Kkline

I’m hoping I can get some advice on recommended tire pressures when I go on my next off-road trip. I’m heading to the badlands off-road park in Indiana and I’m wondering what guys with similar setups run for pressure off-road at slower speeds. I’ll be doing mostly crawling up sandy hills and over rocks and a little water/mud but not heavy mud.
I have 35x12.5” General Grabber X3’s on Method 17x8.5” rims.

I was was thinking of starting at 20 psi with about 600lbs loaded (me plus gear and added accessories). I run 35 on the street normal load (600-750 lbs passengers and cargo), 40 when I have a heavier loaded truck (1200lbs).

Kkline

Scott91370

I can tell you I wouldn't go below 20psi.

Florida_F150

If you're going for comfort, you can lower the PSI a little bit, but it looks like you have excellent tires. I'm not sure you'll need to air down from 35 psi much, if at all. I run 37" Nitto Ridge Grapplers at around 38 psi, and I don't air down at all. I aggressively off-road all the time over rocks, sand, through mud and water, etc. I've not had a problem at 38 psi. Setting your truck up for each scenario will probably be more important than the PSI. For example, if you have a rear locking diff, knowing when to turn it on / off. Turning off Traction Control before going in the mud and sand, etc.

Kkline

AK4wheeler

Airing down for off road depends on your vehicle and terrain you are about to transverse. I have found that airing down to 15-22psi is perfect for mud and sand. Airing down to 10-15psi is great for rock.

AK4wheeler

jp360cj

I doubt you'll notice and difference at all until you get to 20psi or less, so that's probably a good place to start for general trail riding. If it's more rocks, then I would start around 15 psi.

FWIW, I ran 20 psi on the beach last year and did fine, but I would have gone lower if I had known the air up stations were so close and so fast. I run 285/70/17 Duratacs on 17x8.5 Raptor wheels. On my Jeep, I run 15 psi on the beach and 10 on the trails.

Kkline

Clubsoda

I have 275 60 20 ko2s, i run 50 psi normally, 55-65 when towing (65 is max psi of tire - use that when I tow my travel trailer on highways/roads, 55 when towing my trailer up bumpy logging roads at slower speeds). If I'm traveling mountain highway passes in winter time with a blend of snow/ice/dry roads, ill drop it to 35-45. Off road, using 4x4 low/high, going 5km-40km/hr I'll go down to 20-25. On my old dodge dakota with 17" rims I would go down to 15. Traction is noticeably different from 50-35 psi off road. I love the look of the 20" chrome rims, but I'll be looking at some 17-18s next summer..bit of a better ride off road & more sidwall.


On your next run, start with higher psi for a couple of obstacles, drop your psi and try it again - experimenting with it is half of the fun

ZipperWood

Experimenting is a huge part of it. Not all trails or tires are created equal. I do a lot of desert driving in the UAE. Even along the same stretches of desert we use a lot the sand changes from trip to trip depending if there had been high winds for a few days previous or if there was fog in the morning. we go from sand so soft and powdery that dropping anything invariably means a 20 minute search, to the same thing a week later where there is a thin crust over everything and sand seems almost moist, until you get about 2 inches down. i was running Nitto Terra Grapplers 295/60/20 at about 25 pisi most of the time. I honestly found that dropping to about 15 was almost night and day. Tires changed recently General Grabber X3- 35x12.5x20 and after a bit of playing at different pressures I am running great at 20. Having a frame mounted air compressor and tank makes airing up much easier. Just remember..... the lower you go the higher chance or rolling the tire off the rim when turning on harder surfaces. See it happen a few times, luckily not to me....