[font=Arial][size=4]Mercedes to drop Kompressor supercharger technology in favor of turbos
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[font=Arial][size=3]By JENS MEINERS | Automotive News Europe [/size][/font]


Mercedes will add a turbocharged 2.0-liter gasoline engine for the A Class subcompact that debuts in Europe this autumn.

"Turbochargers are superior to superchargers in terms of noise and cost," said Juergen Frey, head of engine development for the A class. "When we introduced the supercharged engines it was the right decision. Turbocharging has greatly improved in the meantime, and we have virtually no turbo lag anymore."

Mercedes plans to introduce an entry-level B Class model in the United States next year. It would be based on the A class, but it is not clear whether a turbocharged version will be available.

Jim Resnick, a spokesman for Mercedes-Benz USA LLC, declined to comment on the company's U.S. plans.

Turbochargers are cheaper than superchargers for gasoline engines. Turbos also generally deliver better fuel economy. That's why turbochargers are making a comeback in Europe. Teamed with smaller gasoline engines, turbochargers will help automakers meet stricter carbon dioxide emission rules that take effect in Europe in 2008.

The U.S. government has not imposed similar standards. But the California Air Resources Board has announced plans to limit carbon dioxide emissions, triggering a major battle with automakers.

Turbochargers and superchargers both pump mixtures of air and fuel into engine cylinders, substantially boosting power.

Both use rotary fan blades to drive the air-fuel mixture, but the blades are powered differently. Superchargers are mechanically driven, typically by a belt connected to the crankshaft. Turbochargers are driven by air pressure from the engine's exhaust.

Either device allows automakers to increase the power of small engines.

Many diesel engines are turbocharged, but virtually none are supercharged. On the gasoline side, Mercedes, Jaguar, Mini and General Motors offer a few supercharged models.

But automakers generally prefer to use turbochargers with gasoline engines.

Turbocharged gasoline engines became popular in the early 1980s, when Renault, Mitsubishi, Volvo and Saab adopted them. Their popularity faded because of high fuel consumption, lack of engine responsiveness and reliability problems.

Modern turbochargers have reduced the delayed throttle response of earlier models. Supplier Robert Bosch predicts that 40 percent of gasoline-powered cars sold in Europe will be turbocharged by 2008.

Mercedes and Maybach models equipped with V12 gasoline engines already use turbochargers. As Mercedes switches to turbochargers, it eventually will stop using the supercharged engines it markets under the name Kompressor.

Kompressor -- which means supercharger in German -- evokes memories of supercharged Mercedes cars in the 1920s and 1930s. In Europe, Mercedes currently offers superchargers on the 1.8-liter four-cylinder gasoline engine sold in the C and E classes, and on several AMG 5.5-liter V8 engines.

In the United States, Mercedes sells the C230 Kompressor Sport Coupe and the C230 Kompressor Sport Sedan. AMG will drop its supercharged V6 in the United States after the 2004 model year but will continue to sell a supercharged V8.

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