Group T4
The Fédération Internationale de l'Automobile launched Group T4 in 1990 to facilitate rally trucks in rally raid competitions. The regulations are included in appendix J of the International Sporting Code. Competition. Group T4 trucks compete in the FIA Cross Country Rally World Cup since its inception in 1993. However T4 trucks can compete, the trucks are not eligible to compete for the general classification or have a group classification. The trucks can only compete for local rally raid victories or class victories. The Dakar Rally, Baja Aragón, Abu Dhabi Desert Challenge among other rally raids form the FIA  Cross Country Rally World Cup. Group T4 vehicles are allowed to compete in other rally raid competitions as well, such as the Silk Way Rally. Regulations. Trucks eligible for Group T4 homologation must comply with a fixed set of rules according to Appendix J, article 287. The truck must be a production based chassis and have conventional bodywork. The laden weight has a minimum of 3.500kg. Despite certain modifications, the engine is a stock production engine. While the Unimog U500 engine is 'only' 6374cc, the engine of most trucks exceed more than 10000cc. Because of safety regulations, the cabs  have a very strong roll cage. A diagonal bar in the rear of the roll cage is mandatory. More diagonal struts are advised. Rally raids such as the Dakar Rally and the Silk Way Rally have added rules to the standard Group T4 rules. The Silk Way Rally bases its rules on the Dakar Rally. Both rallies know sub groups to Group T4: