Broadley's chassis was much lighter and sweeter-handling than the in-house RA273. The car initially performed impressively, winning in its first-ever World Championship race, the Italian Grand Prix at Monza. Driver John Surtees took the lead from Jim Clark's Lotus and Jack Brabham's Brabham on the final lap, after Clark ran out of fuel and Brabham ran wide. However, the RA300 flattered to deceive, and this would turn out to be the only lap that the car would lead. It remains the only F1 car ever to take its single victory in its very first Grand Prix, and on the only lap it would ever lead.
On display at the IAA exhibition in Frankfurt, 2007.
Honda continued with the RA300 for the remainder of the 1967 season, Surtees finishing fourth at the final race in Mexico. The car was then raced one last time at the opening race of the 1968 season in South Africa, Surtees finishing eighth, before being superseded by the RA301, a design closely based on the RA300.
The 48-valve V12 engine first appeared in the RA273 at the 1966 Italian Grand Prix, driven by Richie Ginther. In spite of weighing 740 kg (dry), it was capable of spinning the rear tyres at 100 mph in third gear. With cylinder dimensions of 78.0 x 52.2 mm and a displacement of 2,993.17 cc, a target of 400-440 bhp at 12,000 rpm was quoted. The engine used by Surtees at Monza in 1967 was quoted by Motoring News as developing only 396 bhp, but with improved torque and response. The vehicle weight excess over the 500 kg minimum had been approximately halved.
Formula One World Championship results
(key) (results in bold indicate pole position; results in italics indicate fastest lap)