« Reply #6 on: 12 December 2010, 10:25 »
Can someone please explain what ET sizes are all about. I'm getting GTD with the standard alloys but don't really like them and will prob change to 18s once need new tyres. What do I need to look out for in terms of sizing ?
7.5 or 8 inch wide, ET between 41mm and 51. Nearer to 41mm looks flush on the back but sit slightly proud on the front however visually fill the arches the best. 51mm is factory but sit in a bit far visually if you're a bit of a wheel junkie like me. Maybe 45mm is the best popular sized compromise using 225/40/18 tyres.
235/40/18s are a good width to protect the wheels from kerbs if using 8 inch wide wheels but do tend to stick out a bit when using a low (sub 48mm) offset on the front.
If you're a bit uncertain about about what offset and ET is all about have a quick google as there are some excellent guides online which explain in simple terms far better than I could attemp to type out. In short the lower the ET number the further out the wheels will sit in the arches. Go too far one way or the other and you will get either wheel arch liner contact or suspension or brake fouling. Wheel width will also have an obvious effect on how much offset you can get away with.

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