Mercedes has been talking about a diesel GLK and C-Class in the U.S. since at least 2008. There's even the possibility they'll be built in the company's Alabama plant. The timeline has largely been aimed at 2012-2013 for U.S. construction and sale, though before the market crash of 2008, there were plans to have oil burners in the GLK and C-Class by 2010.

The latest reports don't do much to change that timeline, but they do confirm the idea is still gestating.

So what would a diesel C-Class or GLK look like? Like any other example of their model, of course, except for the 250-badged 2.1-liter turbodiesel under the hood. The C250 BlueTec and GLK250 BlueTec, when they arrive, will share the same engine, turning out 204 horsepower and 369 pound-feet of torque.

For a very good preview of what to expect, one need look no further than the E250 BlueTec concept shown at last year's New York Auto Show. That model was powered by a 2.2-liter engine, though it's anyone's guess if Mercedes was just rounding the displacement up as they are wont to do. On the other hand, previous reports have tipped a 2.2-liter engine rated at 167 horsepower and 295 pound-feet of torque, which while a little wimpy, would certainly nail the CAFE targets that are likely driving the diesel decision.

Mercedes isn't the only German carmaker with possible new diesel models for the U.S.: Porsche is mulling plans to boost the number of diesels it sells here, too.

[Car and Driver]