I've got a set of almost new winter tyres 225/40 x 18 left over from when I traded my A3. I'm proposing to use them on the A4 with replica wheels 18 x 8, 42 offset. Present wheels/tyres are 17 x 7.5 (offset not known) with 225/50 x 17 summer tyres. Diameter difference is -2.98% so no problem, but will the increase width/different offset(?) be a problem. I'm being over cautious I know but a mistake with my A3 cost me a lot of money! Thanks in advance.