When BMW announced its withdrawal from Formula One at the end of 1986, Arrows team principal Jackie Oliver negotiated an arrangement — supported by primary sponsor USF&G — to continue running the upright four-cylinder BMW engines under the Megatron name, a subsidiary of USF&G founded by long-time motorsport enthusiast John J. Schmidt. Engine servicing was entrusted to Swiss tuner Heini Mader, a former mechanic of Jo Siffert and the team's long-standing engine specialist.
Ross Brawn, later renowned for his work at Benetton, Ferrari, and Mercedes, designed the A10 as Arrows sought to remain competitive in the turbocharged formula's final years.
In 1987 all turbo engines ran under a mandatory FIA pop-off valve limiting boost to 4.0 bar, and each car was restricted to 195 litres of fuel per race. Arrows struggled throughout the year with an unreliable pop-off valve that frequently cut in far below the prescribed limit — Warwick reported at the Brazilian Grand Prix opener that boost was being restricted to as low as 2.6 bar in some instances, representing a loss of approximately 200 bhp relative to the already capped output of around 850 bhp in race trim.
Despite those handicaps, Cheever scored 8 points from a fourth place in Belgium, two sixth places in Detroit and Portugal, and another fourth in Mexico — a strong comeback after he had spent most of 1986 racing sportscars for Tom Walkinshaw Racing's Silk Cut Jaguar program. Warwick added 3 points with a fifth in the British Grand Prix and a sixth in Hungary. The A10 scored 11 points in total, lifting Arrows from tenth to seventh in the Constructors' Championship.
For 1988 the car received suspension and aerodynamic upgrades and was re-designated the A10B. The season context shifted dramatically in Arrows' favour: most competitors had moved to 3.5-litre naturally aspirated engines in preparation for the turbo ban coming in 1989, while Arrows retained the Megatron unit. The 1988 regulations also lowered the turbo boost ceiling to 2.5 bar and cut the fuel allowance to 150 litres per race, but the naturally aspirated field faced no fuel limit, giving the atmo runners a strategic advantage in longer stints.
The pop-off valve problem persisted for the first two-thirds of the season. The FIA unit was positioned too high above the engine, causing it to activate prematurely — a placement issue that Honda and Ferrari had long since resolved using factory engineering resources unavailable to Arrows. Mader finally diagnosed and corrected the problem just before the Italian Grand Prix at Monza, relocating the valve closer to the engine.
The fix produced an immediate and spectacular result. At Monza's speed-sensitive layout, Warwick and Cheever in the A10B recorded 310 km/h through the start-finish speed trap — faster than the McLaren-Hondas that won fifteen of the season's sixteen races. Eddie Cheever, running less downforce than his teammate, was clocked at 322 km/h through the Rettifilo, comfortably quicker than both the McLarens and Ferraris at that point. Cheever qualified fifth and Warwick sixth, separated by just 0.155 seconds, though both remained over 1.6 seconds behind pole-sitter Ayrton Senna. In the race, Cheever took the A10's only podium finish with third place, with Warwick fourth just 0.582 seconds behind him — the team's best-ever double result.
Warwick finished eighth in the Drivers' Championship with 17 points. Cheever added 6 points and finished twelfth. The A10B propelled Arrows to fifth in the Constructors' Championship — the team's highest-ever standing.
The Arrows A10 represents the high-water mark of an independent British team's efforts to compete in the turbocharged era without factory engine backing. Its story illustrates both the technical sophistication of the BMW four-cylinder unit and the resource gap between privateer outfits and works-backed programmes: a problem that took Heini Mader nearly two full seasons to solve had already been corrected by Honda and Ferrari engineers within a fraction of that time. Ross Brawn's design gave the car a competitive chassis that was repeatedly held back by a regulations compliance issue rather than fundamental performance deficiency. The Monza performance in 1988 stands as a testament to what the package was capable of when its full potential was finally unlocked.
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