GM experimented with aluminum engines starting in the early 1950s. Aluminum Company of America (ALCOA) was pushing all automakers to use more aluminum. An early-development supercharged version of the V8 was used in the 1951 Le Sabre concept car, and the 1953 Buick Roadmaster concept car, and work on a production unit commenced in 1956. Originally intended for displacement, Buick was designated by GM as the engine design leader and decided to begin with a larger, size, which was deemed ideal for the new senior compact cars introduced for the 1961 model year. This group of cars was commonly referred to as the B-O-P group — for Buick-Olds-Pontiac — or the Y-bodies.