> Steel/Aluminum: > 3/Y are steel frame as a cost reduction measure. Tesla used aluminum on S/X.
Correction: Model Y frames for lately built cars use aluminum sections from the Giga-press and are lighter than the previous steel ones. On Thu, Dec 30, 2021 at 2:49 PM Haudy Kazemi via EV <[email protected]> wrote: > Efficiency: > There are multiple legitimate ways to measure efficiency in terms of energy > consumption. What matters is that when one compares energy consumption, > that one knows what parts of the energy flow in the system are being > measured and compared. A vehicle tank-to-wheels efficiency measurement will > show lower kJ/mile than a well-to-wheels measurement. And the > well-to-wheels measurement will vary by production and refinery methods, > even if the vehicle remains the same. The measurement units may be the > same, but what they're measuring can vary, and may not be comparable. > > Steel/Aluminum: > 3/Y are steel frame as a cost reduction measure. Tesla used aluminum on > S/X. > > Even on bicycles, a steel frame and aluminum frame can be closer in weight > than one might assume. That's because aluminum has a brittle failure mode > that steel does not. Steel bends/stretches/is ductile when it is > approaching its limits. Aluminum tends to crack. The result is to ensure an > aluminum frame is strong enough to survive road shock, it must be built > from correspondingly larger/thicker parts than when steel is used. > > On a related note, that also means that there is a distinct advantage to > using steel for components that could lead to disaster if they experienced > a sudden failure. > > Aero: > Air resistance increases energy consumption at all speeds. It rapidly > becomes large at high speeds, as it increases by speed (actually velocity) > squared. There isn't a single speed across all vehicles where air > resistance becomes the dominant factor. 55 is just a rule of thumb, but > isn't actually a special value. A brick may be way under 55. A sleek > aircraft may be way over 55. > > The actual measured effect aero has on vehicle energy consumption is a > function of the drag coefficient (Cd) and exposed frontal area. A Prius can > have lower energy consumption than a motorcycle in part because it has a > lower Cd even though the frontal area is more. (The Atkinson cycle engine > also helps). > > Weight: > Weight has some effect of efficiency. It especially as an effect in terms > of acceleration/deceleration losses (which may be partially reduced via > gentle acceleration/regen). It also increases rolling resistance as a tire > deforms (which can be reduced via high tire pressures). Railroad cars have > pretty low rolling resistance...steel wheels on steel rail do not deform > much from increased weight. > > Effects on losses: > Wh/mile is a function of all of these factors. Which factor dominates will > vary by vehicle design, load, and driving pattern. An aerodynamic vehicle > will have lower aero losses than a brick. A lighter car will have lower > rolling resistance losses than an otherwise identical but heavier car. A > slow > driver will have lower aero losses than a fast driver. A steady route will > have lower losses than a stop and go route that has the same average speed. > > 3 mi/kWh aka 333 Wh/mi is a decent all around rule of thumb for many EVs > including the original Model S. It's enough to cover some electric > resistance cabin heating too. More efficient EVs that have better aero, and > HVAC heat pumps, and permanent magnet motors, including later updates to > Model S, have brought the number under 300. Model 3 and Y can be near 250 > Wh/mile or 4 mi/kWh, which matches Mark's observations. > > > > On Dec 30, 2021, 11:46 paul dove via EV <[email protected]> wrote: > > > Well, that’s not how efficiency is measured but I think I know what you > > mean. The Wh per mile is mostly a function of weight. Aero starts to > weigh > > in around 55mph. On conversions a good estimate is weight divided by 10. > My > > car weighs 3100 lbs with me in it and I got around 300wh/m. Tesla beat > this > > by making the battery a larger percentage of total weight by using > > aluminum. No one else comes close. I think the Bolt is close to the rule > of > > thumb. > > > > > > Sent from AT&T Yahoo Mail for iPhone > > > > > > On Thursday, December 30, 2021, 8:32 AM, Peri Hartman via EV < > > [email protected]> wrote: > > > > That's very cool to hear. I have heard over the years that the defacto > > EV efficiency is about 3 miles per kWh, measured at the battery, or 333 > > Wh per mile. So Tesla has done a great job. I wonder what the Bolt and > > some other longer range EVs can do. > > > > Peri > > > > << Annoyed by leaf blowers ? https://quietcleanseattle.org/ >> > > > > ------ Original Message ------ > > From: "Mark Hanson via EV" <[email protected]> > > To: [email protected] > > Cc: "Mark Hanson" <[email protected]> > > Sent: 30-Dec-21 06:17:32 > > Subject: [EVDL] Tesla Y actual wall outlet efficiency > > > > >Hi folks > > >My heavy 4400lb Tesla Y is more efficient than I thought, close to EPA > > rating, measured 265 watt hours per mile at the wall outlet with a GE KWh > > meter over 144 miles various hwy/city driving. The laptop screen car > > display shows 220-240 wh/mi at the car/battery which doesn’t include > > charger/batt inefficiencies. My previous electric Karmann Ghia 1974 > “ELEC > > KAR” tag was 330 wh/mi actual at the AC outlet. My Bolt and Leaf are > > slightly less efficient than the Tesla but all my conversions over the > > years were in the 330ish range, much less efficient than present day > > factory EVs. > > >Have a renewable energy efficient new year, > > >Mark > > > > > >Sent from my iPhone > > >_______________________________________________ > > >Address messages to [email protected] > > >No other addresses in TO and CC fields > > >UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > > >ARCHIVE: http://www.evdl.org/archive/ > > >LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > > > > _______________________________________________ > > Address messages to [email protected] > > No other addresses in TO and CC fields > > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > > ARCHIVE: http://www.evdl.org/archive/ > > LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > > > > > > > > -------------- next part -------------- > > An HTML attachment was scrubbed... > > URL: < > > > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20211230/c0957328/attachment.html > > > > > _______________________________________________ > > Address messages to [email protected] > > No other addresses in TO and CC fields > > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > > ARCHIVE: http://www.evdl.org/archive/ > > LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20211230/b8d85e56/attachment.html > > > _______________________________________________ > Address messages to [email protected] > No other addresses in TO and CC fields > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > ARCHIVE: http://www.evdl.org/archive/ > LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > -- *Paul Wujek* -------------- next part -------------- An HTML attachment was scrubbed... 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