Thanks to everyone replying to my post the main reason i asked this question was because on a few occasions my car seemed to skip/jump whilst driving over a pot hole in the road at around 40-60 m.p.h. so is it possible because i dont have a staggered set-up this is causing the car to jump? well to find out im going to change the rear tyres and put 255/40/17 thus having a staggered set-up of 235/40/17 (front) 255/40/17 (rear) any other comments will be appreciatede thanks Nick.