In addition in the late-1960s, GM directed their GM and Pontiac divisions to develop concept mini-cars called commuter cars for urban drivers. GM developed a gasoline-electric drive hybrid, the XP-833, and the Pontiac X-4, a rear-wheel drive mid-engine car that was powered by a radical X-shaped aircraft type air-cooled two-stroke radial engine where the standard crankshaft was replaced by a unit called a Scotch yoke. While the GM car was fully tested, the Pontiac concept was not. Neither was placed in production.
In addition in the late-1960s GM directed their GM and Pontiac divisions to develop concept mini-cars called commuter cars for urban drivers GM developed a gasoline-electric drive hybrid the XP-833 and the Pontiac X-4 a rear-wheel drive mid-engine car that was powered by a radical X-shaped aircraft type air-cooled two-stroke radial engine where the standard crankshaft was replaced by a unit called a Scotch yoke While the GM car was fully tested the Pontiac concept was not Neither was placed in production