I had set of copper STC on Landcruiser Turbo 79 series about 5 years a go and got 10,000km out of the rear tyres and 10,000 out of a front pair and then 5,000km more on the rear i only just made it home as i had entire lugs falling off and i could see steel belt buy the time i got home. When i asked about if any warranty would be given and was told that it had been driven on a mine site so no. It was only a surface coal mine and I was averaging 1200km every week and only 200km on site every week. Luckily it was a work car so I was not paying for them but I don't think I be running with them again.