Racking my brain on wheel backspacing, offset and width

I’ve spent countless hours researching wheel specs. Doing my best to understand offsets and backspacing etc. I’ve searched the hundreds of TW threads but brain still hurts. I promise I tried figuring this out first but I’m dumb apparently. Here it goes and shoot me later.

I’ve been contemplating 285’s for awhile but didn’t want to drop all that cash and the work involved and then not like the ride, issues and MPG drop and so on. Well I came across a stupid stellar deal on 4 almost brand new 285/75/16 Wrangler Duratracs (with stock Chevy wheels that I’m gonna sell). Thought this would be a good way to test the waters.

2015 SR5 4x4 access cab
I have a 2.5 inch Eibach lift, JBA UCA and CMC. I planned on keeping my stock 16” wheels but with this setup and everything my tiny brain could read I’ll most likely rub. So then I read countless hours on wheel spacers, pros and cons, what sizes and what brands. Don’t cheap out so looked at Bora and Spidertrax. Roughly around $250-$300. Well for that price I might as well buy new wheels with the offset and backspacing to not rub and sell the SR5 wheels.

I think I want the Pro Comp 69 Series 16” wheel. The offset is -12 with a backspace of 4. Only option is on a 8 inch wide rim and I believe I need the 6 on 5.5 bolt pattern. I honestly can’t figure out if these will rub or not and if not I’m worried a piece of paper will barely fit between the tire and UCA. Still racking my brain on proper alignment specs but that’s another time. Pasted the link below.

Can someone confirm or help me out? If there is anything else I’m missing or have opinions on etc. I hate that I posted this cause I know 100% of the information is on here but I just couldn’t for the life of me confirm. Maybe I should just sell the Chevy rims and tires for a profit and go watch a movie I don’t even know anymore.

https://www.4wheelparts.com/p/pro-comp-69-series-vintage-flat-black-alloy-wheels/9300

 

This link from TireRack explains wheel width (inside bead-to-bead), offset, and backspacing pretty clearly. Hope it helps.

https://www.tirerack.com/wheels/tech/techpage.jsp?techid=101

My Tacoma has 265/75-16s on stock rims, so I can't advise as to clearances etc. with upgrades.

 

Much appreciated. For whatever reason I’m still getting conflicting information on if I’ll rub the UCA or not. If I need spacers regardless then I’ll just keep stock wheels for now. Currently can’t justify buying both at this time. Thank you

 

Glad to help, even if I'm not much help!

 

75/16 may just clear if you force the camber on a -12 and don’t cut the wheel fully on a downturn bump at cruise speed. May need to ditch the plastic and hope for the best.

 

8” et -10 on a 285/75





No rubbing on the UCAs.

 

Don't even bother with the offset number. Backspacing value is what you need. 285/75/16 on a 16x8 wheel with a bs of 4" will not rub on the UCA. You will be fine.

 

Couple of links that may help you.

Wheel specs explained. This page also has a chart that will convert offset to backspace or vise versa, depending on wheel width.
Also beware, the use of wheel spacers will increase significantly the chance you will rub on the body mount while turning. Get the correct wheel with proper offset/backspace to reduce the chance of rubbing.
https://www.wheelspecialists.com/wheel-specs

This page does a good job of explaining wheel alignment:
https://m.tirerack.com/tires/tiretech/techpage.jsp?techid=4

For 285's an 8" or 8.5" wide wheel with a -12 offset should give you the best fit. Also your wheel should be hub centric.

Tacomas lug pattern 6x139.7 (6 on 5.5") with a hub bore of 106.1mm (4.18")

 

16 X 8 / 6 X 139.7 / 4.00" -12mm

17 X 8.5 / 6 X 139.7 / 4.30" -10mm

17 X 9 / 6 X 139.7 / 3.50" -38mm

these are specs for wheels made for tacomas,, hub centric, maybe this will help. they are from SCS wheels

i have new set of 17's in garage waiting for some 285's

 

I got a set of Pro comp 69 -12 offset, 4.5 backspacing in LA if you decide to go that route.

 

Sent you a message thx