Which of the following should never be mixed on the same axle?

Mixing bias and radial tires on the same axle can create significant handling and safety issues due to the differences in how these tire types respond to steering inputs and road conditions. Bias tires have a different construction, which can result in a stiffer sidewall and a different footprint on the road compared to radial tires, which offer more flexibility and better ground contact due to their design. This can lead to inconsistent performance, affecting vehicle stability, traction, and overall driving dynamics. When paired on the same axle, the disparity in tire flexing and grip can create unpredictable behavior, making it dangerous for the driver and passengers.

In contrast, while mixing all season and all-terrain tires, winter and summer tires, or standard and performance tires might also impact performance, the most critical issue regarding safety and handling arises from the pairing of bias and radial tires, making it particularly important to avoid this mix on the same axle.