Automotive innovation often comes from the top down. The first appearance of air bags, CD players and anti-lock brakes were first made available in expensive, top-of-the-line cars. Once the technology was proven and costs were reduced, the innovations eventually spread to most other cars.

The latest innovation now appearing in cars dramatically boosts fuel efficiency without sacrificing performance. It also reduced carbon dioxide and carbon monoxide emissions by 25 percent. Unlike the gasoline-electric hybrid engines from Toyota and Honda getting so much attention, this "innovation" was invented in Europe over 100 years ago - the diesel engine.

Calling diesel engines a new automotive innovation is not quite accurate. Diesel engines in passenger cars might be new to the U.S., but in Europe they are found under the hood of nearly half of all new cars sold in recent years. With fuel on the other side of the Atlantic Ocean priced at nearly twice the U.S. per-gallon figure, Europeans have wholeheartedly embraced modern, clean-diesel technology. That same technology is now coming to the U.S. Diesel-powered cars might start slowly, but diesel engines should find acceptance among millions of American drivers for the same reason's Europeans have found so compelling.

German automaker Volkswagen has offered diesel engines in some its cars sold in the U.S. The Passat model is scheduled to feature a diesel engine in 2004.

But the bigger headlines in car magazines and the popular press are being written about a new diesel-powered car from Mercedes Benz, the E320 - the first Mercedes diesel car sold in the U.S. since 1999.

Mercedes, which produced the first diesel car in 1936, might represent the crest of the first wave of new diesel-powered cars to be sold in the U.S. In addition to Volkswagen's models, Chrysler will be selling a diesel-powered version of the Jeep Liberty in the fall.

Diesel engines are generally 30 percent to 40 percent more efficient than a comparable gasoline engine. Smaller diesel cars get fuel economy rivaling the much ballyhooed new Japanese hybrids.

It is intriguing to imagine the new fuel efficiency standards that will be set when car makers incorporate the latest hybrid technologies with modern diesel power plants.

Increase mileage is a powerful message, especially at a time of $2 per gallon gas. But broad public acceptance of diesel cars in the U.S. will require that people forget the image of the diesel cars of the 1980s - noisy, smelly and soot belching. Today's modern diesels are quiet, clean, powerful - and efficient.

American drivers only have to look at and drive a modern diesel to become convinced. Rapid acceptance of diesel-powered cars and SUVs could have a significant impact on reducing the amount of imported oil consumed by American motorists.

If past technology evolutionary paths and Europe's recent experience mean anything, the diesel engines found only in the 2004 Mercedes, Volkswagens and Jeeps could well become a widely available option from most other auto makers in the coming years.

- J.L.W.III