There’s no unified standard for this, mainly depends on tire brand, ply rating, working condition and driving habits etc. The period of shifting tires is different from the different working condition, based on actual wear. We recommend to shift tires in 20000 kilometers based on the actual wearing condition, without tire quality issues, no wearing exceed the “Wearing Mark”, and using the tire in normal working condition, right driving habits, regular vehicle maintenance. We recommend to make front/rear tires shift or cross tires shift to extend tires’service life.