Tyres of different size designations, constructions, and stages of wear may affect vehicle handling and stability. For best all-around performance, it is recommended that all tyres be of the same size, construction (radial or non-radial) and speed rating. If tyres of different speed ratings are mounted on a vehicle, then the same size, type and speed ratings need to be placed on the same axle. The tyres with the lower speed rating should be the determining factor for permissible tyre-related vehicle speed. Never mix radial and bias-ply tyres on the same axle.