3. Windscreen / Glass 3.1. Windscreens are mandatory for all closed Vehicles. They are free for open Vehicles.
3.2. Laminated windscreens lamp glass security and rear-view mirrors are not required unless specified in Official Documents or where there is a possibility of one car overtaking another.
3.3. Windscreen wipers must be operative on all Vehicles with windscreens.
4. Engines
4.1. Forced induction equivalence: 1.4 with the exception of Standard Road Cars( Art. 13) where forced induction equivalence is 1.7.
4.2. Rotary engine equivalence: 1.5. Forced induction rotary equivalence( 1.4 x 1.5) = 2.1 or( 1.7 x 1.5) = 2.55.
4.3. All engines must be provided with a means of starting which does not involve push starting or the use of external equipment or personnel except in the case of force majeure unless period defined or vehicles in possession of a Competition Car Log Book or Vehicle Passport prior to 31st December 2018.
4.4. Any connections to assist the starting of the car must be either in the Drivers’ cockpit or at the tail of the car requiring horizontal connection.
4.5. Undertrays: Must be provided with drainage holes to prevent accumulation of liquids.
4.6. Engine Oil Systems: Unless equipped with a closed loop system must have a catch tank of at least a one litre capacity to be incorporated in the oil breather system.
5. Wheels and tyres
6. Fuel
5.1. Except those of centre-lock type must have any nuts securing road wheels of steel and in thread contact over a minimum length of 1.5 bolt / stud diameters. Extended or composite wheel bolts / studs are prohibited.
6.1. For Standard Cars, Road Cars and Modified Cars: Permitted Fuel is mandatory. Only air may be mixed with the fuel as an oxidant.
6.2. Sports Libre and Racing Cars: Only Permitted Fuel or methanol may be used. When using methanol the addition of 10 % by volume of Propanone is allowable.
a.
Any Vehicle using methanol must include an approved additive which provides a distinguishable colour and smell when burning. The maximum permitted volume of additive within the fuel is 0.2 %. The Vehicle must carry a Day Glo orange disc 70mm in diameter positioned adjacent to all Competition Numbers.
6.3. Alternative fuels may be permitted subject to prior ASN approval.
6.4. All Vehicles must be equipped with an effective method of stopping the fuel supply operable by the Driver when normally seated and with seat belt / harness secured with the exception of Standard Cars as defined in Art. 13.1 below where it is recommend this is to be combined with or located adjacent to the internal ignition cut-off switch.
7. Electric Vehicles
7.1. Electrically powered vehicles are permitted subject to conformity with Ch. 7 App. 11 and any Official Documents( see Ch. 3 App. 10).
Motorsport UK National Competition Rules 2026 Edition 1
Chapter 14 Appendix 4- Technical Regulations 538