The McLaren MP4/2 was designed by John Barnard of McLaren for the 1984 season. An iteration of it, the MP4/2B, was used in the 1985 season, and a slightly updated version, the MP4/2C, raced in the 1986 season for McLaren. It was closely based on the MP4/1E model that was used as a test car, used in the final races of 1983.

Like most of its major competitors (other than the Williams FW09), the car used an all carbon fibre chassis pioneered by the car's designer John Barnard with its predecessor, the MP4/1. The car was powered by a 1.5 Litre, 90° V6 TAG-Porsche turbo engine that produced 650bhp in race set-up and up to 800bhp in qualifying set-up i.e. with maximum turbo pressure. It was first used in the 1983 Dutch Grand Prix, at the insistence of veteran Niki Lauda, who felt that the new engine required race testing before a championship challenge could be mounted.