NEW YORK –- While about 7.5 million cars with diesel engines are sold in Europe each year, fewer than 50,000 are sold in the U.S. According to Forbes’ Backseat Driver columnist Jerry Flint, U.S. manufacturers may have the chance to gain ground in the at a time when fuel costs are high and cleaner diesel fuel is becoming more widely available, but many barriers stand in the way. In Europe, governments do not tax diesel fuel as much as gasoline, and because diesel cars already get 25- to 30-percent better mileage than gasoline-powered vehicles, the advantage is two-fold. Flint also notes that although diesels cost more to build, European manufacturers hold down the prices of diesel cars to boost sales, resulting in diesel cars comprising half of new car sales annually in Europe. In the U.S., diesel does not currently have a price advantage over gasoline. In addition, General Motors, Ford Motor Co. and Chrysler would all face overhauling their engine factories to make the switch to diesel. Other manufacturers such as Mercedes and Volkswagen offer or are planning to offer some diesel models, but stricter federal emissions standards will force some to pull models off the market, further slowing diesel sales. Although new technologies promise to reduce the smell, noise, particulate emissions and slow winter warm-up of diesels, interest in hybrid and other technologies may prevail over diesel in America.