Stock car formulas are largely split into two organisations broadly based in the north and south, BriSCA and Spedeworth.
BriSCA Formula 1 Stock Cars are the most sophisticated stock car formula. Each vehicle races with a race-tuned
V8 engine developing approximately 650 bhp. The cars are also fitted with quick-change axles, roof-mounted aerofoils, cambered wheels and brake setups for constant left turning. The
chassis of each vehicle is also offset. Large bumpers are mandatory and contact is encouraged to push opponents out of the way. The Smaller
BriSCA Formula 2 Stock Cars are also very popular. They are essentially a downsized version of the Formula 1 Stock Car, being powered by a 2-litre
Ford engine.
V8 Hotstox are a third BriSCA formula that race. They are a much cheaper class to race and use the
Rover V8 engine. This class is often used as a stepping stone to the Formula 1 class. Licensed and promoted by Spedeworth are the
Superstox. Superstox are similar to BriSCA Formula 2 Stock Cars with the main visual difference being a smaller wing on the roof. These cars are also powered by the 2-litre Ford Pinto engine. Spedeworth also run V8 Stock Cars, which are similar in design to the BriSCA Hotstox, but use small-block 5-litre
Chevrolet engines. Stoxkarts run 13 hp
Honda engines. This formula is one where more than one driver can use the same car in the same meeting. At the budget end of the racing spectrum is the rapidly growing Modstox formula. Visually similar to Formula 2 and Superstox, the formula is limited to the 850cc Reliant engine with other prescribed budget components, making it an ideal starter or 'last chance' formula for more senior drivers. ==Closed-wheel Stock car formulas==