BMW has been in Formula One since the beginning of the World Drivers' Championship in . BMW entered several races in the 1950s and 1960s. Often, they ran using the Formula Two rules. In the 1980s, they built the BMW M12/13 inline-four turbocharged engine. This engine was built for the Brabham team. Nelson Piquet won the championship driving a Brabham-BMW. BMW also supplied the M12/13 engine to the ATS, Arrows, Benetton and Ligier teams. In , Brabham left F1 for the season, and BMW stopped its official backing of the engines. Arrows still used the engine with the Megatron name. When Formula One banned turbocharged engines in , the M12/13 could no longer be used.