ENGINE TROUBLE

Carmakers have been trying to perfect the auto engine ever since Karl Benz invented it in 1879. By the 1970s, rotary engines, which create power using a triangular rotor instead of pistons, were considered the next big thing, partly because because fewer moving parts were supposed to make them more reliable. Mazda and General Motors made particularly big—and badly timed— bets on the technology, which crashed amid the oil crisis:

“The rotary engine, to be sure, isn’t dead, but its once-glowing prospects have been dealt a serious blow by the fuel shortage. The buyers want a car that gets good gas mileage, and there are large doubts about the rotary engine on that score. They were underlined last year when the Environmental Protection Agency reported that the Mazda got no better than 10.6 miles per gallon of gasoline.” —Forbes, March 15, 1974

The rotary engine never took off. Few automakers aside from Mazda ever used it, and Mazda’s last production car with one rolled off the line in 2012.