McLaren entered 1988 having struggled with their dated TAG-Porsche engines, which could no longer match the manufacturer-backed teams. Honda, which had supplied championship-winning engines to Williams in 1986 and 1987, switched partners for 1988, bringing their 1.5-litre V6 turbo unit — developed and led by Osamu Goto — to McLaren. The transition was commercially significant: 1988 was the final season for turbocharged engines before the regulations mandated a return to naturally aspirated machinery.
The MP4/4 was a purpose-built all-new car, lower than its predecessor the MP4/3, which forced the drivers into a near-recumbent seating position. New FISA regulations required the driver's feet to be behind the front axle line in new cars, a stipulation that shaped the packaging. Six carbon-fibre chassis were produced with assistance from Hercules Aerospace. Ron Dennis paired Senna with Prost — at Prost's suggestion — on a three-year contract. The combination of the Honda engine, the McLaren chassis, and these two drivers represented an unprecedented concentration of capability.
The MP4/4 was instantly competitive, with Senna taking pole at the season opener in Brazil by half a second from Nigel Mansell's Williams-Judd. The car dominated qualifying to such a degree that at San Marino, third-place qualifier Nelson Piquet — using the same 1988-specification Honda V10 as the Lotus 100T — qualified 3.352 seconds slower than Senna. Both McLarens had lapped the entire field, including Piquet in third, by lap 55 of 60.
Honda's engine management team worked extensively on fuel consumption, as the regulations restricted turbocharged cars to 150 litres per race, while naturally aspirated cars ran without a fuel limit. The RA168E produced approximately 685 bhp and ran on a special Shell fuel blend incorporating toluene. The car's boost was reduced from 4.0 bar to 2.5 bar relative to the 1987 engine, but the combination of aerodynamic efficiency and fuel management allowed the McLarens to race comfortably on their allocation.
The MP4/4 retired only four times all season: Prost at Silverstone (handling in wet conditions), Prost at Monza (engine failure — the team's only race engine failure of the year), Senna at Monaco (crashing while 50 seconds in the lead on lap 66), and Senna at Monza (collision with Jean-Louis Schlesser while lapping him with two laps remaining, allowing Gerhard Berger to win for Ferrari). With both McLarens out at Monza, Berger's victory provided the season's sole interruption to the MP4/4's dominance, coming just weeks after the death of Enzo Ferrari.
Ayrton Senna took 13 pole positions, equalling his 1988 record with the MP4/5, and won eight races. Prost won seven races, finishing first or second in all 14 races he completed. The Constructors' Championship was settled at Belgium, the eleventh round, giving McLaren-Honda their eighth one-two finish of the year. The final margin was 134 points over second-placed Ferrari. Senna edged Prost in the Drivers' Championship by virtue of winning more races — the championship used a scoring system counting only the best 11 results, which allowed Prost's more consistent record to fall short despite his aggregate total being higher.
The top speed record for the MP4/4 was set during qualifying at Hockenheim, where both Senna and Prost reached 333 km/h on the long forest straight.
The MP4/4 was voted the greatest Formula One car of all time by a panel of Formula One engineers and designers and the greatest race car of the twentieth century by Autosport readers. Its win rate of 93.75% stood as the record for highest win rate in a single season until 2023, when the Red Bull RB19 — also powered by a Honda V6 — surpassed it. The MP4/4 also holds the record for the highest percentage of laps led in a season, at 97.3%.
All six chassis survive. Chassis 1 and 6 remain in McLaren Group ownership; the others are in private collections and institutional displays across the United States, Europe, and Japan. The car was used as a test mule — in a modified MP4/4B configuration — for the Honda 3.5-litre V10 that would power the 1989 McLaren MP4/5. The MP4/4 was the last turbocharged McLaren to win the Constructors' Championship until the Mercedes-powered McLaren MCL38 did so in 2024.