This year, 2014, is going to be the big test for diesel engines in U.S. passenger vehicles.

It's the first full year in which two popular cars--the Chevrolet Cruze compact sedan and the Jeep Grand Cherokee--are offered with diesel engines as optional equipment, complete with higher EPA fuel efficiency ratings.

MORE: Volkswagen Jetta TDI: Much More Mileage Than EPA Admits?

And they're joined by additional diesel vehicles, too, among them the Audi Q5 TDI and Mercedes-Benz GLK 250 BlueTEC, both luxury compact crossovers.

2014 Chevrolet Cruze Clean Turbo Diesel, 2013 Chicago Auto Show

2014 Chevrolet Cruze Clean Turbo Diesel, 2013 Chicago Auto Show

Chrysler refuses to say how many Grand Cherokee EcoDiesel models it sold last year, but GM was more open about sales of the 2014 Chevrolet Cruze Diesel, its first diesel passenger car since 1986.

Chevy delivered 3,028 Cruze Diesel models--with a price starting at $24,000--from May through December 31. That's about 1.2 percent of the total 248,224 Cruzes sold in 2013.

The Volkswagen Jetta TDI, also a diesel compact sedan, sold 26,587 units in 2013, as diesel sales by Volkswagen Group brands exceeded 100,000 units for the first time. That represents almost one out of every five Jetta sedans sold in the U.S.

Meanwhile, the Chevrolet Volt range-extended electric car logged 23,094 sales last year, more than seven times the volume of the diesel Cruze--at a 2014 base price $11,000 higher.

MORE: FINAL UPDATE: Plug-In Electric Car Sales For 2013 Near Double Previous Year's

It's important to note that the first diesel Cruze was sold only this past May, and the car initially rolled out in only 13 diesel-friendly regions. So the 2013 sales total does not represent a full year's potential sales.

With the diesel Cruze more widely available, and a growing awareness that diesels offer better fuel economy numbers--especially in highway use, where they often exceed their EPA ratings--this year should provide an interesting test of the market appeal for plug-in electric and diesel alternatives.

Do you think the Cruze Diesel can equal sales of the plug-in Chevy Volt?

Leave us your thoughts in the Comments below.


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