I have a set of wheels that are 18x7.5 +38. is it possible to have them machined to something higher so that it would be less stressful on my wheel bearings?? On the back of the hub it says et 38 and it also has a 42 and other numbers which make me think you can.. Any ideas or would someone be willing to try?
4 mm is not going to make that much of a difference. Also, you will sacrifice the integrity of the wheel by machining metal off of the mounting surface.