tyre preasure

Hiya Trev

depends on the tyre but in sand down to about 10psi some may say 8psi...It also depends on the way you drive too...Take it slowly,dont spin the wheels the tyres will come off then...

If your stuck take out a few psi at a time,there's no hurry generally lol...

Heres a rough idea...





Goodluck

Trev&Ness ..Try a search on this - google & exploroz - ,has been on the forum not that long ago .

Depends on vehicle weight, tyre type etc but try taking them down to 25 psi and a maximum speed of 80km/h for a start and make a judgment. All tyres same pressure, van included. Check on tyre temperature after 15 minutes, raise pressure or lower speed if getting too hot.

You will not have bead seal problems down to 15 psi or lower unless you are traversing tracks with large rocks or deep ruts that exert lateral forces on the tyre.

so on a troopy running 75 psi on 16" split rims (16 ply conventionals) fully loaded with trailer one could drop the pressure to 25 psi on corrugated roads like the Tanami or Urandangi road (Plenty Hwy)? Is that the consensus? Then one wouldn't sit on 80 kms an hour, I presume. Same vehicle 15 psi in the sand?

This will be interesting!

and I hope it is. I would love some constructive feedback.

Thaks muchly for your input, gentlemen. There does seem to be a lot of variation between tyre pressures depending on the vehicle configurations, terrain and personal preferences. It is certainly an absolute that reducing tyre pressures in sand is necessary. I thought on hard terrain with high pressure the pressure in the tyres helped sidewall strength. To quote: "Correct air pressure in your tyres is as important as giving your engine a tune up. The economic benefits are perhaps even greater! With the right amount of air pressure, your tyres wear longer, save fuel, enhance handling and prevent accidents. The effects of not maintaining correct air pressure are poor fuel mileage, loss of tyre life, bad handling (perhaps even loss of control), and potential vehicle overloading."

Note how the air pressure increases with plus sizing to meet the load carrying capacity for the car. Perhaps the most overlooked factor is vehicle loading for trucks and 4WDs. Since these vehicles can be configured and loaded in many ways, the proper inflation pressure should be determined by actual tyre loads and respective tyre types. . Running 7.50 x 16 , high profile by definition, may require more air than radials which tend to have a lower profile (x/70 or x/80). I have run 40 or 50 psi with the 15" radials. The current tyres and pressures have contributed to long distance fuel economy and a rigid, safe feeling with driving control. And the high profile and high pressure have given over an inch lift. They sag a good half an inch at 50 psi.

I notice another member (Hughesy from SA) said:

Some 14ply Michelins I had could be run at 100psi and the current Bridgestones I have just put on are 10ply and have a max pressure of 80psi.

Adam's sign at the Pink roadhouse has loaded troopys with tubes on splits running 30 psi front and 36 psi rear as an optimum pressure for that stuff. This is 10 psi higher than equivalent rating for a large loaded 4wd on 16's.
He also says splits and tubes are the single WORST performing tyre combination going round.
Take it, leave it, mull it over, but the bloke has seen a few different tyre combos in his time.
Personally I don't think he's too far wrong.