The McLaren MP4/6 is a Formula One racing car. Honda RA121E V12 engine for use in the 1991 Formula One season. Ayrton Senna would win his third World Championship in the MP4/6. The MP4/6 was notable for being the last F1 car to win the championship with a manual gearbox and the only F1 car powered by a V12 engine to do so