Feast your eyes on this, car technology and high-mileage nuts. It's a Honda Accord that runs on diesel.

Honda expects to bring the clean-diesel car to the U.S. by 2010. It gets 62.8 miles a gallon on the highway, but otherwise looks and feels like a regular Accord. At that mileage level, the car is about as "clean" as a new Toyota Prius. But if you run it on biodiesel, a form of diesel made from vegetable oil or animal fat, it would be even cleaner than a Prius (Priuses get 60 in the city).

The advantage of diesel cars, however, is that they pack a lot of power.

Courtesy Diesel Technology Forum

The car was shown off with a number of other cars in Sacramento, Calif., earlier this month as a way to promote clean diesel cars and technology. In the '90s, California passed strict emission controls that restricted the amount of sulfur a car could emit. As a result, diesel manufacturers curbed sales to California and the U.S. in general.

Since then, petroleum manufacturers have devised cleaner diesels that only emit about 15 parts per million of diesel, down from hundreds of parts per million. That satisfies the California law. Manufacturers, meanwhile, have come out with more efficient and powerful diesel engines that get 20 to 40 percent better mileage than their older cars.

"A lot of changes have taken place in the engine, all thanks to electronics," said Allen Schaeffer, executive director of the Diesel Technology Forum, which helped organize the Clean Diesel Technology Tour. (Cars from Audi and a tractor trailer rig from Caterpillar were also shown). "Half the cars in Europe are diesel."

Thus, diesels, usually thought of as smelly, are now environmentally somewhat sound.