For the third consecutive season, McLaren used a 1986 version of the MP4 / 2 that debuted in 1984. The 1986 MP4 / 2C was a development of the 1985 "B", with refined aerodynamics, revised rear suspension and fuel tank. reduced to 195 liters as per regulation. This reduction in capacity caused some problems, but despite this Alain Prost won four grand prixes, securing the drivers' championship for the second time in a row. Lauda retired, Prost's teammate was Keke Rosberg.
1986 was the last season in F.1 for the Finnish Keke Rosberg, world champion in 1982. For 1986 Rosberg moved from Williams to McLaren, alongside Alain Prost. With a theoretically very competitive car, he did not achieve sensational results: his best placing was a second place in Monaco. He also scored a pole position in Germany. Rosberg ranked 6th in the drivers' championship with 22 points.