Sorry, no such thing as ideal tyre pressure!! it depends on the load, for comfort you can go to 30 psi but expect higher fuel consumption and higher tire temp!
I personally run at 46psi empty, but go to 40psi fully laden.
Saved this from the forum some time back - don't know who wrote it but it's good advice (not my article, in other words).
What's the 4psi rule?
The “hot” tyre pressure should be 4psi higher than the cold tyre pressure. For example, if I if run my tyre pressures at 35psi (measured when the tyres are cold) and measure the pressures again after an hour or so on the road, they should be at 39psi: that is 4psi difference between the cold and hot pressure.
If the hot tyre pressure is more than 4psi higher than the cold pressure, then start (cold) pressure was too low: if the hot tyre pressure is less than 4psi higher than the cold pressure, then the start pressure is too high…
I use the “rule” for any tyre in any given terrain – I’m happy with the results anyway. For the record and at the risk of igniting a fierce debate, this means my tyre pressures are:
• Daily driving: 33psi
• Loaded and with camper: 36psi front/38psi rear
• Fast unsealed road: 28psi (Oodnadatta or Tanami Tracks and their ilk)
• Slow unsealed roads or tracks: 26psi (High Country for example)
• Off-road: (usually) 18psi unless its sand or snow when I always run at 15psi
That all makes me look more anal than I really am, in reality I set them once and then check them daily: if I go the High Country for example, when I leave the tar at the Sheepyard Flat turn-off, I re-set the tyres to 26psi and don’t air-up again until I hit the tar again.
i have run 28-30 in my Patrol for the past 10 years with no tyre issues. My current set of cooper AT are up to 106,000km and still have a little life in them yet.
I got 90,000km out of the first set of coopers which included a cape York trip, fraser island and many high country trips.
On long road trips with a full load i will increase the tyre pressure to 36 at the rear and maybe 32-34 front but for every day driving i use the pressure listed above.
I run 36psi which equates to 40psi when hot...for sealed roads.
BFG 285 75 x 16s should nt have any bagging so I am told by the tyre dealers.
Anything too low will generate heat in the sidewalls and hence failures..but I run as low as 34s on unsealed gravel which is 38psi when hot and reckon this is their sweet spot.
2 trips up the Gibb with no tyre probs is good enough proof for me...
The only problem I do get is accellerated wear at the higher pressures but I can live with that and it helps with the fuel consumption figures.
Just my 2 cents worth...