo about it. Minimizing energy use and maximizing percent energy regained with regen are two different things. I said you get more energy back into the pack stopping faster with regen. Of course net energy use increases with more stops/starts, but percentage energy regained with regen increases. Similarly, higher constant speed between start/stops also increases net energy use but it also increases energy regained with regen. So, if you are looking for where you would get the greatest difference in energy used with regen versus without, it would be a driving pattern that has many start/stops with higher speeds in between. The calculations describe my car's performance quite well. -- View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Range-vs-Speed-tp4672366p4672520.html Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141110/92a66e75/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
You lose.. it looks like you owe me $50... you can paypal me at e...@tucson.com This has been substantiated by many Insight owners on the Insightcentral.net list. None of the other LRR tires work as well as the Potenza RE 92's on the Insight. Rush www.TucsonEV.com -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Marcus Reddish via EV Sent: Monday, November 10, 2014 8:51 AM To: tomw; Electric Vehicle Discussion List Subject: Re: [EVDL] Range vs Speed As for losing 10 mpg by switching to different LRR tires, I bet $50 they had the pressure at 32psi front, 28 psi back. That is only way to lose 10 mpg. Two different LRR tires might be 1-3 mpg different, not 10 mpg! On Nov 10, 2014 8:27 AM, Marcus Reddish marcus.redd...@gmail.com wrote: LRR is code for labeled for high pressure. No 35 psi tire is LRR. Load range E truck tires (80 psi) in a highway tread are almost all rated as LRR. So I am confused when you say you can't find a LRR tire for your truck? And yes, I have personally run 44 psi car tires at 75 psi for their entire life with no problems even on rocky Montana back roads. That was the only way to get over 30 mpg with awd 96 Subaru. As for my truck and trailer I keep them right at 80 psi though I am confident they can safely handle much more. On my 36 International hot rod I will likely be testing big truck tires on 17.5 rims. These are real truck tires and come in load range G at 120 psi! There is a weight penalty for stop and start, but just cruising I predict better efficiency than car tires. On Nov 10, 2014 8:02 AM, tomw via EV ev@lists.evdl.org wrote: Nothing voodoo about it. Minimizing energy use and maximizing percent energy regained with regen are two different things. I said you get more energy back into the pack stopping faster with regen. Of course net energy use increases with more stops/starts, but percentage energy regained with regen increases. Similarly, higher constant speed between start/stops also increases net energy use but it also increases energy regained with regen. So, if you are looking for where you would get the greatest difference in energy used with regen versus without, it would be a driving pattern that has many start/stops with higher speeds in between. The calculations describe my car's performance quite well. -- View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Range-vs -Speed-tp4672366p4672520.html Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev- evdl.org/attachments/20141110/92a66e75/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
Marcus Reddish via EV wrote: As for losing 10 mpg by switching to different LRR tires, I bet $50 they had the pressure at 32psi front, 28 psi back. That is only way to lose 10 mpg. Two different LRR tires might be 1-3 mpg different, not 10 mpg! Part of the problem is that LRR is too often just marketing doubletalk -- it doesn't mean anything. Tire companies know what the rolling resistance is; but they certainly don't want consumers to get their hands on the data. They might base their purchases on (gasp! choke!) objective facts rather than advertising, appearance, and price! :-O The automakers really *do* care about LRR, because it helps them meet government mandated fuel economy standards and sell cars. They test tires themselves, and demand performance from the tire companies. As a result, the tire on a new car has better rolling resistance than the same (apparently) identical tire from a tire store. You can tell if they are different by the DOT code on the tire, which identifies who and where it was actually made. You are absolutely correct that many car service people routinely underinflate tires, and often blindly use 32psi no matter what the vehicle calls for. On a 10mpg difference due to tires: That can easily happen with a high-mpg vehicle like the Insight. A 10 mpg drop (from 60mpg to 50mpg) is a 17% drop. The same 17% drop on a 15 mpg vehicle would only reduce it by 2.5 mpg (to 12.5 mpg). PS: Interesting info on the truck tires. Thanks! :-) -- A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away. -- Antoine de Saint Exupery -- Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
jerry freedomev via EV wrote: Hi Lee and All, I'm using some early Mazda Miata front hubs, brakes that has retraction V shaped springs that with just a couple tiny holes drilled in the pad for the wire spring end to fit, could fit many disc brakes that don't have them stock. Likely able to do it with just removing the tire. That's a great idea. I'll have to look into that. My LeCar EV always has dragging brakes. Like many, they depend on the roll-back of the rubber piston seals as their spring to pull back just a tiny bit. Then the calipers are supposed to be floating on pins, so that the slight runout of the rotor and play in the wheel bearing are enough to push the pads away from the rotor. It doesn't work. The o-ring pullback is too little, the pad is just loose between the piston and rotor (and tends to lay against the spinning rotor), and the floating pins always rust up and won't move. On Tire LRR common car tires are bad but MC tires are 2x's worse I found on my Streamliner MC low CG chassis !! I'll have to find better before doing the EV Streamliner, maybe even adapting LRR car tires if I can't find a LRR MC tire. I wonder why motorcycle tires are so much worse. Bicycle tires are obviously very good. What is different about motorcycle tires. Is there some fundamental reason for the higher rolling resistance, or is it just that the manufacturers don't bother (and customers don't care)? -- A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away. -- Antoine de Saint Exupery -- Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
I am guessing that most MC riders are interested in performance and in particular, stick-to-the-road performance, because unlike a car, any loss of traction on a bike will usually crash you (and there are no airbags). My suggestion would be to look at what other (production) EV bikes have done to get good range, Zero Motorcycles comes to mind. Cor van de Water Chief Scientist Proxim Wireless Corporation http://www.proxim.com Email: cwa...@proxim.com Private: http://www.cvandewater.info Skype: cor_van_de_water Tel: +1 408 383 7626 -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Lee Hart via EV Sent: Monday, November 10, 2014 10:56 AM To: jerry freedomev; Electric Vehicle Discussion List Subject: Re: [EVDL] Range vs Speed jerry freedomev via EV wrote: Hi Lee and All, I'm using some early Mazda Miata front hubs, brakes that has retraction V shaped springs that with just a couple tiny holes drilled in the pad for the wire spring end to fit, could fit many disc brakes that don't have them stock. Likely able to do it with just removing the tire. That's a great idea. I'll have to look into that. My LeCar EV always has dragging brakes. Like many, they depend on the roll-back of the rubber piston seals as their spring to pull back just a tiny bit. Then the calipers are supposed to be floating on pins, so that the slight runout of the rotor and play in the wheel bearing are enough to push the pads away from the rotor. It doesn't work. The o-ring pullback is too little, the pad is just loose between the piston and rotor (and tends to lay against the spinning rotor), and the floating pins always rust up and won't move. On Tire LRR common car tires are bad but MC tires are 2x's worse I found on my Streamliner MC low CG chassis !! I'll have to find better before doing the EV Streamliner, maybe even adapting LRR car tires if I can't find a LRR MC tire. I wonder why motorcycle tires are so much worse. Bicycle tires are obviously very good. What is different about motorcycle tires. Is there some fundamental reason for the higher rolling resistance, or is it just that the manufacturers don't bother (and customers don't care)? -- A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away. -- Antoine de Saint Exupery -- Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
I wonder why motorcycle tires are so much worse. Bicycle tires are obviously very good. What is different about motorcycle tires. Is there some fundamental reason for the higher rolling resistance, or is it just that the manufacturers don't bother (and customers don't care)? Not 100% sure, but I think rolling resistance is mostly caused by the tire deforming as it contacts the ground.The lowest rolling resistance would be a solid steel wheel.Any rubber, inflated wheel will deform and have a flat contact spot where it contacts the ground. If this deformation results in heat and this heat is lost to the environment , then you lose the energy and it appears as rolling resistance The area of this flat spot is related to the air presure. It's also related to the sidewall strength.The energy used in this deformation is also related to the shape of this contact patch. I've heard that a wide tire can have lower rolling resistance than a small skinny tire, because if a wide tire's contact patch is the same area as a skinny tire but this makes the flat spot of the wide tire result in less overall deformation. (i.e. it doesn't look so flat from the side and more like a circle instead of a circle with a flat spot) Of course a wide tire will probably have more air resistance though. If the energy used in this deformation could be recovered, then it wouldn't matter -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141110/bcfc0c0a/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
On a road bike (more efficient than thick tired MTB) bicycle tires are very thin. There is some heat generated in the rubber itself from weighting and de-weighting and side loads. The molecules are literally sliding across each other, unwinding and winding back up. Heat results. The fabric carcass also has some flexing and sliding around. Heat results. Because the bike is human powered weight is measured out in grams instead of kilos or pounds. In particular the rotating bits have inertia to overcome spinning up - light tires make the bike noticeable more responsive. Pumping the tires up hard reduces the flexing and decreases rolling resistance. But designing them with less thickness is always better for efficiency. Harder compounds where there is less internal flow helps too. If you could run a tire 1/8 inch thick you would get much better efficiency from it. On Mon, Nov 10, 2014 at 1:56 PM, Lee Hart via EV ev@lists.evdl.org wrote: jerry freedomev via EV wrote: Hi Lee and All, I'm using some early Mazda Miata front hubs, brakes that has retraction V shaped springs that with just a couple tiny holes drilled in the pad for the wire spring end to fit, could fit many disc brakes that don't have them stock. Likely able to do it with just removing the tire. That's a great idea. I'll have to look into that. My LeCar EV always has dragging brakes. Like many, they depend on the roll-back of the rubber piston seals as their spring to pull back just a tiny bit. Then the calipers are supposed to be floating on pins, so that the slight runout of the rotor and play in the wheel bearing are enough to push the pads away from the rotor. It doesn't work. The o-ring pullback is too little, the pad is just loose between the piston and rotor (and tends to lay against the spinning rotor), and the floating pins always rust up and won't move. On Tire LRR common car tires are bad but MC tires are 2x's worse I found on my Streamliner MC low CG chassis !! I'll have to find better before doing the EV Streamliner, maybe even adapting LRR car tires if I can't find a LRR MC tire. I wonder why motorcycle tires are so much worse. Bicycle tires are obviously very good. What is different about motorcycle tires. Is there some fundamental reason for the higher rolling resistance, or is it just that the manufacturers don't bother (and customers don't care)? -- A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away. -- Antoine de Saint Exupery -- Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/ group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141110/88d18b9b/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
That is why *everyone* is always disappointed after installing new tires, whether they are LRR or not - the MPG will *always* go down, even if the spec'ed rolling resistance of the new tires is lower than the previous tires. Because by the time that the tires are worn they are so much thinner and stiffer that the actual losses are lower than the newer (thicker, more flexible) tires. I noticed the same when replacing my 2002 Prius OE tires with the also LRR Sumitomo HTR 200 tires - even while I always pump them to 45+ PSI, the MPG went down considerably (several MPG) from around 50 to around 47 and only after they started to age did the MPG go back up again. (What also helps is that a worn tire is *smaller* so the miles are indicating high, leading to a larger error in artificially increasing MPG, so the only real measurement is in the pump data which I unfortunately do not have). Also, the torque to accelerate the car will reduce a little bit with smaller tires, but this is unlikely to have a significant impact. Cor van de Water Chief Scientist Proxim Wireless Corporation http://www.proxim.com Email: cwa...@proxim.com Private: http://www.cvandewater.info Skype: cor_van_de_water Tel: +1 408 383 7626 -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Michael Ross via EV Sent: Monday, November 10, 2014 1:48 PM To: Lee Hart; Electric Vehicle Discussion List Subject: Re: [EVDL] Range vs Speed On a road bike (more efficient than thick tired MTB) bicycle tires are very thin. There is some heat generated in the rubber itself from weighting and de-weighting and side loads. The molecules are literally sliding across each other, unwinding and winding back up. Heat results. The fabric carcass also has some flexing and sliding around. Heat results. Because the bike is human powered weight is measured out in grams instead of kilos or pounds. In particular the rotating bits have inertia to overcome spinning up - light tires make the bike noticeable more responsive. Pumping the tires up hard reduces the flexing and decreases rolling resistance. But designing them with less thickness is always better for efficiency. Harder compounds where there is less internal flow helps too. If you could run a tire 1/8 inch thick you would get much better efficiency from it. On Mon, Nov 10, 2014 at 1:56 PM, Lee Hart via EV ev@lists.evdl.org wrote: jerry freedomev via EV wrote: Hi Lee and All, I'm using some early Mazda Miata front hubs, brakes that has retraction V shaped springs that with just a couple tiny holes drilled in the pad for the wire spring end to fit, could fit many disc brakes that don't have them stock. Likely able to do it with just removing the tire. That's a great idea. I'll have to look into that. My LeCar EV always has dragging brakes. Like many, they depend on the roll-back of the rubber piston seals as their spring to pull back just a tiny bit. Then the calipers are supposed to be floating on pins, so that the slight runout of the rotor and play in the wheel bearing are enough to push the pads away from the rotor. It doesn't work. The o-ring pullback is too little, the pad is just loose between the piston and rotor (and tends to lay against the spinning rotor), and the floating pins always rust up and won't move. On Tire LRR common car tires are bad but MC tires are 2x's worse I found on my Streamliner MC low CG chassis !! I'll have to find better before doing the EV Streamliner, maybe even adapting LRR car tires if I can't find a LRR MC tire. I wonder why motorcycle tires are so much worse. Bicycle tires are obviously very good. What is different about motorcycle tires. Is there some fundamental reason for the higher rolling resistance, or is it just that the manufacturers don't bother (and customers don't care)? -- A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away. -- Antoine de Saint Exupery -- Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/ group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com michael.e.r...@gmail.com
Re: [EVDL] Range vs Speed
This analysis is missing something when it implies that more and more energy is recoverd when more and more stops are made along the same 10 miles. This is voodoo economics. Yes, the perecentages of energy recovered go up but there is no mention of how drastically the total energy goes up with the more and more stops. I could drive with one foot on regen and one on the acceperator continuously and maybe force 30% recovered energy, but at a huge overall loss. Bob -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Al via EV Sent: Saturday, November 08, 2014 11:02 PM To: tomw; Electric Vehicle Discussion List Subject: Re: [EVDL] Range vs Speed Nice explaination Tom. Al - Original Message - From: tomw via EV ev@lists.evdl.org To: ev@lists.evdl.org Sent: Saturday, November 08, 2014 10:36 AM Subject: Re: [EVDL] Range vs Speed I looked at the effect of acceleration and deceleration rates on energy used per acceleration-deceleration cycle a while back. To simplify the calculation I assumed the same rate for acceleration and deceleration. You do get more energy into the pack stopping faster with regen. For example, at a faster deceleration rate, 6 mph/sec, 7.7% of the vehicle K.E. is lost to work against drag and rolling resistance forces, and at a slower deceleration rate, 2 mph/sec, 23.1% is lost. If you assume a combined motor/controller loss of 20% and drive train loss of 10%, then for the faster deceleration rate 100 – (20 + 10 + 7.7) = 62% of vehicle kinetic energy goes into the battery pack, and at the slower deceleration rate 100 – (20 + 10 + 23.1) = 47% goes into the battery pack. However, you don't get a lot of difference in energy into the pack as a percentage of total energy used when considering a trip with travel at constant speed and a number of acceleration-deceleration cycles. For Example: (1) My car accelerates at 6 mph/sec to 60 mph, drives 10 miles, then decelerates at the same rate to a stop, estimated percent of total energy used that is regained with regen is: 2.7% (2) Acceleration at 6 mph/sec to 35 mph and deceleration at same rate 10 times in 10 miles: 12.7% (3) Acceleration at 6 mph/sec to 35 mph and deceleration at same rate 20 times in 10 miles: 20.7% At 3 mph/sec, or 1.34 m/s (0 to 60 mph in 20 sec). Then the same three scenarios give 2.4%, 12%, and 20%, so a factor of 2 slower rate doesn’t change the result that much. At 2 mph/sec acceleration/deceleration rate the three scenarios give 2.2%, 11%, and 19%. Increasing total miles traveled, d, to 30 in scenario (1) gives 0.9%. Increasing stops in this scenario to 3, with 30 miles total, gives 2.7%. Increasing vehicle mass increases the percentage of energy recovered, but it’s a small effect for larger number of stop/starts. For example the first scenario goes from 2.7% to 3.8%, second goes from 12.7% to 14.7%, third goes from 20.7% to 23.2% if vehicle mass is doubled. Decreasing losses in the motor/controller and drive train of course increases the energy recovered. For example, decreasing motor/controller loss to 15% in scenario (2) increases the energy gained from 12.7% to 16.5%. -- View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Range-vs-Speed-tp4672366p4672477.html Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
For my part, this has been blabbering on about theory, because I enjoy it. In the world operate on a much simpler level. If I want to think I am reducing energy consumption, I seek a lower average speed. Not much else helps to the same extent. Skinny tires, better regen efficiency, hidden wiper blades, lower overall height?meh. Driving slower is by far the easiest to do, and the most cost effective - unless you just hate being behind the wheel, it is cost free. I don't think you can do much better than pick the right vehicle and then take your time. On Sun, Nov 9, 2014 at 11:51 AM, Robert Bruninga via EV ev@lists.evdl.org wrote: This analysis is missing something when it implies that more and more energy is recoverd when more and more stops are made along the same 10 miles. This is voodoo economics. Yes, the perecentages of energy recovered go up but there is no mention of how drastically the total energy goes up with the more and more stops. I could drive with one foot on regen and one on the acceperator continuously and maybe force 30% recovered energy, but at a huge overall loss. Bob -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Al via EV Sent: Saturday, November 08, 2014 11:02 PM To: tomw; Electric Vehicle Discussion List Subject: Re: [EVDL] Range vs Speed Nice explaination Tom. Al - Original Message - From: tomw via EV ev@lists.evdl.org To: ev@lists.evdl.org Sent: Saturday, November 08, 2014 10:36 AM Subject: Re: [EVDL] Range vs Speed I looked at the effect of acceleration and deceleration rates on energy used per acceleration-deceleration cycle a while back. To simplify the calculation I assumed the same rate for acceleration and deceleration. You do get more energy into the pack stopping faster with regen. For example, at a faster deceleration rate, 6 mph/sec, 7.7% of the vehicle K.E. is lost to work against drag and rolling resistance forces, and at a slower deceleration rate, 2 mph/sec, 23.1% is lost. If you assume a combined motor/controller loss of 20% and drive train loss of 10%, then for the faster deceleration rate 100 – (20 + 10 + 7.7) = 62% of vehicle kinetic energy goes into the battery pack, and at the slower deceleration rate 100 – (20 + 10 + 23.1) = 47% goes into the battery pack. However, you don't get a lot of difference in energy into the pack as a percentage of total energy used when considering a trip with travel at constant speed and a number of acceleration-deceleration cycles. For Example: (1) My car accelerates at 6 mph/sec to 60 mph, drives 10 miles, then decelerates at the same rate to a stop, estimated percent of total energy used that is regained with regen is: 2.7% (2) Acceleration at 6 mph/sec to 35 mph and deceleration at same rate 10 times in 10 miles: 12.7% (3) Acceleration at 6 mph/sec to 35 mph and deceleration at same rate 20 times in 10 miles: 20.7% At 3 mph/sec, or 1.34 m/s (0 to 60 mph in 20 sec). Then the same three scenarios give 2.4%, 12%, and 20%, so a factor of 2 slower rate doesn’t change the result that much. At 2 mph/sec acceleration/deceleration rate the three scenarios give 2.2%, 11%, and 19%. Increasing total miles traveled, d, to 30 in scenario (1) gives 0.9%. Increasing stops in this scenario to 3, with 30 miles total, gives 2.7%. Increasing vehicle mass increases the percentage of energy recovered, but it’s a small effect for larger number of stop/starts. For example the first scenario goes from 2.7% to 3.8%, second goes from 12.7% to 14.7%, third goes from 20.7% to 23.2% if vehicle mass is doubled. Decreasing losses in the motor/controller and drive train of course increases the energy recovered. For example, decreasing motor/controller loss to 15% in scenario (2) increases the energy gained from 12.7% to 16.5%. -- View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Range-vs-Speed-tp4672366p4672477.html Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I
Re: [EVDL] Range vs Speed
Those were also the tires for the gen 1 USA Prius, although I believe they have stopped making them and I have had very good results with other LRR tires such as Sumitomo HTR. Soon I will need to put new tires on my 2002 Prius again, so I will again have to search and find a low cost LRR tire with decent reviews. Regards, Cor van de Water Chief Scientist Proxim Wireless Corporation http://www.proxim.com Email: cwa...@proxim.com Private: http://www.cvandewater.info Skype: cor_van_de_water Tel: +1 408 383 7626 -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Rush Dougherty via EV Sent: Sunday, November 09, 2014 7:53 PM To: 'Electric Vehicle Discussion List' Subject: Re: [EVDL] Range vs Speed The right LRR tires makes a big difference also. When I had to replace my year 2000 Honda Insight tires about 5 years ago, I went to my local Discount Tire place and said I wanted the OEM tires, Bridgestone Potenza RE 92's. The sales man came back with, 'We have another Low Rolling Resistance tire that is just as good as the Potenza, and they are a little cheaper for 4 and have a better mileage rating, 60,000 instead of 40,000. He said the magic word - LRR so I said sure put 'em on. Well, about an hour later I drove out of the parking lot with the new tires and I knew immediately that I'd get much lower MPG. I drove around for about 15 minutes and sure enough I was getting 50 mpg instead of my usual 60 mpg, I drove back and said I don't want these, please change them out for the Potenza's. Salesman was very nice and said, no problem, but we'll have to order them. That was why he pushed the other tires, the Potenza's were not in stock and it took 2 weeks to get them. So if you have an 1st Gen Honda Insight, use only Potenza RE 92 tires. Rush Tucson AZ -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Lee Hart via EV Sent: Sunday, November 09, 2014 3:45 PM To: Michael Ross; Electric Vehicle Discussion List Subject: Re: [EVDL] Range vs Speed Michael Ross via EV wrote: If I want to think I am reducing energy consumption, I seek a lower average speed. Not much else helps to the same extent. Skinny tires, better regen efficiency, hidden wiper blades, lower overall height?... meh. I agree on regen, hidden wipers, and lower height. But tires really do make a big difference. There is at least a 2:1 difference in the rolling resistance of otherwise similar tires. This translates into about a 10-20% difference in range (more at low speeds where tires are a big part of your losses; less at high speeds where wind resistance dominates). The trouble is, it's hard to find data on rolling resistance. Your best bet is usually to get OEM tires from some car that needs to have good gas mileage. (Note that the tires sold in tire stores are NOT the same tires that car manufacturers get!) Tire pressure, wheel alignment, and dragging brakes also make a big difference. Most tires get underinflated for a cushy ride, or just because no one has checked the pressure in months. Wheel alignment is also likely to be off. And *most* car's brakes drag, with the pads constantly running against the calipers because there aren't really any spring retractors. -- A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away. -- Antoine de Saint Exupery -- Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
On Sun Nov 09 19:52:56 PST 2014 ev@lists.evdl.org said: The right LRR tires makes a big difference also. When I had to replace my year My problem is finding a LRR tire that fits a Ford F-250 truck... -- Try my Sensible Email package! https://sourceforge.net/projects/sensibleemail/ ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
The subject of the Potenza's not being manufactured comes up on the www.Insightcentral.net every couple months and it seems that they are just in short supply and it take a little while for the production to filter down to the retailers. Tire rack usually has them. Rush Tucson AZ -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Cor van de Water via EV Sent: Sunday, November 09, 2014 9:12 PM To: Electric Vehicle Discussion List Subject: Re: [EVDL] Range vs Speed Those were also the tires for the gen 1 USA Prius, although I believe they have stopped making them and I have had very good results with other LRR tires such as Sumitomo HTR. Soon I will need to put new tires on my 2002 Prius again, so I will again have to search and find a low cost LRR tire with decent reviews. Regards, Cor van de Water Chief Scientist Proxim Wireless Corporation http://www.proxim.com Email: cwa...@proxim.com Private: http://www.cvandewater.info Skype: cor_van_de_water Tel: +1 408 383 7626 -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Rush Dougherty via EV Sent: Sunday, November 09, 2014 7:53 PM To: 'Electric Vehicle Discussion List' Subject: Re: [EVDL] Range vs Speed The right LRR tires makes a big difference also. When I had to replace my year 2000 Honda Insight tires about 5 years ago, I went to my local Discount Tire place and said I wanted the OEM tires, Bridgestone Potenza RE 92's. The sales man came back with, 'We have another Low Rolling Resistance tire that is just as good as the Potenza, and they are a little cheaper for 4 and have a better mileage rating, 60,000 instead of 40,000. He said the magic word - LRR so I said sure put 'em on. Well, about an hour later I drove out of the parking lot with the new tires and I knew immediately that I'd get much lower MPG. I drove around for about 15 minutes and sure enough I was getting 50 mpg instead of my usual 60 mpg, I drove back and said I don't want these, please change them out for the Potenza's. Salesman was very nice and said, no problem, but we'll have to order them. That was why he pushed the other tires, the Potenza's were not in stock and it took 2 weeks to get them. So if you have an 1st Gen Honda Insight, use only Potenza RE 92 tires. Rush Tucson AZ -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Lee Hart via EV Sent: Sunday, November 09, 2014 3:45 PM To: Michael Ross; Electric Vehicle Discussion List Subject: Re: [EVDL] Range vs Speed Michael Ross via EV wrote: If I want to think I am reducing energy consumption, I seek a lower average speed. Not much else helps to the same extent. Skinny tires, better regen efficiency, hidden wiper blades, lower overall height?... meh. I agree on regen, hidden wipers, and lower height. But tires really do make a big difference. There is at least a 2:1 difference in the rolling resistance of otherwise similar tires. This translates into about a 10-20% difference in range (more at low speeds where tires are a big part of your losses; less at high speeds where wind resistance dominates). The trouble is, it's hard to find data on rolling resistance. Your best bet is usually to get OEM tires from some car that needs to have good gas mileage. (Note that the tires sold in tire stores are NOT the same tires that car manufacturers get!) Tire pressure, wheel alignment, and dragging brakes also make a big difference. Most tires get underinflated for a cushy ride, or just because no one has checked the pressure in months. Wheel alignment is also likely to be off. And *most* car's brakes drag, with the pads constantly running against the calipers because there aren't really any spring retractors. -- A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away. -- Antoine de Saint Exupery -- Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev
Re: [EVDL] Range vs Speed
Hi John and All, Have you tried commercial high pressure truck tires which have always been made LRR? You lose some traction, ride, but gain range. Jerry Dycus From: John Lussmyer via EV ev@lists.evdl.org To: Electric Vehicle Discussion List ev@lists.evdl.org; Rush Dougherty r...@ironandwood.org Sent: Sunday, November 9, 2014 11:12 PM Subject: Re: [EVDL] Range vs Speed On Sun Nov 09 19:52:56 PST 2014 ev@lists.evdl.org said: The right LRR tires makes a big difference also. When I had to replace my year My problem is finding a LRR tire that fits a Ford F-250 truck... -- Try my Sensible Email package! https://sourceforge.net/projects/sensibleemail/ ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ques -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141110/6543d19c/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
Yup... I put up two pdf's about LRR, one from Green Seal in Mar 2003, the other from the Transportation Research Board in 2006 http://tucsonev.com/LRR.html Old, but the info is still good. Hopefully there are still some tires being manufactured... Rush www.TucsonEV.com -Original Message- From: John Lussmyer [mailto:cou...@casadelgato.com] Sent: Sunday, November 09, 2014 9:13 PM To: Electric Vehicle Discussion List; Rush Dougherty Subject: Re: Range vs Speed On Sun Nov 09 19:52:56 PST 2014 ev@lists.evdl.org said: The right LRR tires makes a big difference also. When I had to replace my year My problem is finding a LRR tire that fits a Ford F-250 truck... -- Try my Sensible Email package! https://sourceforge.net/projects/sensibleemail/ ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
Tirerack is showing the Bridgestone Potenza RE92 in 175/65R14 in closeout (Fewer than 2 tires available) since some time, so if they are still being made, then Tirerack si not showing it because when you try to order the Fewer than 2 tires a warning pops up saying: The specially-priced closeout items you are buying are first quality products covered by applicable manufacturers' limited warranties. They are, however, available only until our current inventory is depleted. Cor van de Water Chief Scientist Proxim Wireless Corporation http://www.proxim.com Email: cwa...@proxim.com Private: http://www.cvandewater.info Skype: cor_van_de_water Tel: +1 408 383 7626 -Original Message- From: Rush Dougherty [mailto:r...@ironandwood.org] Sent: Sunday, November 09, 2014 8:35 PM To: Cor van de Water; 'Electric Vehicle Discussion List' Subject: RE: [EVDL] Range vs Speed The subject of the Potenza's not being manufactured comes up on the www.Insightcentral.net every couple months and it seems that they are just in short supply and it take a little while for the production to filter down to the retailers. Tire rack usually has them. Rush Tucson AZ -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Cor van de Water via EV Sent: Sunday, November 09, 2014 9:12 PM To: Electric Vehicle Discussion List Subject: Re: [EVDL] Range vs Speed Those were also the tires for the gen 1 USA Prius, although I believe they have stopped making them and I have had very good results with other LRR tires such as Sumitomo HTR. Soon I will need to put new tires on my 2002 Prius again, so I will again have to search and find a low cost LRR tire with decent reviews. Regards, Cor van de Water Chief Scientist Proxim Wireless Corporation http://www.proxim.com Email: cwa...@proxim.com Private: http://www.cvandewater.info Skype: cor_van_de_water Tel: +1 408 383 7626 -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Rush Dougherty via EV Sent: Sunday, November 09, 2014 7:53 PM To: 'Electric Vehicle Discussion List' Subject: Re: [EVDL] Range vs Speed The right LRR tires makes a big difference also. When I had to replace my year 2000 Honda Insight tires about 5 years ago, I went to my local Discount Tire place and said I wanted the OEM tires, Bridgestone Potenza RE 92's. The sales man came back with, 'We have another Low Rolling Resistance tire that is just as good as the Potenza, and they are a little cheaper for 4 and have a better mileage rating, 60,000 instead of 40,000. He said the magic word - LRR so I said sure put 'em on. Well, about an hour later I drove out of the parking lot with the new tires and I knew immediately that I'd get much lower MPG. I drove around for about 15 minutes and sure enough I was getting 50 mpg instead of my usual 60 mpg, I drove back and said I don't want these, please change them out for the Potenza's. Salesman was very nice and said, no problem, but we'll have to order them. That was why he pushed the other tires, the Potenza's were not in stock and it took 2 weeks to get them. So if you have an 1st Gen Honda Insight, use only Potenza RE 92 tires. Rush Tucson AZ -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Lee Hart via EV Sent: Sunday, November 09, 2014 3:45 PM To: Michael Ross; Electric Vehicle Discussion List Subject: Re: [EVDL] Range vs Speed Michael Ross via EV wrote: If I want to think I am reducing energy consumption, I seek a lower average speed. Not much else helps to the same extent. Skinny tires, better regen efficiency, hidden wiper blades, lower overall height?... meh. I agree on regen, hidden wipers, and lower height. But tires really do make a big difference. There is at least a 2:1 difference in the rolling resistance of otherwise similar tires. This translates into about a 10-20% difference in range (more at low speeds where tires are a big part of your losses; less at high speeds where wind resistance dominates). The trouble is, it's hard to find data on rolling resistance. Your best bet is usually to get OEM tires from some car that needs to have good gas mileage. (Note that the tires sold in tire stores are NOT the same tires that car manufacturers get!) Tire pressure, wheel alignment, and dragging brakes also make a big difference. Most tires get underinflated for a cushy ride, or just because no one has checked the pressure in months. Wheel alignment is also likely to be off. And *most* car's brakes drag, with the pads constantly running against the calipers because there aren't really any spring retractors. -- A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away. -- Antoine de Saint Exupery -- Lee Hart's EV projects are at http://www.sunrise-ev.com
Re: [EVDL] Range vs Speed
I looked at the effect of acceleration and deceleration rates on energy used per acceleration-deceleration cycle a while back. To simplify the calculation I assumed the same rate for acceleration and deceleration. You do get more energy into the pack stopping faster with regen. For example, at a faster deceleration rate, 6 mph/sec, 7.7% of the vehicle K.E. is lost to work against drag and rolling resistance forces, and at a slower deceleration rate, 2 mph/sec, 23.1% is lost. If you assume a combined motor/controller loss of 20% and drive train loss of 10%, then for the faster deceleration rate 100 – (20 + 10 + 7.7) = 62% of vehicle kinetic energy goes into the battery pack, and at the slower deceleration rate 100 – (20 + 10 + 23.1) = 47% goes into the battery pack. However, you don't get a lot of difference in energy into the pack as a percentage of total energy used when considering a trip with travel at constant speed and a number of acceleration-deceleration cycles. For Example: (1) My car accelerates at 6 mph/sec to 60 mph, drives 10 miles, then decelerates at the same rate to a stop, estimated percent of total energy used that is regained with regen is: 2.7% (2) Acceleration at 6 mph/sec to 35 mph and deceleration at same rate 10 times in 10 miles: 12.7% (3) Acceleration at 6 mph/sec to 35 mph and deceleration at same rate 20 times in 10 miles: 20.7% At 3 mph/sec, or 1.34 m/s (0 to 60 mph in 20 sec). Then the same three scenarios give 2.4%, 12%, and 20%, so a factor of 2 slower rate doesn’t change the result that much. At 2 mph/sec acceleration/deceleration rate the three scenarios give 2.2%, 11%, and 19%. Increasing total miles traveled, d, to 30 in scenario (1) gives 0.9%. Increasing stops in this scenario to 3, with 30 miles total, gives 2.7%. Increasing vehicle mass increases the percentage of energy recovered, but it’s a small effect for larger number of stop/starts. For example the first scenario goes from 2.7% to 3.8%, second goes from 12.7% to 14.7%, third goes from 20.7% to 23.2% if vehicle mass is doubled. Decreasing losses in the motor/controller and drive train of course increases the energy recovered. For example, decreasing motor/controller loss to 15% in scenario (2) increases the energy gained from 12.7% to 16.5%. -- View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Range-vs-Speed-tp4672366p4672477.html Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
/The wind losses are proportional to the cube of *speed* period./ To clarify, the drag force is proportional to vehicle speed squared. Power, or energy/time, is the product of this force and vehicle speed, so is proportional to speed cubed. Then the work done per unit time against this force is proportional to the cube of vehicle speed, which is what I think is meant in the above by wind losses. -- View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Range-vs-Speed-tp4672366p4672479.html Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
Nice explaination Tom. Al - Original Message - From: tomw via EV ev@lists.evdl.org To: ev@lists.evdl.org Sent: Saturday, November 08, 2014 10:36 AM Subject: Re: [EVDL] Range vs Speed I looked at the effect of acceleration and deceleration rates on energy used per acceleration-deceleration cycle a while back. To simplify the calculation I assumed the same rate for acceleration and deceleration. You do get more energy into the pack stopping faster with regen. For example, at a faster deceleration rate, 6 mph/sec, 7.7% of the vehicle K.E. is lost to work against drag and rolling resistance forces, and at a slower deceleration rate, 2 mph/sec, 23.1% is lost. If you assume a combined motor/controller loss of 20% and drive train loss of 10%, then for the faster deceleration rate 100 – (20 + 10 + 7.7) = 62% of vehicle kinetic energy goes into the battery pack, and at the slower deceleration rate 100 – (20 + 10 + 23.1) = 47% goes into the battery pack. However, you don't get a lot of difference in energy into the pack as a percentage of total energy used when considering a trip with travel at constant speed and a number of acceleration-deceleration cycles. For Example: (1) My car accelerates at 6 mph/sec to 60 mph, drives 10 miles, then decelerates at the same rate to a stop, estimated percent of total energy used that is regained with regen is: 2.7% (2) Acceleration at 6 mph/sec to 35 mph and deceleration at same rate 10 times in 10 miles: 12.7% (3) Acceleration at 6 mph/sec to 35 mph and deceleration at same rate 20 times in 10 miles: 20.7% At 3 mph/sec, or 1.34 m/s (0 to 60 mph in 20 sec). Then the same three scenarios give 2.4%, 12%, and 20%, so a factor of 2 slower rate doesn’t change the result that much. At 2 mph/sec acceleration/deceleration rate the three scenarios give 2.2%, 11%, and 19%. Increasing total miles traveled, d, to 30 in scenario (1) gives 0.9%. Increasing stops in this scenario to 3, with 30 miles total, gives 2.7%. Increasing vehicle mass increases the percentage of energy recovered, but it’s a small effect for larger number of stop/starts. For example the first scenario goes from 2.7% to 3.8%, second goes from 12.7% to 14.7%, third goes from 20.7% to 23.2% if vehicle mass is doubled. Decreasing losses in the motor/controller and drive train of course increases the energy recovered. For example, decreasing motor/controller loss to 15% in scenario (2) increases the energy gained from 12.7% to 16.5%. -- View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Range-vs-Speed-tp4672366p4672477.html Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
Nope, it is still only SPEED that has the impact on air drag. Yes, how you accelerate gets you to speed faster, but it is still only speed that causes air drag. And the below advice is just plain wrong. Getting on the regen”hard” means remaining at the highest speed for the longest possible time before slamming to a stop. No, far better to coast as long as possible to that next stop. Thus reducing the speed sooner. Bob *From:* Michael Ross [mailto:michael.e.r...@gmail.com] *Sent:* Thursday, November 06, 2014 1:54 PM *To:* Robert Bruninga; Electric Vehicle Discussion List *Subject:* Re: [EVDL] Range vs Speed Yep, It is the speed. However, if you always accelerate hard you will spend more time cubing your higher speed as drag losses, than if you take it easy and go easy cubing a lower speed for a longer time. So, take it easy speeding up, and get on the regen hard to slow down (reduce that cubed high speed as much as possible). On Thu, Nov 6, 2014 at 1:41 PM, Robert Bruninga via EV ev@lists.evdl.org wrote: Slower acceleration leads to lower average speed. Which leads to lower wind losses. Not at tall. You can take all the time y ou want to get to 70 PMH, but it is not acceleration that is causing the wind loss, it is *speed*. The wind losses are proportional to the cube of *speed* period. You can accelerate to a high speed or you can coast down a hill, in either case, it is *speed* that is the only variable we are talking about there. The fact that acceleration causes speed is a second-order effect. And just confuses the layman Bob -Original Message- From: Willie2 [mailto:wmckem...@gmail.com] Sent: Thursday, November 06, 2014 9:51 AM To: Robert Bruninga; Electric Vehicle Discussion List Subject: Re: [EVDL] Range vs Speed Generally, correct. On 11/06/2014 07:49 AM, Robert Bruninga via EV wrote: Energy used in driving is simple physics: Everything you put into acceleration you get back in Momentum. Everything you put into a hill, you get back as potential energy. Everything you put into braking is LOST (regen gains some back). Wind resistance goes up as the cube of speed. True, but I believe, per unit distance traveled, energy lost to wind friction goes up with the square of the speed. That is, in a given amount of time, you cover more distance at high speed than at lower. You experience the higher wind resistance for a shorter period of time. So the only real control you have over energy is keeping the speed (wind resistance) down. Gas cars are actually MORE efficient at high acceleration when the throttle plate is wide open and the pumping losses are minimized. So creeping away from a traffic light does not really gain anything. BUT, if it is a typical gas car and the engine then keeps running during the coast phase, that too is 100% waste (engine running but doing nothing). When people say go light on the accelerator they are not talking about the rate of acceleration at all. They are talking about DON'T OVER ACCELERATE beyond what it takes to coast to the next stop without having to use the brakes. Slower acceleration leads leads to lower average speed. Which leads to lower wind losses. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama* Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. *Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html* A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141107/69c637fc/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
I think people tend to generalize, thinking high speed must be high-consumption and low speed low. As in most things, it depends. If you rive for low consumption, high speed can be pretty economical. I've seen this with my ICE vehicle watching the real time consumption readout, sometimes see 50+ mpg at a steady, level 80 mph. Conversely, if your slow return trip was filled with a bazillion starts and stops, each will take more energy to accelerate the vehicle than a steady cruise. Chris On Thu, Nov 6, 2014 at 12:43 AM, John Lussmyer via EV ev@lists.evdl.org wrote: I'm not seeing much difference in power usage at different speeds. Last night, I drove 60 miles on the highway/freeway, almost entirely at 60mph. used 125AH out of my freshly charged pack. Tonight, I drove the return trip, taking almost an hour longer due to horrible slow traffic on the freeway. Often stopped or below 10mph. Same power usage. -- Tigers prowl and Dragons soar in my dreams... ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141106/a28a36a3/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
What you experience is obviously correct, but why is the fun part. The work done and energy consumed are how to get at it. If you start and stop at the same locations and take the same route, then changes in gravitational potential(height) wash out to 0. Then you are left with mass x acceleration, and frictional effects. Wind and air drag is the predominant loss and speed related - hence the wonderment about not much difference. Rolling resistance is not that big a deal, comparatively; though you can certainly quibble over rough roads and ire heating etc. The mass doesn't really change, so you have to think about acceleration Acceleration is the area under the velocity curve. It is intuitively a little hard to think about this, but nothing says the fast easy trip has the same rate of change of velocity as the slow speed up and slow down trip. I vote for this as the factor mitigating air drag in the comparison. Perhaps if you took it very easy on the slow run you would see the greater energy losses appear in the the fast run. If there is regen involved then you have to know a bunch of details about how that works - but it is a possibility. The energy recovered is likely to be different - the two very different trips. Another possible contribution is prevailing winds during the trips. I have seen careful work done with streamlined bicycles and this can be a confounding factor in coast down testing of drag on bodywork. For valid results you need dead air when comparing bodywork changes. If the the wind is in you face more on the slow run, and from the rear during the fast run On Thu, Nov 6, 2014 at 6:12 AM, Chris Tromley via EV ev@lists.evdl.org wrote: I think people tend to generalize, thinking high speed must be high-consumption and low speed low. As in most things, it depends. If you rive for low consumption, high speed can be pretty economical. I've seen this with my ICE vehicle watching the real time consumption readout, sometimes see 50+ mpg at a steady, level 80 mph. Conversely, if your slow return trip was filled with a bazillion starts and stops, each will take more energy to accelerate the vehicle than a steady cruise. Chris On Thu, Nov 6, 2014 at 12:43 AM, John Lussmyer via EV ev@lists.evdl.org wrote: I'm not seeing much difference in power usage at different speeds. Last night, I drove 60 miles on the highway/freeway, almost entirely at 60mph. used 125AH out of my freshly charged pack. Tonight, I drove the return trip, taking almost an hour longer due to horrible slow traffic on the freeway. Often stopped or below 10mph. Same power usage. -- Tigers prowl and Dragons soar in my dreams... ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141106/a28a36a3/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141106/524028cd/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
Energy used in driving is simple physics: Everything you put into acceleration you get back in Momentum. Everything you put into a hill, you get back as potential energy. Everything you put into braking is LOST (regen gains some back). Wind resistance goes up as the cube of speed. So the only real control you have over energy is keeping the speed (wind resistance) down. Gas cars are actually MORE efficient at high acceleration when the throttle plate is wide open and the pumping losses are minimized. So creeping away from a traffic light does not really gain anything. BUT, if it is a typical gas car and the engine then keeps running during the coast phase, that too is 100% waste (engine running but doing nothing). When people say go light on the accelerator they are not talking about the rate of acceleration at all. They are talking about DON'T OVER ACCELERATE beyond what it takes to coast to the next stop without having to use the brakes. Bob, WB4APR -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of John Lussmyer via EV Sent: Thursday, November 06, 2014 12:44 AM To: Electric Vehicle Discussion List Subject: [EVDL] Range vs Speed I'm not seeing much difference in power usage at different speeds. Last night, I drove 60 miles on the highway/freeway, almost entirely at 60mph. used 125AH out of my freshly charged pack. Tonight, I drove the return trip, taking almost an hour longer due to horrible slow traffic on the freeway. Often stopped or below 10mph. Same power usage. -- Tigers prowl and Dragons soar in my dreams... ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
/“Then you are left with mass x acceleration, and frictional effects. Wind and air drag is the predominant loss and speed related - hence the wonderment about not much difference. Rolling resistance is not that big a deal, comparatively; though you can certainly quibble over rough roads and ire heating etc.”/ The relative work done against rolling resistance and drag forces varies with vehicle weight and CdA. A heavy car with low CdA such as the Tesla S will have less increase in energy consumption with vehicle speed due to a larger ratio of rolling resistance force to drag force compared to a light, blocky vehicle with relatively large CdA. The two forces are equal at around 40 – 50 mph for typical sedan type vehicles with Cd = 0.32. Rolling resistance force is larger below, and drag force is larger above. Rolling resistance force is a fairly constant ~ 30 lb, and drag force ~60 lb for my car at 60 mph, so if rolling resistance force was neglected at this speed, you would be neglecting about 1/3 of the force on the vehicle. /“Acceleration is the area under the velocity curve.”/ The opposite. Acceleration is the change in velocity with time, so the derivative of velocity with respect to time. Integrating acceleration over time gives velocity. /“Everything you put into acceleration you get back in Momentum. Everything you put into a hill, you get back as potential energy.”/ Yes, if you drive on a frictionless surface in a vacuum in a vehicle with no losses. In the real world you do work against rolling resistance and drag forces during acceleration, as well as lose energy to motor/controller inefficiencies and drive train friction, so only a portion of the work done is converted to vehicle kinetic energy. You also lose energy to those when decelerating, and when going up a hill and when going down. I’ve found the opposite of these reported results. I did a 64 mile round trip mainly on interstate in normal conditions at 60-65 mph, and a trip during road construction where we crept along at 10-20 mph with constant stop/start for around 15 miles of the trip each way. Energy consumption was significantly smaller during the trip with construction. I was accelerating very slowly to very low speeds, coasting a bit, then lightly braking to stop, so not much energy was used during each acceleration. Energy consumption would be significantly higher if you are repeatedly accelerating quickly to higher speeds then quickly slowed with little or no coasting in between. I also have regen so regained some energy during each deceleration, but very little since I left clearance to the car in front of me so that after each slow acceleration I could coast until my car slowed to 5mph or less before braking (with regen). -- View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Range-vs-Speed-tp4672366p4672379.html Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
Generally, correct. On 11/06/2014 07:49 AM, Robert Bruninga via EV wrote: Energy used in driving is simple physics: Everything you put into acceleration you get back in Momentum. Everything you put into a hill, you get back as potential energy. Everything you put into braking is LOST (regen gains some back). Wind resistance goes up as the cube of speed. True, but I believe, per unit distance traveled, energy lost to wind friction goes up with the square of the speed. That is, in a given amount of time, you cover more distance at high speed than at lower. You experience the higher wind resistance for a shorter period of time. So the only real control you have over energy is keeping the speed (wind resistance) down. Gas cars are actually MORE efficient at high acceleration when the throttle plate is wide open and the pumping losses are minimized. So creeping away from a traffic light does not really gain anything. BUT, if it is a typical gas car and the engine then keeps running during the coast phase, that too is 100% waste (engine running but doing nothing). When people say go light on the accelerator they are not talking about the rate of acceleration at all. They are talking about DON'T OVER ACCELERATE beyond what it takes to coast to the next stop without having to use the brakes. Slower acceleration leads leads to lower average speed. Which leads to lower wind losses. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
I should have graphed it out for myself as a reminder. When you accelerate to speed up, the work done (velocity is changed) is in one direction,and when you slow down in the other. You sum positive and negative acceleration, and when you have stopped the sum is zero. But the differences in acceleration do make difference when regen and wind are considered. More likely you slow down harder than you speed up, and at lower wind speeds, with some fractional recovery from regen. De-accelerating is actually enhanced at higher speeds by air drag, but regen loses out when the wind does the work. I wonder if you regen hard from high speeds - to beat the wind to the punch, then take it easy for the slower de-acceleration, at lower wind speeds, what that does? On Thu, Nov 6, 2014 at 8:49 AM, Robert Bruninga via EV ev@lists.evdl.org wrote: Energy used in driving is simple physics: Everything you put into acceleration you get back in Momentum. Everything you put into a hill, you get back as potential energy. Everything you put into braking is LOST (regen gains some back). Wind resistance goes up as the cube of speed. So the only real control you have over energy is keeping the speed (wind resistance) down. Gas cars are actually MORE efficient at high acceleration when the throttle plate is wide open and the pumping losses are minimized. So creeping away from a traffic light does not really gain anything. BUT, if it is a typical gas car and the engine then keeps running during the coast phase, that too is 100% waste (engine running but doing nothing). When people say go light on the accelerator they are not talking about the rate of acceleration at all. They are talking about DON'T OVER ACCELERATE beyond what it takes to coast to the next stop without having to use the brakes. Bob, WB4APR -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of John Lussmyer via EV Sent: Thursday, November 06, 2014 12:44 AM To: Electric Vehicle Discussion List Subject: [EVDL] Range vs Speed I'm not seeing much difference in power usage at different speeds. Last night, I drove 60 miles on the highway/freeway, almost entirely at 60mph. used 125AH out of my freshly charged pack. Tonight, I drove the return trip, taking almost an hour longer due to horrible slow traffic on the freeway. Often stopped or below 10mph. Same power usage. -- Tigers prowl and Dragons soar in my dreams... ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141106/c07ac7ee/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
It's never zero because of conservation of energy. I think Tesla says their electronics are only 80% efficient so you loose 20% on acceleration and another 20% on regen. Not counting other losses such as wind. From: Michael Ross via EV ev@lists.evdl.org To: Robert Bruninga bruni...@usna.edu; Electric Vehicle Discussion List ev@lists.evdl.org Sent: Thursday, November 6, 2014 10:10 AM Subject: Re: [EVDL] Range vs Speed I should have graphed it out for myself as a reminder. When you accelerate to speed up, the work done (velocity is changed) is in one direction,and when you slow down in the other. You sum positive and negative acceleration, and when you have stopped the sum is zero. But the differences in acceleration do make difference when regen and wind are considered. More likely you slow down harder than you speed up, and at lower wind speeds, with some fractional recovery from regen. De-accelerating is actually enhanced at higher speeds by air drag, but regen loses out when the wind does the work. I wonder if you regen hard from high speeds - to beat the wind to the punch, then take it easy for the slower de-acceleration, at lower wind speeds, what that does? On Thu, Nov 6, 2014 at 8:49 AM, Robert Bruninga via EV ev@lists.evdl.org wrote: Energy used in driving is simple physics: Everything you put into acceleration you get back in Momentum. Everything you put into a hill, you get back as potential energy. Everything you put into braking is LOST (regen gains some back). Wind resistance goes up as the cube of speed. So the only real control you have over energy is keeping the speed (wind resistance) down. Gas cars are actually MORE efficient at high acceleration when the throttle plate is wide open and the pumping losses are minimized. So creeping away from a traffic light does not really gain anything. BUT, if it is a typical gas car and the engine then keeps running during the coast phase, that too is 100% waste (engine running but doing nothing). When people say go light on the accelerator they are not talking about the rate of acceleration at all. They are talking about DON'T OVER ACCELERATE beyond what it takes to coast to the next stop without having to use the brakes. Bob, WB4APR -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of John Lussmyer via EV Sent: Thursday, November 06, 2014 12:44 AM To: Electric Vehicle Discussion List Subject: [EVDL] Range vs Speed I'm not seeing much difference in power usage at different speeds. Last night, I drove 60 miles on the highway/freeway, almost entirely at 60mph. used 125AH out of my freshly charged pack. Tonight, I drove the return trip, taking almost an hour longer due to horrible slow traffic on the freeway. Often stopped or below 10mph. Same power usage. -- Tigers prowl and Dragons soar in my dreams... ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141106/c07ac7ee/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141106/ecee185a/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
Except maybe it is a brick at low speeds too? The drag of a bluff body might not change all that much and be terrible a low Reynolds numbers. I can't remember such things without looking them up. On Thu, Nov 6, 2014 at 12:38 PM, John Lussmyer via EV ev@lists.evdl.org wrote: I should have mentioned, this is with my electric F-250. Aerodynamics of a brick. I was REALLY expecting the much higher aero losses at high speed to make a measureable difference. On Wed Nov 05 21:43:42 PST 2014 ev@lists.evdl.org said: I'm not seeing much difference in power usage at different speeds. Last night, I drove 60 miles on the highway/freeway, almost entirely at 60mph. used 125AH out of my freshly charged pack. Tonight, I drove the return trip, taking almost an hour longer due to horrible slow traffic on the freeway. Often stopped or below 10mph. Same power usage. -- Worlds only All Electric F-250 truck! http://john.casadelgato.com/Electric-Vehicles/1995-Ford-F-250 ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141106/8a74f486/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
How much does it weigh? What everyone else accelerates on every stop-start is probably nothing compared to your situation. Chris On Nov 6, 2014 12:38 PM, John Lussmyer via EV ev@lists.evdl.org wrote: I should have mentioned, this is with my electric F-250. Aerodynamics of a brick. I was REALLY expecting the much higher aero losses at high speed to make a measureable difference. On Wed Nov 05 21:43:42 PST 2014 ev@lists.evdl.org said: I'm not seeing much difference in power usage at different speeds. Last night, I drove 60 miles on the highway/freeway, almost entirely at 60mph. used 125AH out of my freshly charged pack. Tonight, I drove the return trip, taking almost an hour longer due to horrible slow traffic on the freeway. Often stopped or below 10mph. Same power usage. -- Worlds only All Electric F-250 truck! http://john.casadelgato.com/Electric-Vehicles/1995-Ford-F-250 ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141106/e1386dca/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
Oh, around 6200 lbs I think. On Thu Nov 06 09:53:15 PST 2014 ctrom...@gmail.com said: How much does it weigh? What everyone else accelerates on every stop-start is probably nothing compared to your situation. Chris On Nov 6, 2014 12:38 PM, John Lussmyer via EV ev@lists.evdl.org wrote: I should have mentioned, this is with my electric F-250. Aerodynamics of a brick. I was REALLY expecting the much higher aero losses at high speed to make a measureable difference. On Wed Nov 05 21:43:42 PST 2014 ev@lists.evdl.org said: I'm not seeing much difference in power usage at different speeds. Last night, I drove 60 miles on the highway/freeway, almost entirely at 60mph. used 125AH out of my freshly charged pack. Tonight, I drove the return trip, taking almost an hour longer due to horrible slow traffic on the freeway. Often stopped or below 10mph. Same power usage. -- Worlds only All Electric F-250 truck! http://john.casadelgato.com/Electric-Vehicles/1995-Ford-F-250 ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- Tigers prowl and Dragons soar in my dreams... ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
What things like heat or AC do you have? They were running for an additional hour on the way back. -- charles On Nov 6, 2014, at 12:38 PM, John Lussmyer via EV ev@lists.evdl.org wrote: I should have mentioned, this is with my electric F-250. Aerodynamics of a brick. I was REALLY expecting the much higher aero losses at high speed to make a measureable difference. On Wed Nov 05 21:43:42 PST 2014 ev@lists.evdl.org said: I'm not seeing much difference in power usage at different speeds. Last night, I drove 60 miles on the highway/freeway, almost entirely at 60mph. used 125AH out of my freshly charged pack. Tonight, I drove the return trip, taking almost an hour longer due to horrible slow traffic on the freeway. Often stopped or below 10mph. Same power usage. -- Worlds only All Electric F-250 truck! http://john.casadelgato.com/Electric-Vehicles/1995-Ford-F-250 ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Range vs Speed
There's definitely a huge reduction in consumption when I drive at a steady ~30-40mph in traffic compared to 65mph+. Some days, when the charger fails me, I pray for traffic so I can make it home. Surface streets with all the stop signs and lights however don't reduce my consumption nearly as much. My car is the reciprocal of yours but the physics remain the same. Of course, if you have very high tear loads then the longer run time will cut into any reduction in miles per kWh. Do you run 4wd? A miss-match in tire size could cause high losses. On Thu, Nov 6, 2014 at 9:38 AM, John Lussmyer via EV ev@lists.evdl.org wrote: I should have mentioned, this is with my electric F-250. Aerodynamics of a brick. I was REALLY expecting the much higher aero losses at high speed to make a measureable difference. On Wed Nov 05 21:43:42 PST 2014 ev@lists.evdl.org said: I'm not seeing much difference in power usage at different speeds. Last night, I drove 60 miles on the highway/freeway, almost entirely at 60mph. used 125AH out of my freshly charged pack. Tonight, I drove the return trip, taking almost an hour longer due to horrible slow traffic on the freeway. Often stopped or below 10mph. Same power usage. -- Worlds only All Electric F-250 truck! http://john.casadelgato.com/Electric-Vehicles/1995-Ford-F-250 ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- www.electric-lemon.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141106/7bb5a542/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
