The Chevron B31 was a sports prototype racing car built by Chevron Cars Ltd in 1975, and initially used in the European 2-Litre Championship. The car was an evolution of the Chevron B26, and was initially fitted with a 2-litre Hart 420R straight-four engine producing 290 hp (216.3 kW; 294.0 PS). However, various other engines were used; the car also ran with engines such as the 3-litre Cosworth DFV V8, the 2-litre Cosworth FVD/Cosworth BDG straight-four engines, and the 2-litre BMW M12 straight-four, amongst others.