Drivers in Europe have been reaping the benefits of a wide selection of diesel cars for years, but with the fuel set to become more popular in the U.S. too, many carmakers are expanding their range of diesel vehicles.

Mazda is one of those carmakers, with the next generation Mazda6 and the 2013 Mazda CX-5 crossover both expected to gain diesel engines.

That diesel is Mazda's new-generation SKYACTIV-D unit. In Europe, this 2.2-liter, four-cylinder turbocharged diesel produces around 150 horsepower.

When even the gasoline SKYACTIV CX-5 gets 35 mpg highway, the figures for the diesel could look quite impressive indeed--and even more so in the sleeker next-generation Mazda6.

The next Mazda6 will take its inspiration from the Takeri concept shown at the 2011 Tokyo Auto Show, and Mazda promises the car will be lighter than the current model. If it's more aerodynamic too, that bodes well for impressive economy figures with the SKYACTIV-D engine.

Autoguide says the car is already being previewed to dealerships, and the diesel is expected to land some time around October 2013. In addition to the diesel, the 2014 Mazda6 is expected to debut with a 2.5-liter SKYACTIV-G gasoline engine, when the model hits the market in March 2013.

The real question is which Mazda will get the diesel unit first. The CX-5 might seem the natural choice, given that it's already on sale--but Mazda could wait to introduce it with the strikingly-styled next generation Mazda6. It would also provide Mazda with a natural rival to the 2014 Chevrolet Cruze diesel, expected around the same time.

For more information on diesel cars on sale and about to hit the market, check out our guide to every 2012 and 2013 diesel car on sale in the U.S.

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