WHAT TYRE PRESSURE 80 series

[LandCruiser1978]

Daft question but

I'm Running standard sized BFG mud terrains
What sort of pressure should i have them at?
They are at 32psi at the mo

 

[Rob]

I would recommend running a bit more than that, usually 40psi works best for most on non road tyres.

 

[LandCruiser1978]

40psi that high

i'll top up 2moz

 

[Beau]

Depends what sort of ride and fuel economy you want.

start at 35psi and work your way up from there.

 

[joinerman]

Iv'e got maxi's on mine & run them at 40psi

 

[Chas]

Got Cooper STT's on mine & run them at 40psi.

 

[LandCruiser1978]

i must say it is rather cumfy
It's like driving round in a king size bed
But would rather have better mpg

 

[Rob]

It will also improve the handling

 

[SimonD]

I'm reasonably happy with 36 psi on tarmac - BFG AT 265s. I allow for the 4psi rule to let the tyres go up to 40psi once running warm. http://www.lcool.org/technical/80_series/tyre_pressures.html

 

[karl webster]

I'm reasonably happy with 36 psi on tarmac - BFG AT 265s. I allow for the 4psi rule to let the tyres go up to 40psi once running warm. http://www.lcool.org/technical/80_series/tyre_pressures.html

Funny you say that simion.

I have always been aware that when you air up tyres you always do it when cold. I thought that when you add weight to a vehicle or they get hot they increase in pressure. Obviously from what you have just said when warm they do, do they when more weight is on them aswell?

Karl

 

[SimonD]

I measured mine before and after [cold/warm] and did see the 4psi increase. There are some things i've picked up. The larger the tyre the lower the pressure you can get away with. But the heavier the tyre the more pressure it needs to keep shape [works against first point]. The more weight the more pressure needed to keep shape of tyre. Higher speed means higher pressure - deformation of a tyre causes heat as tyre rolls so you want minimal deformation.

Some tyres dissipate heat less well than others and of course, terrain matters but this list is applicable to tarmac.

I've been told that manufacturers' recommended pressures are too low for touring trucks because of the extra weight.

Using the 4psi rule - cold v hot pressure - if difference is a lot more than 4psi the tyre pressure is probably too low.

So for tarmac i reckon most of the 36-40psi recommendations are pretty useful and the rest depends of ride comfort.

 

[LandCruiser1978]

2 weeks now with 36psi (cold)
and i can say oh my god what a change it's made to the mpg ..
Given me about 4/5mpg extra on a run

 

[Graham]

Hi Geordie,

Great news that the extra pump of air has saved your wallet some what.

Have you tried even more air?
Maybe try 38 psi, or 40 psi, ?

The 265 x 70 x R17 BFG AT were very well suited to 40 psi. regardless of the load carried.

Gra.