4x4 Action Group

I've got the Toyo A/T Open Country II tyres on the Fortuner

Some input on tire pressures will be appreciated. I currently run them at the following

2.4 bar - General driving
2.4 bar - Well maintained dirt roads (almost as good as tar roads)
2.0 bar - Gravel roads that are not that well maintained (lose rocks or corrugation)
1.7 bar - Rough tracks
1.1 bar - Beach driving

I'm pretty comfortable with the above pressure, but the one I would appreciate some input on is the beach/soft sand one. Although 1.1 bar has been working just fine for me, I've always wondered what will be okay on this profile tyre. Never had a 60 profile on any vehicle before, so there is a part of me that is a little concerned about going too low. Last thing I want is for the tyre to climb of its bead. We've dropped a mates down to 0.6 bar for a recovery, but that for me is too low for general driving and turning in the sand.

These Toyo's are fairly new and a surprisingly good tyre. Just wanna make sure I run (and not ruin) them correctly

Living in Swakop, I always keep my tires at 1.8 bar. Good middle ground for pottering around town and going to the beach. Also perfect for gravel.

Extended Tar sections I pump up to 2.2-2.5 depending on load/distance/outside temps

Dunes/deep sand I always go down to about 1 bar. Probably overkill, but Never had any issues.

I agree with Manny on this one, basically run the same tire pressures on 17".

Tar 2.1-2.2
Sand 0.8-1.2
Rock/Gravel 1.2
Towing Heavy 2.2-2.4

But note each tire manufacturer differs, and don't trust the crap written on the door: Two methods to check.
1. Chalk test - Many videos on youtube
2. Weigh your front and rear of the vehicle, then have a look on your sidewall there is written for example max Pressure 350kPa, max load 900kg. Then you calculate how much weight is on each tire and scale those two values(pressure vs load) down accordingly. Works great with trailers and caravans as well, since people tend to overload them extremely!

I really cannot comment. I have proper profile wheels...

On the same 256/60/R18 I used very similar pressures. Gravel would be more like 1.8 and rocky tracks 1.6 but tiny differences.
One thing I can say is one the dunes I went down to 0.5bar when the sand got soft. I am pretty sure I could hear the rim spin in the tyre sometimes when boost braking up a dune but it kept its pressure. Never de-beaded.
I did a rocky track in Swazi that had sand and mud with 1.4bar and sliced 2 sidewalls in 2 hours so that was the wrong choice.

This was all Goodyear Wranglers

My snide comments from earlier aside...

I think pressures depend on tyre, vehicle, terrain.

Tyre - because they all have different characteristics. The Dunlop AT3's I had years ago had virtually no nubblies on the sidewalls. Deflating too much left them very vulnerable. Similarly, in my experience tyres with kevlar sidewalls etc need to be deflated quite a bit more in order to float properly.
Vehicle - because they also have different characteristics. My Patrol, for example, has different tyre pressures between front and back. The 4.5 Patrol also has that massive rear diff pumpkin...
Terrain - because the lower your pressure, the less ground clearance. Refer previous comment about that massive diff at the back of my truck.

That said, the pressures I roll with on my 285/75R16's are pretty similar to those already mentioned.

Tar - Front 2.7/Rear 2.9
Gravel - About F1.8/R2.0
Rocks and obstacles - Between F1.2/R1.4 and F1.4/R1.6. Depends on how rocky (that diff thing).
Sand - F1.0/R1.2
Dunes - F0.4/R0.6

I think the big thing is that I'll choose a slightly higher pressure depending on what I'm driving and deflate if I battle. It's faster and easier to deflate on a trail than inflate.