Want to move from 265/70r18 to 285/65r18...possible?

I currently have XD Monsters, 18x9, +18 offset and 5.71 Backspace. Tires are General Grabber AT2 P265/70r18. I have Billies @ 2.5"

I had to trim the front fender slightly and I was getting slight inner sidewall rubbing on the chassis. No rubbing on UCA. There was a 1/4" of space there. I added a 1/4" spacer plate and that solved the inner sidewall rubbing.

I want to get BFG ATs. I had my mind made up to get 275/65r18 as they are pretty close in side to my Grabbers. I shouldn't have to do any more trimming. But deep down I want 285s. But I really think it would be a very tight fit. If I had those wheels in a -12 offset, I doubt I'd have any issues. I don't think my current rim will allow for a 285 comfortably. Based on my research, my Grabbers have a 282mm section width on a 9" rim. The 285 ATs would have a 297mm section width on a 9" rim. Thats a 15mm difference, or 7.5mm on either side, ie, 1/4". But I know math translated to real world application doesn't always jive.

According to the manufacturers specs, my Grabbers are slightly taller than the BFG 285's. Its just hard to figure the difference in width on the rim.

What do you guys think?

 

Have a look at this post from the DSM thread.

http://www.tacomaworld.com/forum/2nd-gen-tacomas/19409-desert-sand-mica-tacomas-3.html#post1304931

I PM'ed C0astie years ago about his truck and he said his wheels/tires are perfectly flush with his fender. He didn't know the offset of his rims. But I would guess they are the same offset as mine, +18, as they are flush too. -12 would stick out by 1.5". His lift is 3", mine is 2.5" Does that help in my post above?

 

You might rub on the UCAs at full lock with 285s and +18 offset. MIGHT, not sure on this, but most people recomend 0 to -12 offset for 285s

 

http://www.discounttiredirect.com/direct/brochure/info/tmpInfoTireMath.jsp

 

After doing more research, I found this thread where a user here put BFG AT 285/65r18s on his STOCK rig with only some trimming.

http://www.tacomaworld.com/forum/wh...ta-ko-285-65-18-chrome-xd-monster-3-lift.html

Specifically post 14
http://www.tacomaworld.com/forum/wh...-18-chrome-xd-monster-3-lift.html#post2664963

With my 2.5" lift and 1/4" spacer, I should be able to run that size with some little extra trimming perhaps.

 

You might be alright. Every truck is different. I have 2.5" of lift and i rubbed like crazy with 285/70/17, needed cab mount chop for normal driving, cut the fender flares front and back and i still rub when offroading. I have wheels with -10mm offset though, and LR UCAs. I just think you might be close to the UCA

 

Your tire size is pretty much the same as the 285/65r18s. Same height as my current 265s. Given your LR UCAs, -10mm offset, it is hard to compare your setup to mine.

I may have a local tire dealer on board to test-fit a 285 when he gets some in. I may do some pre-trimming beforehand. Wouldn't hurt anyway even if I go with 275s.

 

Ok, so took one of my summer rims with a 265 out of the garage and put it on the truck with the sole purpose of measuring clearance. Only limitation was I couldn't check clearance during flexing.

First, the section width of the tire is 11 5/8". I laid the wheel down on a flat surface, laid a long straight-edge across it and measured from the straight-edge to the surface.

I chose the left front wheel to test. I also put the 1/4" spacer back on.

The first picture is the clearance between the tire and the UCA, wheel pointing straight.
The second is of the front inner fender where I had to do some minor trimming.
The third is the wheel cut hard to the right. Not much clearance to the UCA.
The fourth is wheel cut hard to left. Decent clearance to the UCA.
The fifth picture is half turn to left, a nice gap between tire and mudflap.

I really have reason to believe I can run BFG AT 285/65r18s. I hope to find out soon.

 

Ganna be close! Remember that the sidewall is wider than the treads, and the 285 is taller than the 265s, so even though in theory you will only be 10mm closer to the UCA, the bulging part of the sidewall will be higher up closer to the UCA

 

According to the tire specs, the 265/70r Grabbers are a fraction of an inch taller than the BFG 285/65r. So it shouldn't add additional height.

 

I see, i forgot you had 265/70/18, not a very common size, at least here anyway.