It depends on what tires, what cars, and how you drive la, cannot say every 25 k or 60k etc2. If you use high performance tires or even extreme ones with very soft tread compounds for maximum grip then they will finish up sooner but if you use low-mid economy tires aimed at durability then it can last up to 80k km, some even claimed to reach 100k km like the Goodyear Duraplus. Same tire also if you drive normal or slow then can last longer but if you drive often very aggressive then will eat up your tires faster. You use high performance cars also easier to chew up your tires, then heavier cars also may wear out tires faster.

Btw this is already very old thread risen up again from the death ha.