I've been running 32" tires for a couple years now. Goodyear Duratracs in 275/65-18. I did all the normal clearancing work to clear these - the rear heater hose and body seam mod; move the left front sensor wiring; cut back the frame horns at the rear of the front wheel wells, and some trimming of the front plastic fender liner.

The Duratracs proved to be pretty good in moderate wheeling; in snow and rain; but not so durable in rock crawling. In two years and 20,000 miles I cut two sidewalls and utterly destroyed the tread. You could literally tear pieces off with your hands, and the tires had become very loud and rough on the highway.

So time to upgrade. And you know, looking at it I think there's still a little room for more tire...



Which leads us to now. I'm currently running 275/70-18 Cooper STT Pros. They measure out at 33.3" - pretty much right on the spec sheet.

How do they fit? Pretty well actually. I haven't done any further trimming beyond what I had already done. With stock suspension they will rub the upper inner wheel well liners in front under harder cornering. With Johnson Rods installed, I could not get them to rub on the street unless I locked it into access height and then I got similar rubbing to running stock height (which you would expect).

Although these tires are theoretically the same width as the Duratracs, they are in fact a tiny bit wider at the should lugs. This gives just a tiny bit of rubbing on the front upper control arm at johnson rod off-road height with the wheel turned at full lock. Only one side will rub at a time and it's very minimal. I have a set of 3/4" spacers I could put back on, but that causes other issues in the front as it increases the swing radius when turning so I'm leaving them off and will live with the minor rub. It's only enough to touch a shoulder tread block and not the actual shoulder anyway so I don't suspect any issues.

I am also running the Proud Rhino bump stop extension kit and would recommend something like this if you were to run a tire this big. Although it won't matter in day to day use, if you have a failure w/o a kit like this, you will be fully immobile as the tires will be solidly into the wheel wells.

left front rub marks on wheel well


Right front


upper control arm touching sidewall at full lock/full lift

 

I should also add that they are louder than an AT tire, even an 'aggressive' AT like the Duratrac, at least new-for-new. My beat to hell Duratracs were louder than these are currently, but since I only have a few street miles on them so far it remains to be seen how they will be with some miles on them.

They do roll true and smooth, though a bit stiffer at least for now. I expect they will break in with a few hundred miles on them.

In short, I wouldn't recommend these for a daily driver, but if you wheel your rig hard they might be an option for you. As you can see though, this is clearly pushing the limits for fitment. I also expect there will be a further gas mileage penalty over the Duratracs (which were a penalty over stock) since the wheel/tire combo came in at 88 lbs.

 

Space for snow chains???

Our local mountains (Big Bear + Mammoth) have CHP checkpoints requiring you to chain-up before you're allowed to continue.

 

I would consider some wheels spacers to get that side wall out from the control arm

 

Don, You get an extra inch over the 275/65s. Cooper makes a Discoverer STT (I believe) in the 275/65 size....so, did you do this for the extra inch? Seems like more trouble than it's worth, but then again I don't know what kind of wheelin' you're doing. Maybe for the Rubicon Trail and other rock crawling that extra inch matters.

I only say more trouble than it's worth because I run 32s and haven't had to do much. Move the wiring harness and flatten the body seam. That's really it. IIDTool for an extra 2" clearance of course. No cutting or trimming though.

Also, being 3" larger than stock OD, are you not worried about or thinking about having to re-gear your diffs? What about strain on the components due to the larger angles on the driveshafts and axles?

PS - not trying to poop in your Cheerios. These questions are academic in nature. You're experiencing it, I'm not...that's why I'm asking.

 

First, NO to the chains. Of course, I couldn't run them with the 32s either. Even stock LR only recommended a special ultra-low-profile (and very expensive) chain set. The Duratracs did have the 'mountain snowflake' symbol, so they were OK for most situations but there are some cases where CHP will only allow even a 4wd with snow rated tires if it's running chains. The reality though is they generally just close the road to all traffic before they get to that point. Of course, I haven't been down to Mammoth, but I have done snow runs at Bald Mountain/Shaver Lake w/o chains and never had a second look. Possibly because it's not a resort area (?)

As to running spacers, I mentioned that I do have a set of 3/4" spacers that I had run previously as an experiment. I liked the ability to re-gain that extra bit of lost track width to help with stability and to keep the tires just a bit wider when on an obstacle to help keep me off the bodywork. However as mentioned, they increase the swing radius of the front wheels when turning, which causes other problems. They also prevent the tires from tucking into the wheel wells at full compression. So while I'd like to run them they're off for now. I may try them again, but they cause the fronts to rub at the rear of the wheel well and at the inner rear frame rail at full lock. On the other hand, they may reduce the amount of rubbing on the plastic fender liner, so that would be a bonus. I suppose a 1/4 or 1/2" spacer would be a better compromise, but I'm not planning to buy a set any time soon as they're not cheap. As I mentioned, the control arm only makes VERY light contact under a specific set of circumstances (max droop/max steering lock) so I don't expect it to be a problem. If that turns out to be wrong, then I will revisit the spacers.

The STT is the earlier version of this tire, and there are others that fit into the 275/65 (32") size that I could run. I didn't actually have to do any trimming beyond what I had already done for the 275/65 for these, though as you can see they will rub under the right circumstances. I'm not running any different driveline angles with these than with the 275/65 as I'm still running the same amount of lift (just the Johnson Rods with the GAP tool set to standard). They are heavier, so will wear wheel bearings and related parts faster, so that's a consideration. I'm probably going to have to do front half shafts before long, though I'm pretty sure they are the original 125K units in there now so that's not a surprise. The trucks are not particularly hard on front CVs despite the weight and I suspect that's down to the computer. I'm sure all of us have been in a spot where the truck simply refused to respond to the throttle - basically, it's limiting torque to save itself. If I were running a front locker there would be a higher chance of damage, but unless/until I kill the front diff that won't be happening.

And yes, I'm just trying to get a little more clearance. Is it worth it? Honestly, probably not for most people. I would hesitate to recommend it. I usually recommend a 265/65-18 for most people as it's the safest fitment. But I like to pretend my rig is a real rock crawler and chase guys with more truck than me, like next month's Rubicon run. And given the poor break-over and sill clearance of these rigs every inch helps. The extra sidewall will hopefully pay off, but until I get it dirty again it's all best guesses and hopeful wishes.

 

Oh, regarding gearing-
The truck still has adequate power and torque, though it's never been a hot rod. Ideally I would consider changing to a 4.10 gear to get back to the original over-all ratio, but I don't think anybody is selling alternative gearing for these diff at this point (?)

Again, if I should kill a diff in the future I'll look into this and an ARB front locker at that time but for now I don't plan to make any changes in this department.

 

This all makes sense. Can't wait to hear how things go on the Rubicon.

As for the tires and running chains. I have a set of Nokian Hakkas. The idea of needing to put chains on the LR3 with Hakkas on it is silly. I'd take the LR3 with snow tires that are good (Nokians, Mich X-Ice, Blizaaks) over any stupid Subaru with chains any day of the week.

Silly CHP...

 

I've only been turned around once, and not by the CHP. Entering Yosemite Park, December '08, in a new BMW 335 with summer performance tires. The rangers said nobody allowed without chains. I actually had chains from another car I had brought just for the hell of it but with the run flats the BMW didn't even have a jack and there wasn't clearance anyway. I pulled up to the parking lot and sort of fumbled around for about 10 minutes then took off anyway. Strangely enough I was able to drive everywhere in the valley just fine as well as up to Badger Pass (even though the road was 'closed') without dying. Funny how a little attention to driving in a normal sedan with summer performance tires will get you past an idiot with a 4wd. But then again I guess they have to assume the worst given the average level of driving skilled displayed by the american public.

 

AWD Bimmer at least???