What is the acceptable difference in diameter for tandem trailer tires?

The acceptable difference in diameter for tandem trailer tires is 1/2 inch. This standard is in place because maintaining a close diameter between tandem tires is crucial for proper performance and safety. When tires on a tandem axle have a significant difference in diameter, it can lead to uneven wear, reduce handling stability, and increase the risk of tire failure.

Having a maximum allowable difference of 1/2 inch ensures that both tires can rotate at similar speeds under load, minimizing the potential for swaying or fishtailing, especially during turns or while braking. This tolerance is designed to ensure that both tires share the load evenly, enhancing safety and extending tire life.

The other choices present smaller tolerances that do not align with industry standards, making them inadequate for ensuring optimal performance and safety in tandem axle configurations.