Airing Down for Off Road

[Johnny O]

Ok. You guys successfully taught me how to set tire pressure for pavement driving with the chalk method.

Now I’m curious about airing down for off roading. In all the miles I’ve done in Bert off road, I’ve never done it. Heck, didn’t even really think about it.

In just two weeks, Bert and I are gonna hit the trails at the famous Tuttle Creek ORV park. The driving instructor for the group I’m in and trails were running sweats Bert will do anything a wrangler can do and then some if I air down.

I’m running stock size Toyo AT3s.

 

[lfhoward]

What kind of terrain will you be on at the ORV park? Airing down helps with increasing floatation on sand, and also makes it less likely you’ll get a puncture on sharp rocks. It also increases the contact patch with the ground, increasing traction. Maybe 20 lbs is a good place to start. For sand, maybe 15 lbs. I wouldn’t go any lower because the tire could come off the bead. I’ll let others with more experience chime in as well once we hear what the terrain is like.

 

[Johnny O]

What kind of terrain will you be on at the ORV park? Airing down helps with increasing floatation on sand, and also makes it less likely you’ll get a puncture on sharp rocks. It also increases the contact patch with the ground, increasing traction. Maybe 20 lbs is a good place to start. For sand, maybe 15 lbs. I wouldn’t go any lower because the tire could come off the bead. I’ll let others with more experience chime in as well once we hear what the terrain is like.

From what I know of the place, it’s dirt and shelf rock. Quite a bit different from the soft Sandhills and desert hard pan I’m used to.

 

[Ruby]

I wouldn't go lower than 20 ish (big ish) (everyone's got different tires and vehicle weight) for dirt and rock. (Unless your running beadlock rims then do what you'd like)
Reasoning;
Airing down tires contrary to public belief isn't the magic answer to traction. It's main purpose is to widen surface area on sand or mold around rock surfaces to lessen impact and use the full contact patch on non flat surfaces. Rule of thumb might be lowest to highest silt/powder sand, beach sand, rock, gravel, pavement.
When running rocky hills however, you have to balance those small gains in traction with how hard your vehicle is going to hit stone. The lower the air pressure, the more likely you are to bend your rim out of shape and cause a leak. So about 20 is where I like that balance for my vehicle.

In summary there's nothing equivalent to the "chalk method" for Airing down tires offroad simply due to the endless variables in your car and the terrain. Anyone who claims otherwise is selling snake oil. Experience is the best teacher and when you practice enough you'll find the numbers you like best for your car.

If the goal is traction, talk with couse instructors about how to correctly take lines, weight distributions, and steering techniques that are much more effective in picking up traction.

 

[Yetiboy01]

With 245/75/16 tyres I run 24 psi touring on stoney roads to stop impact fractures & **** outs caused by the tyre not being able to conform to the sharp stones when driving over them, on the beach I'll start at 15 psi & if needed will drop pressures as required, drove across the Simpson Desert at 10-12 psi, no tyres came off the rims on over 1100 dunes, on the beach I will drop them as low as needed to get through a particularly soft spot then air up once through, on my CJ8 37's bead locked off road usually run between 6 & 8, anything more & I dont get the traction I need

 

[tommudd]

Have to remember the extra weight you are carrying as well
What 20 lbs does for one with a light load , may not work for your load etc
just keep that in mind as well