What is the maximum tread pattern difference allowed between new and old tires?

[DiCayden]

The tread pattern difference between new and old tires should not exceed 3 millimeters. If the difference exceeds 3mm, it is not recommended to mix new and old tires, as this indicates severe wear on the old tires which should be replaced. Tires are the components that directly contact the road surface, affecting both driving stability and safety. Therefore, tires should be replaced immediately when needed. When purchasing new tires, always check the production date. Unused tires have a shelf life of three years - tires older than three years from production should not be used as they deteriorate even when stored. After installing new tires, it's essential to perform dynamic balance tests on each wheel.