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. > > >
