Thread: TYRE PRESSURE

How long is a piece of ....

You need to tell us about your Defender for a start. Is it a 90, 130, 110? Is it standard or does it have modified suspension? What do you use if for? People on the forum are very generous and helpful. But you have to help then understand you issue first.

Cheers
KarlB

These are standard tyres, and the car is legally required to have a placard with the pressures to be used, and it is also in the owner's manual. Not sure where the placard is on the Defender, on my 110 it is just inside the rear door.

I would use the placarded pressures as a starting point at least. These vary, as noted, according to which model you have, and according to the load carried and at least in the case of my 110, with the speed you are travelling, with lower pressures allowed for soft surfaces.

In my case I have found that normal highway driving light, I use 35/35, increasing to 45/55 at full load is suitable. In very hot conditions on bitumen, add another 5psi. For sand, and perhaps other soft surfaces, pressure can be dropped to 15/15 (or even lower if absolutely necessary), but keep below 60kph.

Higher pressures (within reason) improve steering and probably braking, and enhance tyre life and fuel economy, but give a rougher ride. More than 5-10psi above the placarded figures will offer no further improvement, just make it rougher. Best tyre pressures will vary very little with type or even size of tyre.

John

my 110 300tdi is 28psi front 48 rear (I run 40 unloaded) on 7.50r16- I don't adjust and don't get stuck
Brett

haynes figures
-90
750r16 28/40 psi

-110
750r16 28/48 psi
On my trayback with Michelin XZA I run 28/35 unladen then go to spec pressures for heavier loads.

I run 35/35 on road unladen and increase the rear only to 40 if towing or loaded. As the weight on the front doesn't change particularly whether loaded or unloaded, I dont see the need to increase the front. And I am what could be considered a slow driver in that I rarely exceed 95k's/hr.

Off road (dirt roads/rocks/sand) I reduce pressure to what I think works.

A very subjective thing as you will see.

wouldn't the trusty 4psi rule hold true

yep the 4 psi rule works...

the placard is a good starting point for your pressures.

G'Day matthew2,

Here's a thread on the same subject from earlier this year.

Tyre pressures for on road driving - 2004 110