Mercedes brings back diesel power to U.S. with new 2005 E320 CDI

By Jim Meachen and Ted Biederman

A veteran journalist, who has been an automotive writer on a number of national publications for the better part of a half-century, was emphatic: “Diesel is the future,” she said, during a discussion while returning to the airport.
We had previewed a new hybrid vehicle on the West Coast the day before and talk during the half-hour ride turned to the impending gas crisis facing our nation and the high cost of fuel.

We agreed that diesel engines are the simple solution to our gas mileage miseries. The hybrid vehicle we had just road tested is okay, she said, but hybrids are not living up to their gas mileage claims (they do better on dynameters then in the real world), there are too many components and what eventually happens to the batteries?

Diesel engines have been around for 100 years and vastly cleaner-burning highly efficient diesel engines are here now and available in cars and light trucks, albeit in limited numbers in the United States.

In Europe where the cost of fuel is two and three times the cost in North America, diesel engines make up about 40 percent of the mix.

For too many years people have associated diesel with dirty, smelly and noisy big-rig trucks. This stereotype gives modern diesel cars a bad and certainly undeserved rap. It is now possible to build a diesel engine virtually free of all the traditional diesel traits including clattering noise and diesel smell.

Mercedes-Benz has accomplished this feat.

We just spent a week behind the wheel of the 2005 E320 CDI inline 6 that possesses more off-the-line power than the corresponding Mercedes 6-cylinder gas engine in a way that is so unobtrusive that you don’t realize you are driving a diesel. It is the most advanced diesel technology currently available.

The downside to Mercedes’ new technology is that it’s not built for the masses with a starting price of $49,795.

A diesel has two distinct advantages over a gas engine. It gets considerably better fuel mileage and it produces prodigious amounts of torque over a wide rev band.

The diesel engine, developed by Rudolf Diesel in 1892, differs from a gas engine in that diesel fuel is injected directly into the cylinder. Diesels are more efficient than gas engines because diesels compress air two or three times more densely in their cylinders. That results in more powerful explosions inside the cylinders while using smaller amounts of fuel.

The injector on a diesel engine is its most complex part, and the Mercedes diesel engine uses common-rail direct injection together with variable nozzle turbine turbocharging.

Suffice it to say the result is fascinating.

One of the criticisms through the years is that diesel engines are polluters. But low sulfur diesel fuel, mandated for all areas of the United States by 2007, and new engine technology should reduce diesel emissions to the level of gas engines.

And in fact, the government has mandated that by 2007, diesel engines must meet the same emissions guidelines as gasoline engines.

The new-generation Mercedes engine meets current standards in all states but California, New York, Maine, Massachusetts and Vermont. There too, new rules will allow diesels at least in the 2007/2008 timeframe.

While the new engine in the 320 CDI develops only 201 horsepower compared to the gas engine’s 221, it is actually faster from 0 to 60 because of its massive torque rated at 369 pound-feet. Torque is what moves a vehicle from rest and the Mercedes is capable of leaping from a resting position to 60-mph in 6.8 seconds. And the torque band is so accessible that firm pressure on the gas pedal at virtually any speed results in a leap to life.

The 320 CDI has all the amenities of other E-Class models. That is to say, it is one of the most quiet and comfortable mid-sized sedans on the planet.

The E-Class was completely redesigned for the 2003 model year. Mercedes streamlined the 1996 design, which was a radical departure from earlier E-Class models, while keeping the overall theme intact.

In other words, the oval headlights and Mercedes grille are still there, but in a more modern rendition. The signature headlights are more oval and more at a slant blending into the front fenders.

The E-Class is more wedge-shaped than the previous edition giving it a sports sedan persona. The entire package is handsome in an elegant, conservative fashion.

Mercedes leaves no doubt that you are riding in the lap of luxury. The doors thunk when shut, and leather and wood are scrumptious, familiar landmarks for those accustomed to products from the German automaker.

A host of good stuff is standard equipment including the electronic braking with brake assist, Electronic Stability Program  (anti-skid control), front and rear side airbags and head-protection curtains, power adjustable tilt and telescoping steering wheel, dual-zone climate control, nine-speaker stereo system, and leather upholstery and wood trim. 
 The interior is a marvelous work of art. The sculptured cockpit sweeps in and then out through the center console and then back in through the passenger compartment. Surfaces constructed of soft-touch polyurethane skin sprayed onto the base material offer a luxurious feel and a quality appearance.

Controls are generally easy to learn, although someone unfamiliar with the layout of the stereo setup is advised to spend an evening pouring over the owner’s manual.

Unfathomable as it seems, Mercedes includes only a single-disc in-dash CD changer as standard equipment. Cars costing a third as much have 6-disc changers available.

And at this point we must make note again of Mercedes’ flimsy cupholders, which unfold from the center console. And we discovered they don’t hold a large drink from a fast food restaurant.
Also, Mercedes continues to place the turn signal/wiper stalk next to the cruise control stalk on the left side of the wheel. It can be annoying. We hit the cruise stalk more often than not.

Diesels used to be a staple of Mercedes. In fact, back in the ‘70s and ‘80s about 80- percent of all Mercedes products were diesel powered.

That ended in 1999 when Mercedes abandoned diesels in the U.S.

The Mercedes diesel is back and after a week behind the wheel we hope it stays, even as emissions requirements get tighter. Mercedes owners will be the winner, especially at the gas pump.

And to cap all this talk off, Popular Science magazine has just given Mercedes a “Best of What’s New” award for the E320 CDI in its upcoming December 2004 edition. And they know their stuff.