EPA Proposes Grading System For Car Fuel Economy 272
suraj.sun writes with this snippet from CNET:
"The EPA and Department of Transportation on Monday proposed a fuel economy label overhaul to reflect how electric and alternative fuel vehicles stack up against gasoline passenger vehicles. ... The changed label, mandated by the 2007 energy law, includes the same information on city and highway miles per gallon and estimated driving costs based on 15,000 miles a year now available. But the new labels add more comparative information, rating cars on mileage, greenhouse gas contribution, and other air pollutants from tailpipe emissions. That means that consumers can look at a label to see how one vehicle compares to all available vehicles, rather than only cars in a specific class. One label proposes grades, ranging from an A-plus to a D. There are no failing grades, since vehicles need to comply with the Clean Air Act."
Re:Giant letter? (Score:3, Informative)
Except that they'd need a separate sticker for each location/utility in the country and they'd be obsolete within months.
Re:It's all BS (Score:5, Informative)
Most people argue GPM is better for exactly those reasons - it's easier to compare. For example, you have two cars - one that gets 10 mpg and one that gets 33 mpg. You can replace the 10 mpg with one that gets 11 mpg, or replace the 33 mpg car with one that gets 45 mpg. Quick, which saves more gas?:
A) replace the 10 mpg with 11 mpg
B) replace the 33 mpg with 45 mpg
The answer is A. The first changes from 10 gallons per 100 miles to 9 gallons per 100 miles - 1 gallon saved every hundred miles. Option B changes from 3 gallons per 100 miles to 2.2 gallons per 100 miles - less than a gallon saved (per 100 miles). It's completely non-intuitive if you use the backwards "mpg" measurement.
If we just used consumption instead of MPG, we wouldn't have this problem. [mpgillusion.com]
Re:It's all BS (Score:3, Informative)
I have to call BS on that. Yes, there is a bigger increase with A, but the only time this matters at all is if I have 2 vehicles in need of replacement at the same time, money for only one of them, and no pressing preference for utility between them; and then you would have to figure out which you drive more often to get a reasonable determination of which to get.
In reality, it works like this: you have a 20 mpg car in need of replacement. You can replace it with a 25 mpg car, or a 32 mpg car. Quick, which saves more gas?:
A) Replace the 20 mpg with 25 mpg
B) Replace the 20 mpg with 32 mpg.
For direct comparison of savings coming from two completely different situations, yes, gal/100 miles is better. But the combination of events and requirements needed for such a comparison to be at all useful is completely absurd. For nearly all situations the "which number is bigger" method of determining mileage superiority is perfectly adequate.
Re:Giant letter? (Score:4, Informative)
That's weird, because the label they show in TFA is clearly for an electric car, and it lists the following figures:
kW-hrs/100 miles, MPGe city, MPGe highway
As I'm sure you're well aware, kW-hr/100 mi is not a rating in miles per gallon. The other two figures are miles per gallon equivalent and are to facilitate comparison across fuel types.
Re:I call BS.kg (Score:3, Informative)
You mean like the second label shown in TFA, which has a section (with a helpful little battery-shaped box to help you find it) that indicates the charge time?
Re:That IS bad (Score:1, Informative)
I think your math is off. 1GW/h = 1000MW/hr = 1,000,000KW/h .000391 or .04% of 1 hrs output of the plant. Or, phrased differently, one day's output of the plant would power
((23*50) / 100) * 34 = 391KW/h =
61,381 of the cars, for a distance of 1150miles each.
Re:Giant letter? (Score:5, Informative)
The sticker says "over five years, this vehicle saves $6,900 compared to average". The small print says that's based on 15000 miles/year, and an average of 20-23 mi/gal (21.5mi/gal = 4.65 gal/100mi).
Presumably, your Ford Ranger would have had a sticker like "over five years, this vehicle costs $5,200 more than average" (based on your 14mi/gal (7.14gal/100mi) figure, and $2.78/gal). Would that have influenced your decision? You can rent something that hauls heavy loads many times for $5,200, for example. (And presumably insurance, parts etc cost more on the bigger and more powerful car).
(FWIW, with fuel costs here the $5,200 would become $12,306. You could buy a small car [fiat.co.uk] with the saving... and since that one uses 47mi/gal (2.12gal/100mi) you'd save $5300 (or $12500 here) compared to average [I know US gallons are different to the Imperial gallons given on that page, I converted them for you.]).
Re:I call BS.kg (Score:4, Informative)