DETROIT – For the first time in 20 years, the Environmental Protection Agency (EPA) has unveiled a proposal to change the way it calculates fuel economy ratings for cars and trucks so that automobile window stickers reflect real-world driving, according to the New York Times. Fuel economy estimates currently take into account only how vehicles perform, on average, under city driving conditions and on the highway. The new estimates will use much more information to make the calculations. For example, the EPA will now use data from tests representing real-world, conditions. These include driving at high speeds and with rapid acceleration, when air conditioning is in use, in cold temperatures, on steeply graded roads, and in windy conditions, as well as taking into account whether tires are properly inflated and what kind of fuel that is in the gas tank. As a result of these new ratings, the fuel economy estimates for city driving would drop by 10 to 20 percent, while fuel economy estimates for highway driving would fall by 5 to 15 percent. The EPA estimates that fuel economy for hybrids would result in a 20 to 30 percent drop, although estimates for highway driving would drop the same 5 to 15 percent as gasoline-powered automobiles. If adopted, the proposal will take effect beginning with vehicles built for the 2008-model year, which go on sale in 2007. The EPA will take comments from the public, the industry, and other groups on the changes for the next 60 days. Also set to change, if the proposal is adopted, is the appearance of window stickers themselves. The agency is considering four different designs for the stickers and is expected to choose one later, according to the Times report.