Understanding offset.

[Doc2012]

Im not up on wheels. Not very much anyway.

Help me understand this.

I’m running the 17x7.5 in the first pic.

I was running the stock 5-stars in the second.

So, the 17s have a 30mm offset.

The 16s have 15mm offset.

So I would meet an extra 15mm to make them sit in the same ‘spot’?

I was running 315/75/16 with 1.25” Spidertrax. No rubbing issues.

Bumped up to 37x12.5x17, and slightly rub the UCA.

If I added 15mm, that would negate the rubbing, right?

But, 15mm is over half an inch, which would need to be a 2.25” spacer, which they don’t make.

So I need to get some aftermarket UCAs.

Right?

Sent from my iPhone using Tapatalk

 

[St Runner]

Your math is good. A 2" spacer will put you a couple millimeters closer inboard than your original setup, which really should not make a difference. I did not compare the actual tire size head to head which under low pressure could make a bigger difference

 

[Mark_BC]

https://www.1010tires.com/Tools/Wheel-Offset-Calculator#

https://www.wheel-size.com/calc/

 

[rkntoy]

Current wheels have 5.43" backspace and new have 4.59" backspace. So if you want the same clearance you would need a .84" wider spacer. So a 2" is onlu going to decrease your UCA clearance by .09". I have some shaved UCAs for really cheap if you need more clearance.