Tractive performance of tractor drive tyres: I. The effect of lug height

Abstract The tractive performance of five 13·6–38 tractor drive wheel tyres with lug heights varying from 0 to 75 mm was measured in a wide variety of field conditions over a 3-year period. No justification was found, from the standpoint of tractive performance, for operating with lug height greater than 20 mm when the tyres are to be used in British field conditions. Increasing the lug height beyond this figure did not increase performance in poor traction conditions and decreased performance in average traction conditions. Should lugs higher than 20 mm be required to ensure adequate tyre life, the increase beyond 20 mm should be minimised.