DETROIT -- Everybody's doing their part for the environment, even Ferrari, maker of cars getting 9-17 mpg. At this week's North American International Auto Show in Detroit, Ferrari said it, too, may offer cars than can run on E85 fuel, or "bio fuel," as the logo said on the side of a Ferrari F430 Spider (11 mpg city, 16 mpg highway, $173,000-$234,000 with a long waiting list) on the display at Detroit's North American International Auto Show. Also called Flex Fuel, E85 is a mixture of 85% ethanol, 15% gasoline that reduces emissions and raises horsepower (by 10, to 490 hp, in case a Ferrari needs more). But it also lowers gas mileage, by 5%-15% (the official line), perhaps by 25% (tests by USA Today). Bio fuel is all part of Ferrari's goal of cutting emissions by 40% by 2012. One small problem if this comes to pass: Ferrari sells cars where E85 doesn't sell. In the U.S., E85 is a heartland America product while Ferrari sells best along the coasts. California alone takes 10% of Ferrari's annual output of 6,400 cars. Ethanol fuels are also common in Central and South America, but there Ferrari sells less than 100 vehicles year.