Question

Heavy trucks have 6-8 tyres why

Answer 1

While designing any vehicle a manufacturer have to follow ‘Motor Vehicle Act’. This act restricts the Payload capacity of vehicle based on the number of axles and tyres.

The following weights, are applicable while calculating the GVW of any vehicle-

(A) 9100 kg, in the case of an axle equipped with 4 tires,

(B) 9100 kg, in the case of an axle equipped with 2 tires that is a steering axle,

(C) 6000 kg, in the case of an axle equipped with 2 tires, other than a steering axle,

(D) 7700 kg, in the case of an axle equipped with 2 tires, other than a steering axle, that has tire widths of 445 mm or greater and is installed on a vehicle that is operated on a Maximum Weight Road listed in Schedule “C” to the Road List Regulations made under the Act;

For a example lets consider a vehicle with GVW 16T, in such vehicle you will find 6 tyres. Now lets see why? considering the front axle is steerable axle the maximum load it can carry as per the act is 9100 kg, in the case of an rear axle with 4 tyres it can carry additional load of 9100 kg.

Answer 2

Trucks have 6-8 tyres to reduce pressure on road.

Hope you helped.