Thread: Tyre pressures, front to rear?

I run my disco tyres at the landrover pressure for highway use.
28psi front 38 rear though I find 38 a bit firm in the back when unloaded so use 36 psi rear wich seems to work fine and give a smoother ride

I have always abided by LR recommendations and run lower pressures in the front of my RRC. in fact you could probably run even lower with higher load rated tyres with a bigger internal volume than 205x16s.

Several reasons I can think of.

Final understeer rather than oversteer.
Less impact harshness on the front.
At full load the back has greater weight than the front.
Maybe something to do with resonant frequency ie softer springs are usually fitted to the front for the same reason. Perceived quality of ride is determined by the speed of deflection of the body , the slower the cycle the better. This is aided by tyre deflection. Tyres are an integral part of suspension design. I recall reading a dissertaion on the hydromat and there was a long discussion on the Ft/sec implications of soft springs vs harder without a hydromat.
If I recall from the dim dark past RRCs used to have a light load recommendation for rears lower than 38 AFAIR 34 or something. This disappeared later, probably because it led to people assuming light load when they had a heavy load.

So why would you NOT abide by the manufacturers recommendations. They have only been researching for 30 or so years to come up with the recommendations.
Regards Philip A

I dunno Phillip,, maybe its a money thing,,
uneven tyre pressures must cause differing wear rates/types,,
and that may cause an earlier than normal replacement.

Plus the fact I've run the last 14 years on even pressures

and while I understand THEY may know more,, THEY dont care about tyre wear at all.


and well,, 28 just seems a bit soft,,

Depends on the load.
I had a Vitara that recommended AFAIR 22PSI all round on 205x16s.
I ran it on 28 PSI thinking 22 was too low and it was UNBEARABLE on corrugations.
Dropped it to 20-22 and it improved 1000%.

On the very subject of Land Rovers, I had a set of 245x16 ATKOs on my 92 RRC until recently. I did 2 long trips to Flinders and up the Strez 2 years ago then Savannah way,Darwin, Oodnadatta with 28-30 front and 40 rear towing my 600Kg camper with drawbar weight of about 60kg. I dropped to 22/28 on the way to ABC bay and liked it so much left them there on the dirt to Leigh Creek.

When I got home inspection of the tyres showed the REARS both had small cracks on the raised line around the entire tyre while the fronts were perfectly OK. My conclusion is that the rears got far hotter than the fronts.

With regard to tyre wear, I find while the fronts get shoulder wear it is the rears that lose more MMs over time.
Regards Philip A

I run factory pressures and have done on all 3 Rangies, the D1, and County.

Re weights front to rear, even though the airbag diameters are larger diameter in the rear, to get the P38A level, there is more air pressure in the rear bags than the front (yes, I've measured them).

So does that mean the rear end is heavier?

I just did a bit of a search of the workshop manual and found this.

When loading a vehicle to its maximum (Gross Vehicle Weight), consideration must be taken of the vehicle
curb weight and the distribution of the payload to ensure that axle loadings do not exceed the permitted
maximum values. It is the customer’s responsibility to limit the vehicle’s payload in an appropriate manner
such that neither maximum axle loads nor Gross Vehicle Weight are exceeded.
Front Rear Total
kg (lb) kt3 (lb) kf3 (lb) I
Curb weight 980 (2160) 972 (2143) 1952 (4303)

Cross Vehicle Weight 2720 (5997)
Maximum axle loads 1150 (2535) 1620 (3572)

NOTE: CURB WEIGHT equals the minimum unladen vehicle weight plus full fuel tank.
GROSS VEHICLE WEIGHT equals the maximum all up weight, with the driver, passengers, payload
equipment and towing attachment load (where applicable)
GROSS VEHICLE WEIGHT CONDITION - the maximum axle weights shown are individual axle
loadings which allow for the fitting of optional equipment. The loading of both axles up to their
respective maximums MUST BE AVOIDED, as the overall maximum vehicle weight would then be
exceeded.

To summarise as the format of the chart was lost.
UNLADEN the weights of the front and rear of the car are almost identical at 980 KG front and 972 Kg rear. So the rear is NOT (significantly) lighter

The maximum axle loads are 1150 front and 1620 rear so the rear can be MUCH heavier than the front with a load on. If a load is placed in the "boot" it is all on the rear axle and may even lighten the front. The payload is 2720-1952 = 768Kg most of which will be on the back axle.
Regards Philip A

so,, given the weights are equal,, the lower pressure in the fronts are purely for ride quality??
or the higher back pressures are an assumption by LR of/for weight carrying??

I will run 28 for a while and see how things go,,,

The placard on mine (ES with 8" wide wheels) say front 28psi, rear 46psi which I have tried many times but could never get use to how sloppy the front felt. Might be the AT's causing a bit of it but I find 42 rear and 35 front feels the best combination for comfort, grip, wear and fuel economy. I rotate the tyres with the spare ever 5k or so then re-adjust pressure.