What is the 3 tyre rule?
The 3% rule states that when replacing tires, the new tire’s diameter should not differ from the original by more than 3%. This guideline helps maintain proper vehicle performance, safety system functionality, and speedometer accuracy. The 3% tire rule is a widely used guideline in the automotive world. It says that the overall diameter of your new tires should not differ by more than 3% from the diameter of your original, factory-spec tires.