Honda had been supplying Formula One engines since their return to the sport in 1983. By 1987, their turbocharged V6 engines were a dominant force, powering Williams to the Constructors' Championship and Nelson Piquet to the Drivers' title. For 1988, the regulations introduced significant restrictions: the maximum fuel allowance was cut to 150 litres per race and the maximum turbo boost pressure was reduced from 4.0 BAR to 2.5 BAR. These changes required a fundamentally new engine rather than a further evolution of the existing unit.
Honda responded by building an all-new V6 turbo specifically engineered to perform within the tighter constraints. Unlike the previous arrangement in which Williams used the latest specification and Lotus received the older RA166E, the 1988 engine — designated the RA168E — was supplied in identical specification to both McLaren and Lotus, who were Honda's two customer teams that season.
The RA168E was mated to the Steve Nichols-designed McLaren MP4/4, with Alain Prost and Ayrton Senna as the two drivers. The combination proved devastatingly effective. McLaren-Honda claimed 15 pole positions from the season's 16 races, 13 of them taken by Senna. The partnership won 15 of the 16 Grands Prix, with Senna taking eight victories — a new single-season record at the time — and Prost adding seven more, which equalled the previous record he jointly held with Jim Clark.
McLaren-Honda accumulated 199 points in the Constructors' Championship, a total that stood as a record for many years. The margin of victory over second-placed Ferrari was 134 points. Gerhard Berger in the Ferrari was the only non-Honda-powered driver to take a pole position that season, at the British Grand Prix, and the only non-Honda driver to win a race, at the Italian Grand Prix. Senna secured the Drivers' Championship despite Prost scoring more raw points over the year; under the rules of the era, only the best eleven results counted, which delivered the title to the Brazilian.
The final race of the season, the 1988 Australian Grand Prix in Adelaide, brought down the curtain on the original turbo era in Formula One. Honda-powered drivers filled the podium, with Prost winning ahead of Senna and Lotus driver Nelson Piquet in third.
The RA168E was engineered to extract maximum performance within the severely constrained fuel and boost regulations. Honda's intensive internal development programme meant the company was reportedly producing and testing multiple different engine variants within a single season. The engine's reliability was also a key factor in the 1988 campaign, as the fuel limit left little margin for inefficiency, and any mechanical failure or wasteful running risked leaving a car short of fuel before the finish.
The 1988 season powered by the RA168E stands as the benchmark for Formula One dominance. McLaren's record of twelve consecutive race victories, set in the same year, held until 2023 when Red Bull Racing broke it — powered by engines built by Honda, in the form of the Honda RBPT power units used by Red Bull. The coincidence was noted widely: Honda broke their own record in the process. The RA168E therefore bookended one of the sport's most extraordinary chapters, its achievement serving as both the high point of Honda's first turbo era and a measuring stick against which later generations of Honda-powered machinery would be judged.