LOS ANGELES – With the 2008 model-year getting underway in earnest, significant numbers of car buyers will get their first look at the government’s new fuel economy ratings, according to the Los Angeles Times.

The Environmental Protection Agency (EPA) said last year that it would begin using tests that better reflected real-world driving conditions, which will likely result in lower estimated mileage numbers. Hybrids and other high-mileage cars will take the biggest hits.

Although the 2008 Toyota Prius isn’t in showrooms yet, the EPA back-tested several years’ worth of cars using a mathematical formula based on the new testing methods, the Times said. Based on the new test, the combined city-highway mileage for the 2007 Prius dropped from 55 miles per gallon to 46, a 16-percent decline. The Honda Civic hybrid, also a 2007 model, showed a similar decline.

Drivers have long complained that the EPA’s mileage test, developed in the mid-70s, didn’t take into account the way people actually drive. For instance, the test didn’t measure the effects of stop-and-go driving and lead-footing on fuel economy.

In addition, according to the Times, the national speed limit was 55 mph when the old test was developed. Today, it’s as high as 80 mph in some places.

In 2005, Consumer Reports tested 303 cars and trucks and found that about 90 percent got lower mileage than the EPA’s estimates. The mileage for city driving averaged about 30 percent below the government’s figures.

Besides listing mpg estimates, the EPA’s new window stickers will also compare a vehicle’s fuel economy with others in its class, and give a more precise breakdown of how the annual operating cost figure is calculated.

To browse the new mileage estimates, and compare them with the EPA’s old numbers, visit: www.fueleconomy.gov. To see the new window sticker, go to www.epa.gov/fuel_economy/label.htm.

Originally posted on Fleet Financials