I have the pro comp extreme at's and can't fault them one bit of and on road. I have done around 70000 km and still have heaps of tread. Not as grippy in the wet as I would like on road. The bloke that sold me on them said that the coolers are warranted for the 75000 or so as long as you don't take them off road don't know how true it is though, he also said that the pro comps are warranted for around 65000 from memory. The Km's could be a bit out but would be around there from memory.