There is a lot of debate and opinions regarding the right tyre pressure to run in your tyres and we can categorically say having done this for nearly 20 years that the biggest influence on tyre problems is speed. More tyre punctures and blow outs happen because of excessive speed than any other reason. Refer to our post titled ‘What Speed on the Gibb River Road?’
We also recommend you listen for any slow leaks every time you stop your car. Tyre Blowouts usually happen when a slow leak deflates the tyre causing the sidewalls to overheat or be exposed to the road and punctured by a rock. You might be unlucky and get a blowout from one rock on the Gibb but usually it is due to a slow leak.
Regarding actual tyre pressures, our recommendation for a hire vehicle with 2-4 people and average luggage is 35psi when the tyre is cold. Out of interest El Questro run 34-35 psi in their vehicles whether on dirt or on bitumen so 35psi cold is a good pressure that you don’t need to change throughout your trip. Just keep your speed down.
If you are heavily loaded or towing a heavy camper trailer then we recommend increasing your tyre pressures.