Tyre preasure

[chriso]

Maybe a stupid question but here we go.
Of you guys that have them, what preasure do you run your Simexs (35 inch) on the road? I've got mine at 34psi and they still seem a bit hard.

Cheers

Chris

[UncleHo]

Are they Radials or Conventional Cross Ply type :?:

As a general rule it is unwise to run Steel Radials at below 32psi as the heat generated will cause belt separation, if convertionals 25psi would be a fair starting point, with a couple of pounds up or down depending on load and road conditions style_emoticons/<#EMO_DIR#>/smile.gif

[hiline]

i run mine at 40psi on road

[Slunnie]

I run mine at 36-38 on road.

[Maggot4x4]

35PSI

[JDNSW]

Interesting question - my 110 handbook has much higher pressures in the Australian supplement than the original handbook. The Australian supplement gives pressures in relation to speed and load, but the minimum is 35/35, max 60/65 for speeds over 120 fully loaded. Same figures are placarded. (These are on-road of course)
As far as I am aware cross plies are not approved for the 110.
Necessary tyre pressure is pretty independent of tyre size, but does depend to some extent on construction.

Last year a tyre repairer in Orange, having repaired a flat for me, told me that "No light truck tyre should ever be inflated below 60, don't believe what the vehicle manufacturers tell you".

[rick130]

<div class='quotetop'>QUOTE</div><div class='quotemain'>No light truck tyre should ever be inflated below 60, don't believe what the vehicle manufacturers tell you".
[/b][/quote]

and if I followed that advice, or L/R's tyre placard recommendation, I would have four tyres bald in the centre and full tread depth at the lugs.
Tyre case construction varies so dramatically from brand to brand and even within brands that a certain amount of common sense, observation and adjusting is required to find what works in any given application.

Example, I run 255/85/16 BFG MT's. I now run 30 psi in the front, and 30-34psi in the rear, depending on load for Highway, secondary roads, and 26-28 psi for mixed gravel/crook bitumen. Usually has 400+kg in the back (work truck) I started at 36psi all round and dropped from there, not to gain a cushy ride, but from observing how the tyre handled and reacted to the conditions I use it in. I've clocked up 45,000km now, no punctures, no obvious problems with the carcass, internal or external. (they were pulled off the rims 10,000km ago and swapped side to side)
The 235/85 Bridgestone MT's I used to use were run at higher pressures, around 38psi from memory, 'cause thats where they appeared to perform best on road.