Your car is now getting fewer miles per gallon

Yesterday the EPA announced that, starting sometime next year, the sticker on new cars will show how many miles per gallon the car will get in real-world driving, not based on lab tests, which can inflate the mileage by as much as 50 percent.

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Currently, EPA relies on data from two lab tests for the city and highway estimates. They're done in mild conditions, at 75 degrees Fahrenheit, using top highway speeds of 60 mph and average speeds of 48 mph. Those conditions, EPA acknowledges, are "generally lower than those experienced by drivers in the real world."

[...]Automakers starting in 2011 would have to perform extra driving tests to reflect high-speed driving, rapid acceleration, use of air conditioning and cold weather not now part of the agency's laboratory tests.

Interestingly enough, the new ratings only affect the stickers on the cars, not the bigger picture:

The new, lower ratings, however, will not be used to gauge compliance with government regulations requiring automakers to produce fleets averaging at least 27.5 mpg for cars and 21 mpg for light trucks.

How this system, called the Corporate Average Fuel Economy program, works is that automakers' fleets of cars must average out to these mileage levels. So for each formerly-50mpg Prius that Toyota makes (which in reality get closer to 45 mpg for a tank of gas, and which under the new ratings will likely be bumped down to 35 mpg), the company can produce a couple of 15-mpg Highlanders.

Under the new ratings, does that mean we'll be seeing a lot more fuel-friendly vehicles on the road? Not likely. Not likely at all. Instead, if an AP report from Monday is accurate, Detroit will flood the Farm Belt with more ethanol-fueled cars.

A federal push for cars that run on an alternative fuel straight from the heartland isn't winning many converts among American drivers -- but is a hit with automakers who use it to skirt mileage standards.

Five million cars across the country are equipped to run on the fuel, but almost no one uses it outside the corn belt.

Fortunately for carmakers, a 1988 law designed to decrease oil use gives them credits for building vehicles that run on the alternative fuel whether anyone uses it or not. Those credits allow automakers to relax gasoline efficiency standards on other vehicles -- which drives oil consumption up instead of down.

So automakers get to use these ethanol vehicles to balloon their average fuel mileage, and thus continue flooding the market with heavy, oversized gas guzzlers that they believe the public wants. Big surprise they support the program so much: