The trip computers aren't perfect either. The classic way of computing REAL fuel economy is always fill your tank carefully to the same "full" point, record the gallons, and divide by the miles driven (either from the trip odo, or the reading of the main odo at this fillup and the previous. It is hard to get exactly the same fill, so fuel used vs fuel added can easily differ by a gallon. It is best to average over a few tanks.
That is the way to compare reality to both the window sticker and the trip computer. For alternate fuels, you would first have to measure in the units in which it is dispensed then convert or adapt to using the dispensed units. (I don't understand Brits who laboriously determine MPG when their fuel is metered in liters.) ________________________________ From: Kilopascal <[email protected]> To: John M. Steele <[email protected]>; U.S. Metric Association <[email protected]> Sent: Sun, June 26, 2011 10:35:39 AM Subject: Re: [USMA:50747] Re: MPGe = miles per gallon equivalent? I would think they may have a benefactor who is supplying the funds during the time before they sell their vehicles and are able to recoup their costs. Yes, the money has to come from somewhere. I find it humorous that in an attempt to make up new units in order to inform the ignorant, it instead makes it more complex. Have they figured out a way for the average drive who has a difficulty in doing simple calculations to figure out from their driving how efficient their cars really are? Or will it all be up to on-board computers to give these people the numbers? It just seems that technology has become the medium by which the old units are given an extended life. Why change when you can have a computer convert easily modern metric units into old fashioned units? Between the '70s and now, the technology was developed to make metrication unnecessary. This isn't actually a good thing and actually creates a greater golf between those on the metric side and those on the pre-historic side. Metrication in the '70s was probably the last chance and now with the window closed the difficulties in dealing with the growing and prosperous metric world can only increase, even with technology that can let one see the numbers they prefer. From: John M. Steele Sent: Sunday, 2011-06-26 08:58 To: Kilopascal Subject: Re: [USMA:50747] Re: MPGe = miles per gallon equivalent? Maybe it will take them until introduction to build the current order book. However, it would seem to raise the question of what do they do for revenue in the meantime. We had a plant manager who used to say "Sometimes you have to shoot the engineers and just make product." The manufacturing staff should be able to make (and sell) the existing product while the engineering staff concentrates on the new product. In a quick read, the Wikipedia article seems mostly accurate, but is dead wrong on CAFE vs window sticker fuel economy. CAFE does not consider "well to wheels," it is a "tank to wheels" computation. However, it weights (by total miles) the ACTUAL dynometer performance on each segment. Because accessories are off, and the drive segements are not very reflective of real driving style, those actuals correspond VERY poor with real world (on roads) fuel economy of typical drivers.. For the window sticker, the city and highway figures are multiplied by "reality factors" (which the EPA standardized) and re-averaged by miles.. In reality, the "reality factors" vary between classes of cars, and high mileage cars are generally less likely to attain their window sticker in the real world than low mileage cars. ________________________________ From: Kilopascal <[email protected]> To: [email protected]; U.S. Metric Association <[email protected]> Sent: Sun, June 26, 2011 8:26:00 AM Subject: [USMA:50747] Re: MPGe = miles per gallon equivalent? You may find this of interest: http://mashable.com/2011/06/23/tesla-roadster-dead/ The Tesla Roadster electric car is dead (see update below). Tesla Motors announced Thursday it would stop taking orders for the $109,000 vehicle in two months, concentrating instead on the development of its next-generation Model S electric car, a four-door sedan that will cost about half as much. The iconic Tesla Roadster, now in version 2.5, has been a specialty two-seater from the get-go. It impressed reviewers with its snappy acceleration, sporty carbon-fiber body designed (update: and built) by Lotus, and relatively long 245-mile-rated range. But that $109,000 sticker price for the hand-built car — a “base price” that usually went much higher with sport options — proved too steep for the mass market. For mainstream drivers, Tesla announced plans for a lower-priced electric car in 2008. The Model S will sell for around $57,400 (up from its previously announced $49,000) when it’s ready for sale in mid-2012, according to The New York Times. We caught our first glimpse of a flashy Model S prototype at the Consumer Electronics Show last January, where we were awestruck by its sleek design and huge instrument panel powered by an Nvidia graphics processor. Update: While the Tesla Roadster as we know it is on its way out, a Tesla Motors spokesperson tells us “a version” of it is coming back: “The Roadster will always be the cornerstone of Tesla, and we look forward to bringing back a version of the supercar that takes full advantage of our advanced electric powertrain in the next several years.” Take a close-up look at the Model S, on which all of Tesla’s hopes are now pinned: A Wikipedia article on mpge: http://en.wikipedia.org/wiki/Miles_per_gallon_gasoline_equivalent ________________________________ No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1388 / Virus Database: 1513/3727 - Release Date: 06/26/11
