Tyre Pressure

Angler
It all depends on load.
When we get onto the dirt say in the cape we all pull over and have a look at the load and type of tyre.
For rough dirt roads corregations and hard sand once again depending on load.
A starting point of 26 front and 30 rear.
Then see how that feels.
Supposing you have a pump drop them further and see how that feels.
I run wranglers mtr 32*11.5* 15. When i have a small load I run the fronts at 19 and the rears at 24.
Then when the whole family is on board and all our gear fron at 24 rear at 28
And for very soft sand as low as 12 all round but no for long only when needed.
This also depends on load.

All the best
Eric

265/75/16 Cooper STT's................Patrol 4.2D

Bitumen 32 all round
Dirt roads 28 all round
Rough dirt roads 25 all round
Rough corrugations 22 all round

All sand 14 to 18 all round. There is bound to be soft sand somewhere along the hard sand track. Normally start with 18 and drop down if truck is labouring

Angler,
I run 38 all round with no problems on bitumen, I work my way down from there to suit load and road conditions, soft sand I don't go any lower than 6 that's got me out of any problems I've been in. As soon as I get out of the problem I'll inflate to something a tad more sensible, 10, 12, 15 something like that. Very much comes down to what you learn about your vehicle and how it reacts. I run BFG A/T's standard size. Max temp I allow the tyres to get to is 75 to 80 degrees C, if I get that hot I change something cause the pressure isn't right.
My opinions and experiences as usual.

G'day Angler, here's my 3 cents worth. I just bought a 2004 GU III Patrol 3.0TD manual, and had the same questions. 27,000k's and the rear tyres are nearly smooth in the centre. I have Bridgestone Dueller A/T D693's in 265/70-16 fitted.

I started by ringing the local Bridgestone dealer and asked the question, then the local Bob franchise, and surprise, surprise, surprise, got two different answers. Maximum pressure was anywhere between 50 and 65 psi.

Time to get technical. An email to Bridgestone Australia was quickly replied too. Maximum tyre pressure - 36psi !!! So from there I went and got the axles weighed (full fuel tanks and girlfriend, and myself in the vehicle, and it weighed 1,320kilo's - front, 1,240 rear) and from there it was simple math.

The equasion went like this (front) - weight (!,320) divided be 2=660. Maximum tyre load for the D693 is 1,120 kilo's@36psi, 36 divided by 1,120=0.032143. So 660 multiplied by 0.032143=21.2psi. Now I added another 5psi for high speed running (110kph) and with 26 psi (cold) in the front it steers nicely, doesn't roll about overly, and give a smooth and comfortable ride. The same equasion was done for the rear and I run 24psi (cold) there. This is the best starting point.

From here I will monitor heat build up - I am aiming for a 4psi pressure build up after an hour of highway running. If I get more than a 4 psi build up, I will increase the cold pressures by 2psi each time until I do. Conversely if I get less than 4psi, I will start dropping pressures.

Obviously loading the vehicle will change all these figures, but it does give a good starting point. Hope this helps. Cheers.