wheel backspacing

I have a '90 XJ with a 3.5RE lift. I have 15x7 AR steel wheels with 4.75 in. backspace. What is the recommended wheel backspace for an XJ? Also,what does "negative offset" mean? Thanks.

That's probably about the perfect back spacing for that middle ground of rubbing things like spring towers or control arms vs. rubbing fender flares. I would say anywhere in the 4.5 to 4.75 range for most normal sized rubber. I'm running 4.62 on a set of 15x8's with 33x12.50s that not only looks good but actually functions very well. Very little rubbing when flexed-up with ~6.5" of total lift.

I would agree with Lawless (see my earlier thread on 4.5bs) for the same general reasons. There seem to be more choices in that range for steel wheels, but for aluminum (especially one piece forged wheels under $200) it's almost non-existent.

3.75bs appears to be the norm, but that puts the tire (especially for 11.5 and greater widths) out from the hub quite a bit (IMHO) - and you would be faced with more fender/flares rubbing - especially at 3" of lift.

I believe the offset measurement is the relationship of the mounting surface (center) of the wheel to the centerline of its overall width (with negative offset being a "farther out (away from the hub) than center" indicator) - but don't hold me to it. Wheel measurements give me a headache.

Mike in NJ atriot: