Advantages of 33" tires off-road

I'm currently running 31" KO2s and am wondering if folks have upgraded to 33"s? I am overall trying to make my rig more offroad capable when going over medium sized rocks. Thoughts?

 

Check out this video - great channel and multiple terrain types tested.

 

I went from factory stock 265/70R16 rubber to 255/85R16 Mastercraft Courser CXT's on my 2017 TRD OR Tacoma, the gains in performance offroad came mostly from the more aggressive tread than the size, though the size helped a bit with clearance/approach/departure.

I opted for 265/70R17 (31.5? 32?) Sumitomo Encounter AT's for my 2005 SR5 4runner. I kept up pretty well with some land cruisers on 35's and a couple TRD OR tacos on 33 and 32 inch tires this weekend.

My current experience is telling me that the combo of lift, tire, and skids/sliders is best, and I'd prioritize armor, then tires, then lift. Skids and sliders reduce the damage of unlucky events, tires reduce the odds of unlucky events, lift helps both.

 

Hey OP @xmt037
Good question, very popular question as well.
Some people stand behind sticking with stock tire size for vehicle geometry reasons, and to minimize stress on parts. This is true, but larger tires WILL give you more offroad capabilities. Wider tires better for mud traction, tall skinnies apparently better overall.

Highly recommend using the 4Runners.com "Search" feature. There's 32 threads on 33's lol
https://www.4runners.com/search/1475581/?q=33&t=post&o=date&c[title_only]=1

 

Thanks all. I realize bigger tires improve capability, but would 33"s be "stronger" (less likely to blow) over sharp rocks? That's my main concern.

 

No.

Airing down and going to a C or E rated tire is going to make more of a difference.

Edit: Just saw that you were on KO2s. If you are C rated, you can always go to E rated.

 

Thanks. The annoying thing is that I'm on 2-3h of freeway to get to trails each way. So trying to figure out the best compromise. How much more sidewall strength do I get with E rated?

 

C rated KO2 tires have a max cold inflation of 50psi vs 80psi for E rated.

Then there are the number of plies to the sidewall.

Ultimately, it’s about how sharp or a rock.

Sidewall is where the difference is, but you ultimately need to know the exact rock that will cause a problem - which is impossible.

 

You will get more height with 33's, so a little more clearance which is good. But some modding may be needed.

A good C load will do just fine. You could go E load but that comes with some baggage like the potential for extra rotational weight so you loose some MPG and some pep, little harsher ride as well. If you haven't had an issue with KO2's I am guessing you are fine. I have done some medium rocks with my Duratacs in C load and they have been fine. I would love a few more inches of height, but the modding needed is not worth it to me.

 

The 4runner is kinda crazy capable for a family wagon. Stock size ko2 will do almost everything 285/70-17s will do. But as mentioned, you’ll theoretically get better traction and flotation in the soft stuff. You’ll also get an extra 1/2 in clearance at the diff. Hey, half an inch is half an inch!

285/70s will effectively lower your gear ratio by a little bit. You’ll still be able go climb the same things, just your engine and trans have to work a little harder for it.

I have 285/70-17 K02s. If I’m honest, I like them mostly for how they look and feel on the 4runner. Second, I like having the bit of extra clearance, since I’ve dragged the diff and lower shock mounts on stock size tires. Traction wasn’t an issue with stock size K02s with most of my offroading, so I havent really been able to notice improvements in that regard yet.

 

Bigger tires = better surmounting of obstacles

There's disadvantages, such as fuel economy or the need for other mods to fit them, but generally if you are going off road your goal should be the biggest practical tire.

Beyond that, it's all personal preference as far as how many ply, tread pattern, brand, etc.