So, just to clarify, larger offset moves wheel+tire inwards (until tire eventually rubs on inside of wheel well and/or wheel rubs on brakes). smaller offset moves tire outwards (until tire eventually rubs on outer finder lip or sticks out, depending on springs and ride height etc). PS: I used to have a full race prepared 96-SS Camaro, and the STOCK rims (with STOCK SIZED race tires) would rub (under extreme race cornering) on the inside wheel well and our standard "fix "was to take a hammer and hammer in that particular section of the wheel well.
Wider wheel (rim) does not directly change anything, but if you have wider wheel you typically also put on wider tire, hence both inside and outside edge of tire are then both further inside and outside. Get a wide enough tire and you could rub both inside and outside, especially under cornering load (street "posers"sitting in "shine-and-shows" dont matter).
Of course, the effects are cummulative. If you change the offset, and you also change the wheel(tire) width, you get a combined change.
There are also effects on steering geometry and tire wear pattern, load on bearings, etc, but these are usually secondary considerations (except in very extreme cases, and/or if you drive the car in serious perfomance cornering situations).
2010 XRS in Barcelona Red
Last edited by searle; 02-04-2010 at 03:13 PM.