Optimal offset/backspace for 33x12.5R15's on 15x10's?

[DJ Skillz]

Once I get my superlift installed, I'm going up to 33x12.5R15's on 15x10 wheels.
I wanted to see if anyone has had experience running these tires and what kind of offset is necessary so they don't rub.

Thanks in advance.

 

[4x4junkie]

4.5" backspace would be better to keep your wheelbearings happy with that size rim. Many guys use 15x8s with a 3.75" backspace (about a .025" decrease in offset vs. 15x10s w/4.5" BS)

As for rubbing, I've seen some reports of slight rubbing on the swaybar with the above tires/rims (which is generally harmless), though I don't have personal experience with them on the later (SLA-IFS) trucks, so here's a free bump to the top for your post.

 

[DJ Skillz]

Thanks for the reply. I might actually end up going with 15x8's. I'm hoping to find some used wheels and they're just so much easier (and cheaper) to come by.

I originally thought putting 12.5's on 15x8's would be a little bit of a stretch, but after doing some research, apparently quite a few people run that setup and don't have any problems. Makes my looking for wheels quite a bit easier.

 

[4x4junkie]

Within maybe the last decade or so a couple of tire manufacturers have changed their rim recommendation for 33x12.50 tires from 8-11" rims to 8.5-11" rims. Why they did this I don't know, but I don't think I've ever seen a 15" rim that was 8.5" wide.
(one part of me thinks it was a favor to wheel manufacturers to get people to buy new wheels, but who knows)

People have continued to use the 8" rims without any issues though (myself included). If you air down for offroad use, the tire beads are also far less likely to slip off with a narrower wheel.