I have a '09 f-150stx 4x4 with 17x9 rims +18mm offset and 5.71 backspace, I believe. What's the largest tire I can run on this setup? Thanks

 

315/70/17 with minimal rubbing with a level. Possibly at full turn on uca or lower plastic valance, which is easy to trim. If no level 295/70/17 would be the largest.

 

Ok thanks for the reply, I have a 2" levelling kit. Looks good then. Was looking at trail grapplers in 295/70/17, was just a little concerned about the rear of wheel well possibly rubbing. Again thanks for the good news.

 

Your offset is pretty mild so u will be good to go. If it were -12 or something u could have some issues.

 

Thanks again, you saved me alot of aggravation. I was worried about rubbing, looked close.

 

I think you are gonna have some serious rubbing if you try to fit a 315/70-17 (35x12.50). I think anything smaller will fit. A 305/70-17 (34x12.50) is probably the largest you can fit.

 

I disagree. His wheel specs aren't that much different than mine and I fit 315/70/17 easily without issue. Just went off roading a bit this last weekend and not a single rub. I have 8 inch wide with +25 and 5.43 inches bs. His may stick out half inch more than mine and hear the newer 09+ have slightly bigger wheelwells. Doesn't really matter as he sounds set on 295/70/17.

 

I'm not totally set on the 295/70/17 I just didn't think I could go any larger. I would like to fill the wheel wells as much as I can without having to cut or trim anything.

 

Well surprisingly the 315/70/17 are cheaper than the 295/70/17 in the tires I got. Pawpaw had some 17x9 wheels before the 17x8s on his old 04. He had 315/70/17 bfgs and his 9 inch wide wheels had 5 inches backspacing, which is why they rubbed a little. With yours having 5.71 and the positive offset, I think u would only possibly have to trim the lower plastic valance. Pawpaw help us out.

 

when I turn my wheels full lock it seems I have maybe an inch or less clearance from the rear of the wheel well. I'm not too worried about trimming the valance if absolutely necessary but can't do much on rear inner fender. That's my main worry.

 

PawPaw fit 35x12.50's by using an 8 inch wide wheel with 5.5 inches of BS. Deezstx may be able to fit a 35x12.50 using his wheels but he may have to do some trimming. Only way to find out is to test fit one. I think anything smaller than that will fit.

 

Thanks for all the help guys, I sincerely appreciate it

 

Let us know if u get them local and do a test fit with the 315s. I'm interested to know now if they fit without trimming or require minimal trimming.

 

I will more than likely be looking local. Will surely try the 315's and report back. Will be about a month or so, waiting for tax return to help cover cost. Again thank you guys.

 

Yeah, let us know if the 35's fit.