The Diesels Are Coming Back; M-B delivers a diesel-the first of what promises to be many more.(News)

Byline: ROGER HART

Rewind the clock about 20 years and besides looking at some bad clothes and the pinnacle of rock 'n' roll hair bands, you'd see diesel-powered cars accounting for 80 percent of all Mercedes-Benzes sold in the United States. The company has a long history of making diesels (it was the first to put a diesel in a passenger car, in 1936) and the spike in gasoline prices in the 1970s and early '80s made diesels a practical choice. For a couple of decades in this country, diesel and Mer-cedes went hand in hand.

All that changed in 1999 when, for a variety of reasons (including stricter emissions regulations, stability of gasoline prices and a redesigned E-Class body that didn't allow for the tall diesel engine to fit underhood), Mercedes-Benz stopped selling diesels in the United States.

Now it makes its return with the E320 CDI (Common-rail Direct Injection) sedan, unveiled at Detroit in January. Aesthetically identical to its gasoline-powered siblings (AW, March 11, 2002), the E320 CDI is powered by a 3.2-liter inline six-cylinder with double-overhead cams and four valves per cylinder, mated to a five-speed automatic transmission. A variable nozzle turbine and an inter-cooler help the turbodiesel produce 201 hp at 4200 rpm and 369 lb-ft at 1800 to 2600 rpm. The diesel engine will propel the 3835-pound car from 0 to 60 mph in an estimated 6.8 seconds. In comparison, the gas-fed E320 makes 221 hp at 5600 rpm and 232 lb-ft at 3000 to 4800 rpm. The gas car is 0.3 second slower from 0 to 60 mph.

Our first drive of the E320 CDI was in the hill country north of San Antonio. Mercedes has worked hard to eliminate one of the knocks against diesel: noise. Thanks to extra sound deadening throughout the car, while seated in the cabin you can barely hear the engine running. At idle, as measured outside, the diesel is a bit louder (two decibels) than the gas mod-el, but at full throttle it is actually quieter, probably thanks

to the turbo, but also because it just doesn't rev as high as the gas engine. The loudest noise we heard on our test drive was turbocharger whistle.

Diesel's advantage, in addition to great fuel mileage, is a prodigious amount of torque available over a wide rev range, and the E320 CDI does not disappoint. If prospective customers drove the diesel and ...