Autograss

The cars are standard 1000-cc Minis. As with all Autograss cars, they have the trim, dashboard, and seats removed. The engine is standard with limited modification allowed (rebored +60 etc.). The only engine capacity allowed is 998cc bar Minis which may be modified to 1058cc to compensate. Juniors aged 10–16 are allowed to drive class 1 cars in separate races. This class was previously restricted to Minis, but the Peugeot 106, Nissan Micra, Toyota Yaris and Citroën AX have been added to the list of eligible cars from 2006. Other experimental cars are being added to the list as the classic Mini is becoming more expensive and harder to source. In addition to this, it is no longer as competitive against more modern cars that are being allowed in. The intention of class 1 racing is to maintain an entry level class that can be constructed at a low cost, with an initial outlay of under £500 and minimal running costs at club level. Despite this, race winning cars and versions that are competitive at national level tend to cost about ten times that figure and more.

Class 2 is open to front- or rear-wheel drive vehicles with a 1300cc engine. Engine placement can be either front or back. Vauxhall Novas, Nissan Micras, and Ford Fiestas are the vehicles in this class that are most frequently seen. Since front-wheel drive vehicles were made available in this class, class 2 drivers have grown to love the Vauxhall Nova. The use of 1275cc Minis and Metros is prohibited since there is a minimum length limit and only 2 valve/cylinder cars are permitted. A restrictor is installed in the inlet manifold to balance performance throughout the diverse range of vehicles used.

This is the first of the unlimited capacity classes. The cars must have engines at the front and be rear wheel drive. This class allows front wheel drive cars to be converted to rear wheel drive and 16v engines with a maximum of 2065cc, engines with two valves per cylinder are unlimited in cc. This leads to powerful cars which are lightweight and fast. Examples of cars in this class are Toyota Starlets, MKII Ford Escorts and Ford Anglias.

Class 4 a modified class, with engine capacities allowed up to 1130cc. Any engine modification is allowed, except turbo and super charging. Engines are extensively modified to bring them to a competitive level, as a specific of the rules is that the original engine and position are retained. Examples of cars in this class are Minis, Hillman Imps, Citroen Saxos, Nissan Micras and Peugeot 106s.

This is a very popular starting point for people wanting to drive modified saloons. Engine capacities from 1131 to 1420cc are allowed, the engine does not have to be the original or in the original position. A lot of cars run rear engines to help improve grip.

Class 6 is for cars with unlimited engine capacity and modifications in a front engine/front wheel drive combination. Costs can be in the region of £2000 to £10000.

Class 7 restricted to rear wheel drive cars. The engines are unlimited, but must be above 1421cc, or 1000cc if a bike engine. Many class 7 cars use motorcycle engines, in which case 2 engines may be used to power the vehicle. Engines for these cars are often very costly, including Cosworth turbo motors, large block American V8s, and V6s of different types, all highly tuned.

This is the most competitive of the Special Classes and has lowest engine capacity limit, a maximum of 1420cc for car engine specials and 1350cc for bike engine specials. Engines may be tuned, but not be turbo or super charged. The majority of cars are rear-engine; this is not part of the regulations but is the most effective way to get the most weight over the wheels.

This is the class most likely to win an open-class race. This class combines the high power output of the modern 2.0 litre engine with the lightness to allow better handling than the heavier class 10 vehicles. The capacity limits are between 1421cc and 2070cc and any modifications are allowed, with the usual exception of turbo and supercharging. All cars are mid-engine with most utilizing a transverse gearbox layout and rear wheel drive.

Class 10 is one of the most powerful classes within Autograss racing. Another of the purpose-built classes, this one has a minimum capacity of 2071cc but no upper capacity limit or limit on the modifications made to the engine (except that motorcycle engines may not have forced induction). Twin bike engines are popular with the capacity limits being between 1550cc and 4000cc, as is V8 power. This is the class where racers on a budget can get real value for their money with a relatively small amount of money being spent for the power although car build budgets can extend to over £50,000.

This consists of single seaters in which all cars have an almost standard 1.2 Vauxhall Corsa engine. As with the junior class one saloons, this class is for 10- to 16-year-olds.

There are some other classes found in specific clubs, for example F600's were designed to be a cheaper less powerful special that was designed to give drivers easier access into the special classes. The specifications are single 600cc engines situated in the rear with the power going towards the rear wheels. The F600's are used mainly by smaller clubs but can be found everywhere.

There is also a Stock Hatch class which use near standard saloons up to 1600cc capacity.

Neither class is recognized as a stand-alone class by the governing body (NASA), when they race they have to race in Class 8 or 9 for F600s and Class 6 for Stock Hatch.