This 1979 Cadillac Fleetwood Brougham sedan was available with an optional diesel V-8.

The Cadillac Diesel V-8

The Cadillac diesel V-8 debacle was one of several mistakes that contributed to the weakening of Cadillac's stature and sales that began in the late-1970s.

The Cadillac diesel V-8 was America's first production passenger-car diesel engine. It was an option on every 1979 Cadillac, which otherwise used a gasoline V-8 of, depending on model, 350 cubic inches and 170 horsepower or 425 cubic inches and 180 or 195 horsepower.

Initially offered for the 1978 Cadillac Seville, the Cadillac diesel V-8 was basically a "dieselized" version of Oldsmobile's familiar 350-cubic-inch gasoline V-8. It was rated at just 125 horsepower, but had a credible 224 pound-feet of torque. Olds built it for all GM brands, itself included. Smooth and quiet for a diesel, it gave Cadillac a direct reply to diesel Mercedes-Benz models.

More important, it helped Cadillac contribute to GM's compliance with the corporate average fuel economy (CAFE) mandates that took effect with model-year 1978. That's because diesels use up to 20 percent less fuel than comparable gasoline engines.

As time passed, however, it became clear that some people bought a diesel Mercedes not for fuel economy or a diesel's renowned longevity, but for the prestige of the three-pointed star.

That was understandable. Less comprehensible was the damage the GM diesel did to Cadillac's image.

The Olds engine suffered early and persistent reliability problems that GM never could seem to fix. With all this, Cadillac diesel sales were never significant, even once a second energy crisis erupted in spring 1979 to upend the car market and the national economy.

For more information on Cadillac, see:
  • Cadillac: Learn the history of America's premier luxury car, from 1930s classics to today's newest Cadillac models.
  • Consumer Guide New Car Reviews and Prices: Road test results, photos, specifications, and prices for 2007 Cadillacs and hundreds of other new cars, trucks, minivans, and SUVs.
  • 1960-1969 Cadillac: See how Cadillac maintained its hold on the premium market by adroitly addressing changing consumer demands.
  • 1980-1989 Cadillac: America's top luxury brand was in crises in the 1980s. Learn about how it weathered the storm.