The European version of the car, which is manufactured by Smart, a subsidiary of Mercedes-Benz, is rated to get 60 miles per gallon. However, Campbell said that after being modified by G&K Automotive Conversions to meet the tougher U.S. emissions standards, the car received an initial Environmental Protection Agency rating of just 37 mpg... In its current form, the Smart could be sold in 45 states, but not in California and four others that adhere to the nation's toughest emissions standards.
"In Europe, when people think clean, they focus on global warming and that is carbon dioxide, which is fuel economy," says John Koszewnik, director of diesel engines at Ford Motor Co. "And there, diesels have a 30 to 40 percent advantage. In the U.S., the clean thought is led by California, and there, they're not so worried about global warming. The C02 they produce goes over the mountain. They're worried about NOx."