The MP4/6 marked McLaren's first use of a Honda V12 engine, the RA121E, which Honda quoted at 735 PS at 13,500 rpm. During pre-season testing, both Berger and Senna expressed disappointment with the initial V12 output, finding it felt no more powerful than the V10 used in the preceding MP4/5B despite the extra cylinders. Honda and McLaren responded by intensifying development, and by the second half of the season the engine had been improved to 780 hp at 14,800 rpm.
The car raced throughout 1991 with a traditional manual "H" pattern gearbox. A semi-automatic transmission was tested during the season and briefly shown at the Hungarian Grand Prix, but after Senna spun off during a short practice run, the experimental car was converted back to manual and never considered ready for race use. Ferrari and Williams were the only teams to race with semi-automatic gearboxes in 1991, leaving the MP4/6 as the last championship-winning car to rely on a manual transmission.
Senna opened the season with four consecutive victories in the United States, Brazil, San Marino, and Monaco, establishing an immediate dominance. However, as the year progressed, the Williams FW14 and Nigel Mansell found their stride, with the aerodynamically advanced Renault-powered Williams dominating the mid-season. McLaren's early advantage was aided in part by the FW14's early reliability issues.
Senna's consistent podium finishes kept the championship alive. He pressed Honda for engine upgrades and pushed Oatley's team to revise the car's sidepods and wings. The efforts produced results: Senna won in Hungary and Belgium before clinching his third and final Drivers' Championship with second place at the Japanese Grand Prix, behind Berger, who took the win. Senna then claimed victory at the season finale in Australia, rounding off the Constructors' Championship for McLaren.
In total, the MP4/6 took eight Grand Prix victories, ten pole positions, and scored 148 championship points across the season.
McLaren carried the MP4/6 into the start of the 1992 season in upgraded "B" specification, racing it at the first two events before the new MP4/7A was introduced. Senna finished third in South Africa with the MP4/6B. Three MP4/6B chassis were also brought to the 1992 Brazilian Grand Prix as spare cars.
The MP4/6 is regarded as the car that closed out McLaren and Honda's era of dominance in Formula One, a period stretching back to the mid-1980s. While it ultimately proved less aerodynamically advanced than the Williams FW14, Senna's driving ability and Honda's engine development program allowed McLaren to prevail. The car's technical legacy rests on being the sole Formula One world championship winner to use a V12 engine, and the final champion to require a driver to manually change gears.
The McLaren MP4/6 has appeared as a classic car in several Codemasters F1 titles, including F1 2017, F1 2018, F1 2019, and F1 2020. It is also featured in Automobilista 2 alongside the McLaren MP4/7A and MP4/8 in a dedicated McLaren classics pack.
Gallery · 2 related images
