1979: GM's use of half-baked diesel engines blows up on the automaker. Following the Arab oil embargo in 1973, carmakers looked for ways to improve fuel economy. GM's Oldsmobile division hit upon the idea of converting a conventional V8 into a diesel engine, which it introduced to consumers just as prices were taking off again in the wake of the Iranian Revolution. Good idea; disastrous results. The noisy diesel engines spewed smoke, broke often and generally alienated consumers. The diesel experiment finally ended in 1985, and GM never again put a diesel engine in a passenger car in the U.S. The diesel fiasco cost GM dearly and contributed mightily to the company's reputation for building unreliable cars. It also effectively neutralized the appetite of American consumers for diesel engines, which actually are more efficient than conventional gasoline engines.