Americans remember the diesel engine as a sluggish, clattering performer that filled the air with clouds of sooty exhaust smoke. But with the introduction of Mercedes-Benz Bluetec technology at the 2006 North American International Auto Show in Detroit, this German automaker is proving that modern diesels are clean, strong, and refined engines that save fuel with no loss of performance, or air quality.

Mercedes-Benz was the first automaker to incorporate diesel technology in a passenger car some 70 years ago, so it comes as no surprise that this German company is now the first to create a turbodiesel engine for use in passenger vehicles that will meet the strictest emissions regulations around the world.

Bluetec arrives first under the hood of the 2007 Mercedes E-Class, but will be added to the company’s three SUVs shortly thereafter. In Detroit, the Mercedes Vision GL320 Bluetec Concept shows that, in addition to the M-Class and R-Class, the new GL-Class will also get a strong, clean-burning, fuel-efficient turbodiesel engine option. The production version of the Mercedes-Benz Vision GL320 Bluetec will combine seven-passenger seating with 83 cubic feet of cargo space, a 25-mpg highway fuel economy rating, and the torque of a V8 engine in what Mercedes says will be the most economical full-size SUV on the market. In our book, this is a mid-size SUV, but whatever – Ed. The bigger news is that when the GL320 Bluetec hits the road, it will do so in California and New England, regions of the U.S. that are currently verboten to turbodiesel engines in passenger cars.

Editor’s Note:If you want to know how Bluetec technology makes a turbodiesel engine clean, read on. Otherwise, you’ll get bored, so skip to the end.

Diesel fuel sold in the United States contains large amounts of sulfur, and this sulfur content, among other factors, is what causes a diesel engine to run dirty with nitrous-oxide emissions. With Bluetec technology, emissions are reduced through the use of an oxidizing catalytic converter, a particulate filter, and what Mercedes calls a DeNOx nitrogen-oxide reducing system. DeNOx is the key here, a storage catalytic converter designed to treat engine exhaust gases before they are emitted from the tailpipe, and it reduces nitrogen-oxides by up to 80 percent. A reducing agent called AdBlue is injected into the gases contained in the storage catalytic converter, releasing ammonia which converts the nitrogen oxides into harmless nitrogen. The separate tank that stores the AdBlue is refilled whenever the car returns to the dealer for service.

To work properly, Bluetec technology requires the use of low-sulfur diesel fuel, defined as that with a sulfur content below 15 parts per million. This type of fuel will be available in the U.S. starting in the fall of 2006, at the same time the first Bluetec vehicles go on sale, but may not be widely available. Over time, however, the fuel will become the standard in North America, and DaimlerChrysler will be ready to capitalize on this with a fleet of Bluetec-equipped cars and SUVs wearing Chrysler, Dodge, Jeep, and Mercedes-Benz badges.

Designed to meet upcoming 2009 emissions regulations and beyond, Bluetec is no temporary fix. In Europe, where half of all new vehicle buyers choose a diesel model, more than 10,000 heavy-duty trucks already use Bluetec. Plus, Mercedes-Benz plans to connect Bluetec diesels to hybrid drive systems to create even cleaner, greener, and more efficient vehicles in the future. Clearly, DaimlerChrysler thinks that diesel will power tomorrow’s cars in greater numbers, and Bluetec will be the instrument it uses to ensure success.

Photos by Ron Perry