bigger alloys

[billy g]

Hi, can anyone offer advice here, I have 17x8j alloys on my 2009 A4 2.0tdi, with 245x45x17 winter tyres, I would like to put on 18 x 8j rotors, with 225 x 40 x18 summer tyres, would there be any rubbing or handling issues and would it affect my Speedo at all. My car is an a4 2009 2.0tdi se. Ps, do you think 45 rather than 40 on the 18's. Any advice gratefully received. Billy g.:biglaugh:

[Embisix]

You won't have any rubbing problems as long as the offset is correct. Are they OEM rotors or replicas? 225/40 R18 will, however, throw your rolling radius out a bit, resulting in your speedo over-reading slightly, check this site out for comparisons:
Tire Size Comparison (http://tire-size-conversion.com/tire-size-comparison/)

The correct tire size would be 245/40 ZR18, this gives the exactly the same rolling radius as your existing winters and is (I believe) the size fitted to B8s with 18's.

Why are you thinking of going narrower for your summer tires? They will offer slightly less grip as a result and might look a bit 'skinny'. 225 section tires are the standard width for SE Spec 17" rims....