Newby wheel offset confusion

I just purchased a 21 4Runner ORP and I’m looking at purchasing wheels and tires. I’m overwhelmed and confused about offset and backspacing. I know the current offset is +15mm but I cannot for the life of me figure out what offset/backspacing I need to chose to have a good fit. I’ll be getting a 2in lift and would like an aggressive look but still functional. I’m wanting icon alloy Rebound wheels and a 285/70/17 tire. Any advice would be greatly appreciated! I know this topic comes up a lot and I’ve researched all I can and still have no idea

 

Functional is subjective. Some people want functional with no work required, others will make it functional so it depends on the amount of work you’re willing to put in.
You’ll probably want to stay in the positive offset range to avoid any possible issues but you may still get them. Hit or miss, especially taking into account an alignment.

 

Do your research, figure out what lift, upper control arms and tires. Check with all to see what they recommend.

 

Those wheels aren't too extreme, so you should be fine running them with a couple of caveats.....

As mentioned above, you will need to make sure the backspacing works with your upper control arms (if you're getting aftermarket UCAs). Otherwise the 4.75" backspacing on the Icon wheels could rub. Stock backspacing is 4.5" for reference. Do you know if you're getting aftermarket UCA's? If so, what brand?

You will need to do the fender liner mod. It's easy and requires some trimming. Happy to answer questions on this process if you have them.

You will need a proper alignment with your caster in the +4 degree range.

 

As alluded to above, your best bet is to have the lift installed with your current wheels & tires. At that point you'll have a good baseline starting point to measure from for the wheels. Or, you could order everything up front and hope for the best. It really depends a lot on the lift you are planning...

 

@nimby i am not planning on getting new UCAs. The wheels don’t all have the 4.75 backspacing. If I purchased the ones with 4.5 backspace and -6mm offset would those work without messing with anything else?

 

Welcome to the forum.

 

Thank you!

 

Bottom line.......if you're adding larger tires and a negative offset wheel, you'll need to do some trimming. I recommend putting everything on first and then seeing where you need to trim so that you're not spending money on a body mount chop (for example) if you don't actually need it.

Here are a couple of ways to get that wheel/tire/suspension combo to fit. These are pretty common scenarios for most people adding larger tires and offsets that are lower than stock:

1) Do the fender liner mod, get aftermarket UCA's that work with your wheel/tire combo, and align your truck to +4 degrees of caster. This basically pushes your tire forward in the wheel well to avoid rubbing the mudflap and body mount. However, stock UCA's and a 2" lift will not allow you to get to +4 degrees of caster. That's why you would need aftermarket UCA's in this scenario.

-or-

2) Do the fender liner mod, do some trimming/heat gun molding/ or total removal of your front mudflaps, and possibly do a body mount chop. If you decide to not purchase aftermarket UCA's, your lift height/caster combo will have your tire sitting a bit more rearward in your wheel well. From this, you will most likely rub the mud flap and possibly the body mount. Trimming these areas will solve that issue.

Option 1 is easier if you're installing your lift at home, but it will be more expensive with the purchase of UCAs. The 4 degrees of caster has better road manners, IMO.

Option 2 is probably a little cheaper, but will require a competent mechanic to do the body mount chop......unless you're a metal fabricator and can do it yourself.

 

@nimby thank you so much for taking the time to explain some options! I’ll do some research on the options you’ve presented to me and see where I end up. I appreciate your advice!!

 

You're welcome! Hopefully this makes it easier to sort out.

Happy to clarify anything or answer other questions that pop up.

 

Hello all
I am new to the 4Runner world. I just a quick question if I can to put fuel rebel 17x9 -12mm wheels with a 265-70-17 Nitto tire on my stock suspension 4Runner without the rub or trimming. I’ve been conducting and I can’t find a clear answer so I want to see maybe if I can get some help here.
thank you