2007 Mercedes-Benz E-Class Sedan Test Drive

Blue Is the New Green

With the E320 Bluetec, Mercedes-Benz delivers the most fuel efficient luxury car on the American market.

For Mercedes-Benz owners interested in not settling for less (i.e., all of them), there’s the E320 Bluetec, an E-Class sedan that looks and drives like the standard V6 model while delivering well over 30 mpg, enough to save the typical owner about $500 a year in fuel costs. The car can travel more than 700 highway miles on a single tank. In a way, since it delivers better fuel economy and range, E320 Bluetec owners actually settle for more.

For luxury buyers who care about conservation or cutting fuel bills, the Mercedes-Benz E320 Bluetec is simply unmatched. In our test, it achieved the mileage of a small car with a four-cylinder engine, and did so without skimping on the performance, comfort and features you expect from a Mercedes sedan.

The E320 Bluetec can achieve these feats because it has a diesel V6 engine.

Forget what you know about diesels: the chugging sound; the sooty, smelly exhaust; the lazy acceleration. The Mercedes E320 Bluetec is powered by a modern “clean diesel,” the kind found in more than half of the new cars sold in Europe. Thanks to a turbocharger and high-pressure fuel injection, the car is fast, quiet, refined and completely odor-free.

Strict federal exhaust emissions standards and the public’s outdated views of diesel technology have kept these vehicles from becoming as popular in the U.S. as they are in Europe. But a type of diesel fuel called ultra-low sulfur diesel has been a pivotal break in the barrier to wider adoption of diesel vehicles. This new diesel fuel has 97 percent less sulfur content — sulfur is one of the most problematic and toxic byproducts of diesel combustion and is often cited as a significant contributor to acid rain.

Environmentalists and regulators have hailed this federally mandated diesel fuel as the most important clean-air development since the removal of lead from gasoline in the ‘70s. It became available in the U.S. in October 2006.

The main thing buyers need to know about this is that the low-sulfur diesel fuel clears the way for new pollution-fighting technology that should make diesel engines nearly as clean as the best gasoline cars — just in time to meet new emissions rules, the world’s strictest, coming in 2009. With that, many major automakers, including Audi, BMW, Ford, General Motors, Honda, Nissan and Volkswagen, have announced their own clean diesel models coming to showrooms between 2008 and 2010.

But before you race to the Mercedes dealership for your Bluetec, check the map: The car can’t be sold in California, Maine, Massachusetts, New York or Vermont because those states have stricter emissions regulations. However, for 2008, Mercedes has unveiled a urea injection system to convert smog-forming nitrogen oxides into harmless nitrogen and water. The small tank will be refilled with urea roughly every 15,000 miles as part of scheduled maintenance. Clearing that last pollution hurdle will allow several Mercedes diesel vehicles to meet the toughest pollution standards and be sold nationwide.