best "normal" pressure Bridgestone A/T tyres?

Martijn, there is a 4PSI rule that you can use to establish the base tyre pressure to work from. It works like this, check the tyre pressure cold. Drive on the bitumen for an hour (highway running), stop and check the tyre pressures. If the tyre pressure has increased by 4psi you will be close to the correct pressure to run for your tyre/axle load and speed combination. If it's greater than 4psi, you need to run more pressure. If less than 4psi, you have started too high and need to drop the cold (initial) pressure.
My Base Air Pressure is 34 PSI (for my old Dunlop Grandtreks).
For driving in conditions other than bitumen, I drop my tyre pressures according to the following,

If I go off road in sand, - I air down to 20 - 22 PSI.

If I go off road in soft dirt / gravel, - I air down to 28 PSI.

If I go off road in stoney ground, - I air down to 30 - 32 PSI

Once you establish the Base for your vehicle, then you can air down in similar proportion to the above.
Hope this helps.
Mal58

Phil Burnard TFS Engineer with Bridgestone suggests pressure is adjusted to meet load of and on vehicle and speed conditions.For a patrol unloaded he feels 32 would be more than adequate for highway.Loaded heavily may need 36-38. On stoney rough road he suggests to reduce pressure slightly but only if speed is reduced eg under 60km/h when pressure could be 28. I however like the suggestion of the prior response and that of many previous respondents in the forum who have a proven track record regarding the 4psi rule which makes sense and I will adopt that approach on my pending trip.

Martijn,
I normally run 32 front 34 rear on my patrol unloaded and light load. Increase by 2 when fully loaded then apply the 4psi rule, always works a treat. My dealer inflated to 40psi on a pre trip service, felt totally uncomfortable and when I checked the pressures I was running 46. Quickly dropped them and no problems

A trick I use to ensure correct and even wear of WIDER tyres is to smear a strip of silicon rubber across the tyre at a certain point (eg use the tyre valve as a marker) leave it to harden overnight and check how the silicon wears off after 10 or 20 ks If the edges still have silicon on the surface of the tread they are overinflated if the centre still has silicon they are underinflated, also handy to check for scrubbing. Be scientific about it and you can work out best pressures for your laiden and unlaiden vehicle I expect you will find that if you check hot and cold pressures it will all tie in.
Hope this helps you all

kezza