2007 Mercedes E320 Bluetec
 

While Toyota??s Lexus division aggressively has pushed the idea that gasoline/electric hybrids are the future for the luxury market, Mercedes-Benz is rolling out another vision???diesel technology. And the first product in this assault is the E-320 Bluetec.

Yes, that??s right a very luxurious E-Class Mercedes sedan with a smelly, noisy diesel engine. Except that it is not smelly or noisy. And the kicker is that it gets terrific gasoline mileage, 37 mpg for highway driving with all of the acceleration and top speed that one would expect in a mainstream Mercedes-Benz luxury sedan.

Yes, it appears that the engine developed by Rudolf Diesel in the 1890s and the power source for most big trucks and ships will be getting another play in the automobile. Many readers will remember that Mercedes-Benz sold lots of diesel-powered automobiles during the 1980s as a response to fuel shortages. This attempt to popularize diesel technology was derailed by exhaust emissions and the fact that the diesel-powered cars of that era were both slow and noisy. But the fact that diesel power ultimately does deliver improved energy efficiency???20 percent to 40 percent???has kept the technology in the picture.

So, are diesel engines the power source of the future? It is surely too early to answer that question, but diesel will be getting a real play in the US and already holds a commanding market share in Europe. Observers have noted a decrease in automotive industry fascination with hybrid technology as witnessed by a paucity of new models at the 2007 Detroit auto show.

Mercedes-Benz is aggressively pushing diesel technology and has already announced that a diesel SUV will be a reality. Audi also has recently announced its own diesel-powered invasion of the US market. A new-generation 3.0-liter V6 diesel engine makes its U.S. debut in the E320 Bluetec. The Bluetec engine is not a warmed-over conventional gasoline power plant, General Motors tried that tack several years ago

and failed miserably. The Bluetec diesel is an all-new, ultra-modern 72-degree V-6 diesel with four valves per cylinder, dual overhead camshafts and centrally located piezo-electric fuel injectors. An engine-driven fuel pump is designed to spray diesel fuel directly into the center of the combustion chamber and each injector is precisely positioned in the aluminum cylinder head to ensure even dispersion of fuel as its flame front spreads concentrically across the combustion chamber. These injectors operate at an unbelievable 23,000 pounds per square inch of fuel pressure through the common-rail fuel loop. This design ensures clean and rapid fuel detonation.

In addition to engine technology, new fuel formulation is a key to clean diesel. What??s now called Ultra-low Sulfur Diesel (ULSD) is mandated by the US EPA to contain a maximum level of 15 parts per million. Such oil giants as Shell and Chevron now sell this fuel in many states. According to Shell, ULSD will be the dominant diesel fuel produced and eventually should be available nationally.

All of the above is cool technology, but what??s it like in real life. Fortunately, at this stage of development, diesel power as exemplified by the E320 Bluetec appears to offer no real deterrent to ownership assuming that the low-sulfur is readily available.

There is just a bit of the familiar diesel jingle-jangle upon start. But once underway that??s very little engine noise and in all other respects the Bluetec is just like any other E-Class sedan, ultra smooth and very luxurious. Acceleration is very comparable to other mid-market luxury

cars and the huge torque output ensures a big burst of speed for passing slower vehicles. Top speed is electronically limited to 130 mph, so there??s no performance disadvantage at all.

Source: [url=http://www.oakparkjournal.com/2007/2007-Mercedes-E320-Bluetec-Cordell-Koland.html]Oak Park Journal[/url]