Hi Martin you should put this in its own post the hdi owner will be looking at it where it is the petrol owners may not read it! I'd say you need to change anything with a pully that is run by the belt ! I used a continenlal (contibelt) yesterday when I changed mine! my only advise would be to mark the belt and sprockets with tipex before you remove them and trasfer the marks to the new belt, his gives you a check that you have done it right! and after you have changed it turn the engine half a dozen times buy hand to make sure you fell confident all is well before starting the engine! If you get it wrong your looking at the potential of bent valves and damaded head/pistons part from here europarts are always good quality and well priced? Tom