The British Racing Motors project was conceived in the aftermath of World War II as a national effort to build a dominant British Grand Prix car. The V16 engine was designed by a team led by Peter Berthon, with Harry Mundy, Eric Richter, and Frank May. It was conceived as two 750cc V8 engines joined back-to-back, with cam drives and gears at the centre of the crankshaft. Components were manufactured across approximately 350 British companies, many of whom donated parts or produced them as a contribution to the project rather than a commercial order. English Steel provided the crankshaft, Standard Motors machined the main engine components, and David Brown supplied the gears.
Rolls-Royce designed and built the two-stage centrifugal supercharger, which ran at up to 82.6 pounds per square inch boost. The flame traps Rolls-Royce developed for the inlet manifold — required to prevent backfires in the highly compressed fuel-air mixture — were a first on any automobile engine, borrowing from wartime aero-engine practice. The chassis was manufactured by Rubery Owen, with rear suspension derived from the prewar Mercedes-Benz W165 and trailing arm front suspension from Auto Union. Girling supplied special three-leading-shoe drum brakes, later upgraded to disc brakes that made the BRM the first Grand Prix car fitted with them.
The completed car ran for the first time at RAF Folkingham in December 1949, driven by Raymond Mays.
Plans to debut the car at the 1950 British Grand Prix at Silverstone, the opening race of the new Formula One World Championship, were abandoned after persistent engine problems including cracking cylinders, buckling connecting rods, and piston failures. BRM instead displayed the car at Silverstone, where Princess Elizabeth and Prince Philip witnessed it complete several demonstration laps.
The race debut came at the August 1950 Daily Express meeting at Silverstone. The one prepared car had missed practice sessions but was permitted to start from the back of the grid after completing three proving laps. When the flag dropped, the BRM lurched forward and stopped immediately, its inboard universal joints having failed, as the Daily Express was simultaneously distributing a glossy brochure celebrating the new car's promise.
The car's fortunes improved at Goodwood in September 1950, where Reg Parnell won two races including the Goodwood Trophy despite wet conditions limiting the car's full power. At the 1951 British Grand Prix, both Parnell and Peter Walker ran the car to fifth and seventh place respectively, despite suffering extreme cockpit heat from exhaust pipes routed inside the bodywork — both drivers needed burn dressings on their legs during pit stops to tolerate the temperature.
In 1952, the team intended to contest an April race at Valentino Park, Turin, but Raymond Mays withdrew the cars while pursuing Juan Manuel Fangio as a potential driver. Without BRM, Ferrari finished in the first six places unopposed, and the race organisers subsequently abandoned the Formula One supercharged formula and ran the remaining season's events under Formula Two regulations. The BRM, by not appearing at Turin, directly contributed to the abolition of the formula for which it had been designed.
At the 1952 Ulster Trophy, Stirling Moss drove one of the BRM Type 15s but both cars failed to finish. Moss subsequently wrote to Mays stating he would not drive the car again in its current unreliable state. Later in 1952 at Goodwood, three BRMs finished first, second, and third. Fangio tested the car at Folkingham and declared it the most formidable car he had ever driven, later saying it gave him a greater sense of absolute mastery than any other. However a crash at Monza while driving for Maserati, in which Fangio broke his neck, ended his association with BRM for the remainder of that period.
The Type 15 Mark II, also designated the Type 30, was a shorter-wheelbase lightweight derivative developed on the suggestion of Tony Rudd. Two were built, one from salvaged components after Ken Wharton's accident at Albi in 1953. At the Albi sprint race that year, Fangio drove a Type 30 to heat victory against Alberto Ascari's works Ferrari, with the engine recorded at 72 pounds per square inch boost and 585 horsepower at 11,800 rpm, reaching over 190 mph.
The V16 engine displaced 1,487.76 cc across a 135-degree V configuration. Bore measured 1.95 inches and stroke 1.90 inches. Two valves per cylinder were operated by twin overhead camshafts per bank, driven by a gear train from the crankshaft centre. Hairpin valve springs were used. The crankshaft was a counterbalanced two-piece unit initially running in eight plain bearings and two main roller bearings, later revised to ten plain bearings. Raymond Mays recorded a peak power output of 600 horsepower at 12,000 rpm with the 4.0:1 supercharger; Tony Rudd's data showed a peak of 612 horsepower.
Despite its Formula One record of only two starts and one points finish across four championship entries, the BRM P15 ultimately became quite reliable once its teething problems were resolved — too late, as the formula it was built for had already been abandoned. Juan Manuel Fangio's assessment never wavered: he called it the most fantastic car he ever drove, an incredible challenge in every way. Mike Hawthorn, by contrast, found its violent power delivery below 8,000 rpm unmanageable. In 1968, Graham Hill demonstrated the car in South Africa, revving the engine to 13,000 rpm where Tony Rudd estimated it was producing around 780 horsepower.
A total of four Type 15s were produced. One survives at the National Motor Museum in Beaulieu; another is displayed at the Donington Grand Prix Exhibition in original light green livery alongside a P30 and a cutaway V16 engine. A fourth surviving car, a P30, was owned by Bernie Ecclestone, having previously belonged to Pink Floyd drummer Nick Mason.