I've always understood that incorrect offset on an aftermarket wheel would cause steering and handling problems. But a lot of the threads here make it sound like it's more of an appearance issue, as long as the tire doesn't rub the wheel wells. Is my understanding of offset all wrong?

 

Messing with the track of your steering wheels can cause a change in ackerman angles and you could have anything from increased tire wear to problems with steering... but if it's just a few millimeters, it's not going to be that noticeable. Modifications to your car all come at a risk... if you're doing some serious suspension work, I'd have it tuned. Take it somewhere and check it after every adjustment, whether it be spring rates, camber, toe, track, etc.

 

35+ to 42+ max positive offset is good. I read somewhere that having more positive on the wheel makes it easier for the power to transfer down to the rims, something like that.