2014 Mazda Mazda6
2014 Mazda6 (Mazda Motor of America Inc.)

Mazda’s diesel Mazda6 sedan, which the company originally planned to introduce to the American market this year, won’t be coming to the U.S. until April 2014, according to Automotive News. When released, the car will be the first in the U.S. to feature Mazda’s Skyactiv-D diesel engine.

In a statement quoted in USA Today, Mazda said “The on-sale date for Mazda6 Skyactiv-D clean-diesel has been moved to late-spring 2014, to accommodate final emissions testing and certification.” The diesel Mazda6 is already on sale in Europe and Japan, where demand for diesels (and the price of gasoline) is very high. However, emissions regulations are different there than in the U.S.

Diesels can offer much better fuel economy than gasoline engines. The gas-powered Volkswagen Jetta, for instance, delivers an EPA-estimated 24/34 mpg city/highway. The base diesel-powered Jetta delivers an EPA-estimated 30/42 mpg city/highway. The gas-powered Chevrolet Cruze gets 25/36 mpg city/highway and the diesel gets 27/46 mpg city/highway. Diesel SUVs have similar efficiency gains. The gasoline Jeep Grand Cherokee achieves 17/25 mpg city/highway; Jeep estimates that the soon-to-be-released diesel Grand Cherokee will achieve 21/30 mpg city/highway.

Diesels are becoming more popular in the U.S. The New York Times reports that sales of diesel cars and SUVs rose by almost 26 percent between 2011 and 2012.

Volkswagen in particular has found success with its TDI-branded line of diesel-engine cars. Forbes reports that diesel versions of the Jetta, Passat and Golf made up a record 24 percent of VW’s year-to-date U.S. sales through August.

Mazda would have been the only Japanese automaker to offer a diesel car in the U.S., according to Automotive News. Several German luxury carmakers, including Audi, Mercedes-Benz and BMW, already offer diesels in the U.S. American manufacturers, including Ford, Chrysler and GM, have sold diesel trucks for some time, and Chevy just began selling a diesel version of the Cruze.

In the market for a new diesel car? Check out the U.S. News rankings of this year's best cars. Then, look for a great deal on a new car by checking out this month’s best car deals. Also, be sure to follow us on Twitter and Facebook.