15. Weight 15.1. Free.
16. Miscellaneous 16.1. Vehicles can have a starter motor mounted on either engine block or clutch cover. 16.2. Vehicles must comply with the silencing levels specified in Chapter. 7 App. 8 Art. 2.
16.3. All measurements must be in accordance with these Regulations when the car is unladen on a level horizontal surface.
16.4. Fuel must be Gasoline / Petrol as defined in Ch. 1 App. 1. 16.5. The lowest overall forward gear ratio is 23:1. 16.6. No Ballast may be carried.
Motorsport UK National Competition Rules 2026 Edition 1
Chapter 17 Appendix 6- Technical Regulations- HST Formula 635