Front engined: 14 psi Mid / rear engined: 20 psi
1.6. CLASS D SERIES PRODUCTION CARS NOT ELIGIBLE FOR ANY OTHER CLASS AND KIT CARS
a. RWD SERIES PRODUCTION CARS
2. General
Permitted modifications in accordance with Arts. 2.1 – 10.5. Minimum tyre pressures on driven wheels: FE Sports Cars up to 1800cc: 16 psi FE Saloon Cars up to 1800cc: 14 psi RE Cars up to 1000cc: 22 psi FE Sports Cars over 1800cc: 22 psi FE Saloon Cars over 1800cc: 20 psi RE Cars over 1000cc: 26 psi b. MODIFIED SERIES PRODUCTION CARS AND KIT CARS **
Cars( not eligible for Classes A, B or C) complying with App. 3 Art. 1 Classes 1-6 and 7( b) and front engined Kit Cars modified beyond Car Trials Formula regulations and up to the limits specified in App. 3 Art. 1 Class 7( c), and with the ACTC approved specification readily available for inspection. App. 3 Art. 1.2 does not apply as MoT is not required when off road. The Car Trials Wheel and Tyres regulations Art. 8.2 – 8.3 must be complied with. Minimum tyre pressures on driven wheels: FWD Cars: 16 psi FE Kits Cars: 24 psi FE RWD Cars: 22 psi RE Cars: 26 psi
** Compliance shall not extend to App. 3 Art. 7.1 or Art. 8.2 below i. e. only wheels of the sizes detailed in their ACTC specification may be used. In all other cases of rule compliance Classic Reliability Trial Vehicles’ regulations will prevail.
2.1. * Any car fitted with a torque biasing differential or any other form of traction control as catalogued for that car may have tyre pressures set at 4psi above the specified Class pressure.
2.2. Cars with an overall length of 166 inches and over in Classes A and B above may reduce tyre pressures by not more than 4 psi subject to an absolute minimum pressure of 10 psi.
2.3. Optional or alternative equipment as listed by the manufacturer may be fitted with the exception of gear and differential ratios.
2.4. Special tuning and competition catalogues etc. are not acceptable as manufacturer’ s handbooks.
3. Safety
3.1. Vehicles must comply with Construction and Use Regulations and be fitted with safety belts if appropriate. The following are recommended:
4. Chassis / Body
a. Safety roll-over bar to safety criteria Ch. 7 App. 3 Art. 22 and Art. 23. b. The wearing of seat belts is optional when fitted to the vehicle..
c. Handheld fire extinguishers to safety criteria Ch. 7 App. 6 Art. 3( note a 1.75ltr minimum for AFFF or 2 x 1ltr AFFF or 2 x 1Kg Powder is permitted).
4.1. Vehicles should not have any chassis or body alterations except:
Motorsport UK National Competition Rules 2026 Edition 1
Chapter 17 Appendix 4- Technical Regulations- Car Trials Formula 623