2012 Mercedes-Benz SLK 250 CDI - Frankfurt Auto Show

When Rudolf Diesel first conceived his compression ignition engine, it's doubtful he envisioned it in anything similar to today's modern automobile. And if, more than a century later, he might have imagined it in personal transport, it's unlikely he would have seen that transport as being quite so personal as the Mercedes-Benz SLK 250. But there, on the Mercedes-Benz stand in Frankfurt, is Mercedes' newest roadster, powered by Rudy's 19th century concept.

Of course, we all have our idea of what a modern roadster should be, and the recipe typically includes low curb weight, precise handling and prodigious power. The SLK, while relatively light in the context of the Mercedes lineup, isn't a Miata, and its handling is closer to that of Grand Tourer than minimalistic sportster. That said, with the steps taken over the last decade (by Mercedes and many others) to make the diesel both more engaging and efficient, the diesel-powered SLK doesn't demand the mechanical (or psychological) leap it might have required ten years ago.

With a displacement of almost 2.2 liters, the SLK diesel generates 204 horsepower and almost 370 lb-ft of torque, making the SLK CDI the most powerful diesel model in its class (although we suspect it's a very small class). At launch the SLK CDI will be available with a 7G-Tronic Plus automatic; a 6-speed manual will follow in the second quarter of 2012. From a stop, 0-62 arrives in under seven seconds, and the fresh air diesel will top out at an even 150 mph. And the good vibe doesn't stop there, as the diesel delivers amazing flexibility, along with almost 50 miles per gallon in highway driving.

Mercedes, of course, touts the total package. And we were intrigued by the SLK CDI's suggested capability: Driving from the North Sea to the Mediterranean non-stop. We think Rudy would have liked that.


See more coverage of the 2011 Frankfurt Auto Show.


DAVID BOLDT began his automotive career in BMW and Saab showrooms in the 1980s, and he moved to automotive journalism in 1993. David has written for a variety of regional and national publications, and prior to joining AutoTrader, he managed media relations for a Japanese OEM.