Mazda's diesel-powered mid-size has been delayed.

Mazda's diesel-powered Mazda6 mid-size sedan won't arrive in the United States until April of 2014, the Japanese automaker has revealed. The project is being delayed due to set backs in emissions testing.

Mazda's Skyactiv-D-powered Mazda6 was originally slated to arrive in dealer showrooms before the end of 2013, but Robert Davis, senior vice president of U.S. operations for Mazda North American Operations, confirmed in a letter to employees that the car's launch has been pushed back until next spring. That letter was obtained by Automotive News.

After the contents of Davis' letter began to circulate, Mazda issued a statement saying the Mazda6 Skyactiv-D turbodiesel had been delayed "to accommodate final emissions testing and certification."

"I know we had discussed it being in showrooms before the end of the year, and everyone involved in the program is disappointed it will not be, but final certification testing -- the results of which are looking encouraging -- is taking longer than we had initially expected," Davis wrote.

When it does finally launch during the first half of next year, the Mazda6 Skyactiv-D is expected to boast a 2.2L four-cylinder engine with about 173 horsepower and 310 lb-ft of torque. The Mazda6 diesel will be the first diesel-powered mid-size offering from a Japanese automaker and will go head-to-head with the Volkswagen Passat TDI.

Photo by Mark Elias.