*Confusing units:* *They may be confusing all presented in one table, but they are all correct and most likely used somewhere in the world. The table is intended to provide ball-park figures for everyone, globally. Just ignore or delete those units that you do not like, or paste those that you do like into your own table. Easy to do in MSWord.* *If someone has reliable, ownership data collected over some 100 000 km of driving an electrical car (average electricity consumption of socket-to-wheel), I'd be delighted to include the results in the table. * *Stan*
On Mon, Jan 28, 2013 at 1:17 PM, John M. Steele <[email protected]>wrote: > Sorry, all the units got me confused. I meant to say MJ/km or per 100 km, > or even per megameter, energy/distance in any case. > > ----- Forwarded Message ---- > *From:* John M. Steele <[email protected]> > *To:* [email protected]; U.S. Metric Association <[email protected]> > *Cc:* U.S. Metric Association <[email protected]> > *Sent:* Mon, January 28, 2013 12:08:35 PM > *Subject:* Re: [USMA:52272] Re: Fuel economy in the real world getting > farther away from EPA estimates | cleveland.com > > Interesting. I'm not sure who your audience is or whether you are > looking for feedback. However, here are some thoughts. > > *Is the Passat an older car? Your reported fuel economy is MUCH better > than the current Monroney sticker for a 2013 diesel Passat > (city/combined/highway) 31/35/43. In the past few years, a lot of > emissions technology has been added to diesels to meet the current US > standard. I don't know if that explains the difference. > > *I agree with your tank-to-wheels and socket-to-wheels terminology and > that it reflects the way the vehicle's "fuel" economy is measured. > However, both petroleum products and electricity are metered at point of > sale. The term "meter-to-wheels" might be applied to either. Just a > thought, as it certainly isn't standard terminology yet. > > *I find presenting the data in every unit possible very confusing and hard > to read. My recommendation is to start with Monroney sticker info and > price per unit as used in the US, transform to proper SI, and do the > comparison in km/MJ. If your audience includes the metric-impaired, do an > auxilliary table underneath in US units, but avoid the flipping back and > forth on units. > > *From the Monroney sticker, I would include the Leaf's (99) MPGe rating as > well as the 34 kWh/100 miles and then expand on the story of mine-to-wheels > vs meter-to-wheels. Superficially, the Leaf sounds twice as good as the > Passat but is worse on a total life cycle basis (just looking at fuel, not > even thinking about manufacture of car and battery). I think that is the > key point, but perhaps it needs emphasis. > > *As diesel has a higher heat content than gasoline, there may be a slight > problem comparing diesel miles per gallon vs "gasoline equivalent" miles > per gallon. A gallon of diesel is about 1.137 gasoline equivalent gallons > based on Lower Heating Value. Of course, once you reduce all data to > km/MJ, problem solved. > > ------------------------------ > *From:* Stanislav Jakuba <[email protected]> > *To:* U.S. Metric Association <[email protected]> > *Cc:* U.S. Metric Association <[email protected]> > *Sent:* Mon, January 28, 2013 10:27:34 AM > *Subject:* [USMA:52272] Re: Fuel economy in the real world getting > farther away from EPA estimates | cleveland.com > > Attached is a detail comparison between a diesel and electric car. It may > not be easy to read, but so it is not easy to make the comparison. Try. > Stan Jakuba > > On Sun, Jan 27, 2013 at 10:00 AM, Kilopascal <[email protected]> wrote: > >> ** >> >> >> http://www.cleveland.com/business/index.ssf/2013/01/fuel_economy_in_the_real_world.html >> >> It seems that the fuel consumption ratings for the Ford Fusion aren't >> working out to what the EPA has published. Could this have anything to do >> with the fallacy of using mpg to measure consumption from a battery and not >> actual fuel usage? >> >> Those who might know more about the subject may wish to post a comment at >> the bottom of the article. Here is our chance to expose the fallacy of mpg >> when used in areas it doesn't belong in and offer a proper metric unit to >> give correct results. >> >> I might post later, if I'm convinced it is the use of mpg to measure >> something mpg is not intended and then mention the proper unit to use when >> I find out what it is. >> >> >> >> > >
