blow up right through the side wall (on my 240sx) after less than a year driving with them. They also increased the road noise by a ten fold. They felt so lousy and made so much noise it only took me one day to wish I never bought them. I bought two sets of Z wheels that both had brand new Dumblops on them and gave them to my daughter each time she wore them down. It took less than two years for her to wear BOTH sets down to bald and she doesn't even drive nearly as aggressive as I do. They were SP8000 and SP4000 tires. What a piece of sh!t!