EPA Revised Fuel Economy Figures Go Down

What’s going on is an attempt by the Environmental Protection Agency to bring a little real-world data to the business of calculating fuel economy. For years, the EPA has relied on a test originally developed during the energy-crisis days of the early 1970s, and most recently revised in 1984 (when, even then, their numbers were being criticized for being higher than what average driving would produce).

The test, as it currently stands for the 2007 model year, produces accurate numbers—if all you do is run your car on a treadmill without air conditioning, it would seem. Yes, the EPA test is run without A/C; the new 2008 test will include it for the first time. It also includes some acceleration routines, except that they are carried out by the proverbial Little Old Lady from Pasadena: Look, 0 to 60 in 19 seconds (which is what 3.2 mph per second equates to). Next year’s test will up that to 8 mph per second, which is more realistic.

Also changing in next year’s test is the simulation of cold-weather driving (previously, a constant temperature was used), and a maximum top speed of 80 mph, instead of 60 mph.

Because of all of these changes to the test, the EPA calculates that people should see a reduction, on average, of 12% in city mileage, and 8% in highway mileage. However, on some cars, there could be as much as a 30% drop.

One EPA spokesperson said this should give incentives to automakers to optimize their engines for real-world conditions, such as finding ways to reduce gasoline consumption when the air conditioner is running.

Some manufacturers, such as Toyota, contend that the EPA should really emphasize another number that’s on the fuel-economy sticker—in small type—but which doesn’t get talked about much: the annual fuel cost, rather than the specific miles-per-gallon of the vehicle. After all, they contend, the car’s owner is not paying for “miles per gallon”; they’re paying based on the cost of the amount of fuel that the car uses, and that should be what we base our fuel-economy metric on.

In fact, looking at the consumption figure can be revealing; if you were to compare a compact car getting 40 mpg and an SUV getting 12 mpg, and then lower their fuel economy figure 20% for the small car (to 32 mpg) and 10% for the SUV (to 10.8 mpg), you’d think that the small car would suffer the most in this downgrading. However, run the numbers: figuring an average fuel price, and saying that the cars will be driven 15,000 miles a year, you would discover that the small car would actually come out ahead; the original set of fuel-economy figures would yield the fact that the SUV would use 875 gallons more than the compact car, whereas the new figures show that the SUV would use 920 gallons more than the small car. Advantage? Small car, to the tune of 45 gallons a year.

Our take? We’ve heard the phrase for so long, that “your mileage may vary” has entered the popular lexicon. But it is true—how you drive affects the amount of gas you consume. Drive like Lead-Foot Larry, and your engine will drink gas like a fish; drive in a smoother, slower manner, and you’ll save on fuel (ask any hybrid owner—many of them play endlessly with their dashboard computer to eke out the maximum mileage possible). We’re glad to see the EPA inject some real-world sensibility into their mileage testing, for once. It may not be super-accurate for everyone, but it does come closer to what the average buyer can expect from their new car.

Via: The Wall Street Journal