I want to start airing down when going off road. What is a safe PSI?

 

I've gone down to 15 PSI on all fours for about three days and all seemed fine.
I have a compressor to bring them back up to 35 PSI when heading home on the highway

 

The 2 adavantages to lowering air pressure are increased foot print and flex of tires (better traction and floatation)and improved ride especilally on washboard roads.

I usually run between 25-18 psi depending on the conditions. If you get stuck in sand you can let out even more air untill you get traction

What size tires are you running?

It sort of depends on the terrain and how long you will be off-road and how heavily loaded the truck is and if you have an air compressor. You can run on the hwy for short periods at low speeds with reduced air pressure

below 20-18psi the sidewalls are are a little more vulnerable in the rocks and the lower you go the more chance of teh tire comming of the bead if teh rim.

 

In the mud I run 18 PSI and get great traction. Don't have a compressor yet so I head straight to the gas station for air afterwards.

 

I run down to about 18psi in sand up to about 25psi.

 

yea, thanks for that advice 3hummers (who told me to run 18 PSI)

 

It depends on your tires, wheels, and vehicle. Honestly, 18 PSI is high even for the stock Good Years.

To find the ballpark "aired down" pressure you should run on your vehicle with your tires and wheels, measure the distance from the ground to the bottom of the rim. Let air out to reduce this distance by 25%. Check the pressure and this is your "aired down" pressure.

Now make adjustments based on your tires and the terrain. In sand you should be safe. If your tires have a weaker sidewall (your aired down pressure is above 10 PSI) you will want to run a higher PSI in rocky terrain to reduce the chance of sidewall puncture.

 

Its pretty much all sand where I am and usually run 15 front and 12psi rear on 285/75 BFG A/T's. Works quite well but have popped a beada few timesup front but that was mostly down to driver error. On the graded unpaved roads and rough gravel tracks 20psi all round.

 

If your serious about off roading look into getting the PowerTank, I bought one and can atest that it is the best/fastest way to inflate your tires back up. 1 10lb. tank can fill all four tires on 5 Hummers. It doesn't cost that much to fill up with CO2 and you can run air tools also.
I run my tires depending on conditions at 20psi, if you buy tires look for ones that have extra sidewall protection.

 

I give a big thumbs up on Trey's power tank[sm=goodidea.gif]