Tyre pressure

G/Day Kerry,...We run the Defender with750x16s and 45psi seems to be a good all round pressure with it.

Cheers Axle.

Kerry,

On Hwy driving, I would suggest 40psi all round.

Regards Will

Hi Kerry,

Everyone seems to have an opinion on this.
If you want to see what the tyre manufacturers and those who set the industry standards say then check out this website which does not contain any personal opinions, but information from tyre manufacturers and the US Tire and Rim Association. Most 4WD tyres in Australia are manufactured in the US or manufactured to US standards.

Tyre pressure, load and speed.

Gday Kerry,
With split rims, you need to run higher pressures than you would with equivalent tubeless tyres. Reasons are that you don't want the sidewalls to flex too much on the bitumen - it makes them run a lot hotter than tubeless and increases the chance of tube fatigue and sudden blowouts on the highway. So on the highway I usually suggest something like 38 front and 45-55 rear when loaded.

On gravel, you can lower the pressures a bit to improve the traction and the ride and might reduce the chances of tread punctures. But don't lower them as much as people with tubeless tyres would. I'd suggest pressures of around 32psi.

On sand, it is nice to lower pressures a lot because a 750R16 tyre is pretty skinny and needs the benefit of a nice long footprint. But you can get in a bind. If you lower pressures too much and use the power of a modern turbodiesel you can easily spin the tyre on the rim and with a split rim, this will pull the valve stem right out of the tube. But if your troopie is a 1Hz without an added turbo, you're unlikely to get this problem. So go down to any pressure you need in sand.

Always take 2 spares if running splits - if the tyres have been on the rims for a while, they can be a bugger to get apart.

Gday Kerry.
Sounds like you have split rims, so do I, put 50psi in the back and 40 in the front and you won't have any tyre problems, if the cold pressure rises more than 4 or 5 psi on the road then put more air in them.
In the 40 plus temps up north on bitumen the pressures will rise to about 60 and 50 but thats fine.
I was advised to put 40psi in the rear and melted two tubes, sudden blowout, before I wised up.
If you have BFG tyres with tubes in them make sure that the quality control stickers inside the tyre are removed before you fit it, they will eat a hole in the tube, I think its the adhesive on the label, I've had two flats with a label shaped hole in the tube, of course BFG don't recommend tubes in thier tyres.
Recently did 11000k trip including Birdsville and Oodnadatta tracks on the gibbers and I left the pressures at 50 and 40, I had no problems at all, I reckon the risk of heat damage is far greater than stone damage, the only problems I have ever had were due to under pressure or the labels as described above.
With wide rims and tubeless tyres the pressure can prebably be less but the above works fine for me.
I also use a Tyredog pressure monitor, a little sensor screws onto the valve stem and beeps at you if the pressure changes or too hot, well worth it, you can get 6 or 8 wheel kits to do the camper as well.