Is it permissible to mix bias-ply and radial tires on the same axle?

Mixing bias-ply and radial tires on the same axle is not permissible due to safety concerns. Bias-ply and radial tires have different construction methods that significantly affect their performance characteristics, such as handling, traction, and stability. When combined on the same axle, these differing characteristics can lead to unpredictable vehicle behavior, especially in emergency situations or during turns.

The safety standards in place, like those required for inspections, emphasize that uniformity of tire type on the same axle is crucial to maintaining proper control of the vehicle. This uniformity helps ensure that all tires respond similarly under various driving conditions, thereby promoting safer driving practices. Therefore, failing to meet this requirement results in failing the inspection.