do the 12.5s really cut down that much more on gas mileage than a 10.5? i want to still do decent with gas, its bad enough as is, but i dont necessarily want to sacrifice styling either.

 

For the average person, I doubt there would be significant (i.e. noticable from the seat of your pants) difference between the two in terms of actual traction/performance. There may be some gains in power/mpg with the 10.5s, and obviously they will have a noticably different look, but I doubt you'd notice much of a difference in traction.

 

Bagger- that wriet up is awesome. I learned a lot.

Like I said, I gained about 1 mpg switching from 12.50's to 10.50's. That's probably coming froma combined loss in weight, loss in width, and loss in profile and wind resistance.

I thought they looked stupid at first, but they grew on me as my idea of what a "cool" truck was changed. Before I always thought bigger and wider was cool, but now I've kinda decided what gets the job doen most efficiently is actually cooler.

 

got any pictures with 33x12.50s on your rig

 

I have a set of BFG mud's 33x10.5 with 4500 miles on them for sale. I also have the spare (never used). Let me know if you are interested.

 

I have been debating for weeks (even months) on what to get:
33x10.5 or 12.5?

1) I have 15x8" wide rims so what would be an optimal fit?
2) Which would be better for airing down (on my size rims) without loosing its bead?
3) What would have the longer tread life and wear most evenly on payment? I've read and been told the oppisite.

I know a lot of you guys are running 33's so more opinions and advice would be appreciated.

 

For off-road use, airing down, etc., 12.50 tire on 8" rim is ideal. For on-road use and better tread wear the 10.50 would be the best fit, that is within the rim width range recommended by the mfg. I run my 10.50s on 6" rims and have some 12.50s on 8" rims.

Why?

For off-road use it is best to have the tire ~4" wider than the rim. This gives a better sidewall bulge, tire protects the rim bead from rocks, dirt and mud, and the tire is trying to push outward from the rim bead, making it able to air down farther.

For on-road use, you want the rim width much closer to the tire width, keeps the sidewalls straighter and that keeps the tread flatter to the pavement. Tires corner better, treadwear is more even and lasts longer.

 

I'm glad someone brought up this post becuase I had asked Jim about it a few days ago about the differences in lift height requirements for either size. It makes sense that wider tires have better traction, hence Dodge's old saying "Wider is better." But it also makes sense to use a skinny tire for contact to the ground during mud and snow.

 

The whole contact surface thing seems to be (is) the most agreeable. What i'm mainly concerned about is tread wear on pavement and also like you mentioned; lift height requirements. Theres a guy on the forum, 'Dublin' thats running 33x12.5 on a 1994 Runner with STOCK suspension. I've read stuff where people say that on a 2nd gen, you "definitely need some lift" but they never any mention anything about back spacing which of coarse can play a big role when it comes to rubbing. So....

Does anybody have anything to add? Experience, opinions?

 

33x10.50 on stock wheels (15x7 w/ 4.75" b/s) will fit with an inch or so of lift:
http://www.4crawler.com/4x4/ForSale/BodyLiftKit.shtml
Or if you are not averse to trimming sheet metal, have at it. 33x12.50 on 15x8 rims will require more lift, since the 8" rim and 12.50" wide tire will push the outer edge of the tire 2" farther out from the body, wider tire = wider arc while steering = more likelyhood of contacting the fender/firewall:
http://www.4crawler.com/Diesel/Tires...ningTrackWidth
I had a buddy with 33x10.50 on stock wheels, 2nd gen 4Runner w/ 2" body lift, he had to do no trimming at all, no rubbing.

 

Can anyone else (preferably with experience) comment about what you'd get on a 15x8" rim? ....12.50 or 10.50? I'm buying new tires today or tomarrow and i dont want to make a $600 mistake.

Oddly enough, yesterday the assistant manager at Big-O Tires told me 12.50 wont fit on a 8" wide rim ...and hes supposed to be an "expert"

 

I have 10.5's on 8" rims and they only rub under extreme compression and steer on the front with a 2" body lift.

 

Officially, 12.50 tires only fit about an 8.5"-11" wide wheel, according to the tire mfg:
http://www.bfgoodrichtires.com/asset...rain_ta_km.pdf
A 10.50 is supposed to fit 7"-9" wide wheels. So many tire shops go by the tire mfgs. recommendations, probably for legal reasons. This is also mainly aimed at on-road use, you'll get better tread wear and better handling with wheel/tire widths in the recommended ranges.

I like running tires about 4"-5" wider than the wheels, so 10.50 on 6" rims and 12.50 on 8" rims for off-road use. Lets the tires air down better, less likely to lose a bead, sidewall bulge helps protect the rim of the wheel from damage. I mount my own tires so don't have to hassle with the tire shops, but if you can find a shop that will mount up whatever you bring in, then do the 12.50 on the 8" rim, at least assuming you intend to take the truck off-road a fair amount. Otherwise get the 10.50s.

 

12.5 - I've all weekend in the desert with 33x12.5's in 2WD. sand dunes, trails, everything no problems. The extra width really pays off.

 

Just wanted to respond and post some pics I just took of my rig w/ 33s:



Can you see the Downey's?


The rear tires were rubbing on the bolts that held the mudflap in place, so I took them off. Also, the front tire rubs in the fender at full turn.


I think a sway bar disco would help with the articulation. All in all, these 33x12.5x15 tires are AWESOME!

 

Good read
funny comment on wider vs. narrow
3. For a vehicle relegated to pavement work and cruising, then the “balloon” tires are a good choice.

 

I have the best of both worlds - during the week and my 70 mile per day commute - I run 31 X 10.5 X 15's I have another set of wheels that I mounted 33 X 12.50 X 15 on that are strictly for wheeling purposes.

I haul them to the campsite and swap my wheels before wheeling - they are already aired down to 15 lbs and when I'm done - I swap wheels and go home.
Gas mileage sucks with the 12.50 tires !

Just my 2 cents worth

 

I'll second this, it is much better when aired down and less likely to lose a bead.

 

I'm having the same dilemma with which tires to get so I'm thinking why not 32x11.5? I'm not planning on buying gears in the near future so I'm assuming the 32's will be a little more bearable power-wise and gas-wise (i've got 4.10's) until I re-gear. They also have a noticeably wider stance than the 33x10.5. You can also use the stock 15x7's. Only loss is 1/2 inch of ground clearance, which I'm not sure I would notice that much since I dont generally run super tough trails. (my truck is stock) Do you think I'll regret not going straight to 33's from the 30's I'm currently running?

 

32x11.50 is def. alot easier to find in alot of brands than 33x10.50. If I had 15x7s and not 15x6s I'd proabably have 32s already.