Mercedes-Benz of North America has introduced the first turbo-charged production diesel automobile, a $24,000, five passenger sedan. The Germany company expects to sell them some 4,000 before Dec. 31.

The 3,900-pound 300SD Mercedes boasts fuel economy of 26 miles per gallon comosite, 24 mpg, city and 29 mpg highway on EPA test according to Mercedes executives. The 112.8-inch-wheel-base car carries nearly every imaginable option on it as standard equipment.

Karfried Nordmann, president of Mercedes-Benz North America said the car "was specifically designed" for the U.S. market. While the rest of the auto world is focusing on down sizing to smaller and lighter models, "the 300SD shows it is possible to build a full-sized car with good performance and economy," he said.

In many ways the 5-cylinder diesel care represents the technical changes coming soon from all auto makers worldwide as they try to vastly increase fuel economy without excessively degrading driving performance. Even with the turbo-charger, the 300SD takes a leisurely 15.9 seconds to reach 60 miles per hour from a standing start.

The turbo-charger is an old device that compresses the air going into the engine and thus give extra horse-power. It is commonly found on the large trucks and tractors, but is rare on automobiles today. Both the Buick Division of General Motors Corp. and the Swedish auto maker SAAB are not selling turbo-charged gasoline engines.

The Mercedes diesel is rated at 77 horsepower without the turbocharger with it, it yields 110 hp.

Mercedes-Benz also announced a sales contest that will give a 300SD to the owner of the highest-mileage Mercedes diesel and the owner of the oldest Merceds diesel in the United States.

Mercedes sells 45,000 to 50,000 handsomely priced cars in the U.S. each year. For nearly five years, just under half have been powered with diesel engines.

A short test drive of the 300SD found the car luxurious, with the typical "clatter" noise of diesels, and a decidedly sedenatry feel on the accelerator. When pushed for serious acceleration on the road, the car moved as though it had a strong V8 under the hood.

Manfred Fortnagel, chief of passenger car diesels for the parent company, Daimler-Benz of Stuttgart, said the sluggish feel is typical of any diesel vehicle and with minimal driving experience would not be noticed.

Nordmann said he expects to selling 9,500 300SDs in North America during 1979.