Already I’m starting to see it: people around the Internet are criticizing 2008 models for low EPA ratings. What they’re forgetting is that the EPA has revised the methods used to calculate fuel economy ratings for 2008 model year vehicles to make the numbers more realistic.

The new method includes data from tests that include more rapid acceleration, higher highway speeds, colder outside temperatures, and running the air conditioner (details here). The net effect is that EPA city ratings will be declining by two to three miles-per-gallon and EPA highway ratings will be declining by one to two miles-per-gallon.

These changes don’t sound like much, but what they mean is that many cars that used to have an EPA city number in the high teens will now have an EPA city number in the mid-teens. And we’ve become used to thinking of a mid-teens number as bad.

I nearly made this mistake myself when driving a 2008 Dodge Avenger R/T a couple weeks ago. I walked up to the car, noticed the EPA city rating of 16 (and a highway rating of 26), and was shocked that the car was such a guzzler. Then I remembered the change. The same car using the old methods would have been rated 19/28, typical for a mid-size sedan with a powerful V6.