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. Honda quotes the 1967 RA300 as producing "over 420 PS" (414 bhp) at 11,500rpm. The vehicle weight excess over the 500 kg minimum had been approximately halved, with Honda quoting a weight of 590 kg.