The McLaren MP4/5 and its derived sister model the McLaren MP4/5B were Formula One racing cars designed by the McLaren Formula One team based in Woking, UK. The MP4/5 was loosely based on its 1988 predecessor, the all-conquering MP4/4.
McLaren used the new car for half of the 1989 season using the Weismann Longitudinal Transmission from the MP4/4, and the MP4/5B with the Weismann Transverse Transmission for the last half of the 1989 season and for 1990, earning back to back drivers' and constructors' world titles with the type.
The car was designed by American engineer Steve Nichols who previously had designed both of its turbocharged predecessors, the MP4/3, which was an all-new design for McLaren by Nichols, as well as its highly successful MP4/4 the following year/season.
McLaren responded with a modified version of the MP4/5. The wings were redesigned and the rear bodywork reprofiled around larger radiators. The engine was tweaked and Senna did much development work to ensure he would have better reliability in the new season. He and Gerhard Berger took the fight to Prost and Ferrari in 1990, winning another six races and winning the Constructors' Championship.
The McLaren proved to have an outright speed advantage in qualifying and was notable for the number of times both cars were on the front row. The car appeared to struggle slightly against the Ferrari 641s in the race, particularly on heavy fuel loads with the Ferraris' race pace almost negating the McLarens' qualifying supremacy.