The Family 1 is a straight-four piston engine that was developed by Opel, a former subsidiary of General Motors and now a subsidiary of PSA Group, to replace the Opel cam-in-head engines for use on mid-range cars from Opel/Vauxhall. Originally produced at the Aspern engine plant, production was moved to the Szentgotthárd engine plant in Hungary with the introduction of the DOHC version. GM do Brasil at São José dos Campos, GMDAT at Bupyeong and GM North America at Toluca also build these engines.