2008 Mercedes-Benz E320 Bluetec

As I steamed up an on-ramp in the newest E320 Bluetec, my friend asked, "Wow-this thing got a turbo?" There were four aboard, and he was impressed by the tug at his insides. "Yup," I replied, "bolted to a six-cylinder diesel engine." Such was his disbelief that he got out and checked the badge on the car at the first stoplight. "How come it doesn't smoke, then?" Welcome to 2008 diesel technology. And 1978 diesel perception.

The new 50-state version of Mercedes's 3.2-liter turbodiesel Bluetec V-6 uses urea solution injection technology, called AdBlue, to meet even California's tough emissions standards. The ammonia-based fluid reduces nitrogen-oxide levels to the point that the diesel is as clean as the E350's 3.5-liter gasoline V-6. Bluetec is currently available in the E-Class and will be offered in the M, R, and GL-Class SUVs later this year.

Its 208 horsepower won't impress anyone, but it's the 400 pound-feet of torque, served from between 1600 and 2400 rpm, that will. There's a bit of turbo lag off the line, but drive the E320 within that huge torque band, and you'll leave others standing agog. Its midrange passing power is phenomenal, and the seven-speed automatic trans offers a ratio for every occasion.

The rest of the package is standard-issue E-Class, but what's with the puny 16-inch wheels? They look dated and positively silly on a car this size. Mercedes offers AMG 18-inchers on other E-Classes-but not the Bluetec. Does the company think diesel owners don't want crisp handling and sporty looks, too?

Our other issue is economic. Based on the E320's six-mpg EPA city advantage over the E350, and factoring in a current cost premium of around 40c per gallon, the diesel saves about $2000 over 50,000 miles of city driving. And it costs $1000 more than the gas model. So the sparkle of better fuel economy is mitigated on its way to your wallet.

Still, less fuel burned means a smaller carbon footprint. Bringing this technology to market here will pay off in the long run for Mercedes-Benz. In-the-know types who want them will love the way they drive. Especially when facing an on-ramp.