The Vega would be an all-new car unrelated to any other in G.M.’s portfolio, using an all-new engine, and it would be built at the company’s newest, most automated plant, in Lordstown, Ohio. “The Vega came just as the bean counters were rising at G.M.,” said John Heitmann, a professor of history at the University of Dayton, about G.M.’s changing corporate culture.

“From the first day I stepped into the Chevrolet division, in 1969, it was obvious that the Vega was in real trouble,” DeLorean said. “General Motors was pinning its image and prestige on this car, and there was practically no interest in it in the division.”

Chevrolet had proposed its own small-car design and was turned down; as production approached, the Chevy staff’s disdain for the corporate model — heavy for its size and more costly to produce — grew.

Worst of all, its 4-cylinder engine was an unfortunate mix of innovation and archaic design. The cylinder head was made of cast iron, a conventional practice for the time, but a special aluminum alloy was chosen for the engine block.

“What resulted,” DeLorean said, “was a relatively large, noisy, top-heavy combination of aluminum and iron, which cost far too much to build, looked like it had been taken off a 1920 farm tractor and weighed more than the cast-iron engine Chevy had proposed, or the foreign-built 4-cylinder engine the Ford Pinto was to use.”

The engine wasn’t particularly powerful; breathing through a one-barrel carburetor, it produced a piddling 90 horsepower; with a two-barrel carburetor, that rose to 110. When the ratings were revised in 1972 to net power output — from the gross horsepower rating used previously — those figures dropped to 80 and 90 horsepower.