recommended pressure when airing down tires?

[rrliljedahl]

I own a 2010 Rubicon 4 door with the standard 32 inch BF Goodrich tires. The vehicle weighs about 1000 pounds over the stock weight when loading down for camping with people, extra fuel, water, tents, and food.

My question is how low can I go when airing down before I run the risk of them debeading when driving on sandy beaches or rocky trails?

Thanks.

 

[Mr. Leary]

You can go lower on sand then rocks.

I wouldn't go below 10psi on sand... and 15 is usually a pretty good number. Rocks... keep it at or above 12psi so it doesn't twist off trying to side bite a boulder.

 

[htek]

On my cherokee, I consistently run about 8 psi in the rocks and when snow wheeling. That is with 35x12.50's on an 8" rim - usually loaded fairly heavy for a weekend of camping. I have never de-beaded a wheel, but have burped air (once) in this configuration. And to qualify that, this is doing trails like the Rubicon, Fordyce, etc - not cruising some bumpy forest service road.

You also need to consider the tire width and rim width to determine how low you can safely go. However, based on my experience I suspect you can go down to 10 and be pretty darn safe and pretty much have 0 worry about de-beading. Shoot, if your in a pinch in deep snow or sand I wouldn't hesitate to take it down to 6 if you are careful - or at least I wouldn't on my truck.

That's a pretty long drawn out way of saying my opinion is that you would be fine down to 10psi in just about any terrain. No better way to find out than to go prepared to a "local" wheeling spot and do a few things to see how your truck reacts. If you lose a bead, well then you went too low. Being able to re-seat a bead in the field is a pretty invaluable skill...

-jm

 

[Rexsname]

There was a thread here a while back that described a different way to do things.....

Measure the height of the tire from the ground to the bottem of the wheel. Lets say for the example that its 6"..... deflate the tire until it is 75% of that height or 4 1/2" then take a look at the tire presure. That should get you in the ballpark and it works for a heavily loaded or lightly loaded truck.


REX

 

[john101477]

I generally go down to about 10psi on my toyos on the 4runner. I have gone down as low as 6psi and ran all day with no problems but for piece of mind 10 is fine for a slight bulge and a good grip.

 

[bob91yj]

12-15 PSI generally works for me in the LJ running BFG AT's, 10 psi and it is REALLY loose at even moderate speeds. 12-15 also gives me a little room to go down more if I somehow find myself stuck, and allows decent performance on short pavement sections. I've got OBA (Kilby/York) so it's not a huge concern for me if I screw up and go down too far.

I currently run Interco TSL/SX bias plys and beadlocks on my rock Jeep. I consistently rolled BFG MT 35's off of 15" wheels running 8-10 psi running Hammers Trails (extreme rocks) at Johnson Valley, CA. I'll take the TSL's down to 4-5 PSI in the rocks with the beadlocks.

 

[JCMatthews]

Don't Worry

I spent 10 years as a trail guide for the Easter Jeep Safari in Moab. I ran the '97 Cherokee I used to own (I almost started to cry when I realized how different Easter will be this year). I was nervous at first, and started my tires at 18 psi, then the next year at 15 psi, and so on. I found that I could run my 33x10.5 BFGs on AR 767 steel wheels at 8 psi. Comments were made regularly about my ability to climb obstacles. I would let them know what pressure I was running and that is why. A stiff tire can't grip, and will puncture more easily than a flatter tire. Also, on one run of Gold Bar Rim, I was running as a trail gunner, by myself (Rick Pewe of Petersen's 4Wheel and off road had just gotten out) the stereo was on, the window up, and I was just enjoying my day. I tried a direct line up an obstacle and did not make it, I backed up slightly and readjusted and came right up. Several folks came to see what I had broken, because there had been a loud sound when I first tried the climb. I hadn't heard it because I was in my climate controlled environment. They realized that I had put enough pressure on my front tire to let air out around the bead. I only lost a few pounds, and the tire stayed firmly on the rim. For best results 8 to 10 psi, but if you don't have access to air, 15 psi and you can still drive to air. I hope this was not to long, and that it helps.

 

[thejafe]

For best results 8 to 10 psi, but if you don't have access to air, 15 psi and you can still drive to air. I hope this was not to long, and that it helps.

I will second this . Good advise.

 

[RedRocker]

I run 33 12.50 at around 12 with good all around results. My friends that run 35's usually run around 9. The load rating of the tire can make a difference as the sidewall can be stiffer or softer depending on what you have.

 

[Colorado Jeeper]

I have a 2010 JKU Sport but with the same wheels and tires as you. I run pretty loaded down (wife plus five kids and associated gear), I have found 13psi to work well.

 

[drbandkgb]

My BFG KM2s Ill run down to 18psi Mix of rock and mud

 

[Gooseberry]

I air down to 30psi and it works pretty good. Anything below 25 and it just fells like its going to break the bead.

9K lbs on E rated tires

 

[Sal-XK]

I air down to 30psi and it works pretty good. Anything below 25 and it just fells like its going to break the bead.

9K lbs on E rated tires

Do your tires even flex at 30PSI.

I agree with most the post here but you need to fine tune with your tires and weight combo. I to was unsure when I started airing down and only went down to 22PSI the first time out. But I just kept bumping the air down until I noticed my tires flexing enough to get the job done. For most trails I run down to 15PSI with a 5,000 LBS jeep. But for something extreme I will go lower but 10PSI is the edge of my comfort zone.

 

[JIMBO]

:sombrero: I leave mine at 28 psi, unless it's a real steep shale/rock climb-then about 18psi (stauns set) and lockers--

Now deep snow,--WAY DOWN 6/8psi-doesn't happen too often-

If I have to go X miles on washboard road-at speed, then 18 psi for jeep and 15 psi for trailer-


:costumed-smiley-007:wings: JIMBO

 

[K2ZJ]

I air down to 30psi and it works pretty good. Anything below 25 and it just fells like its going to break the bead.

9K lbs on E rated tires

Do your tires even flex at 30PSI.

I agree with most the post here but you need to fine tune with your tires and weight combo.

If he is driving this: 2000 7.3 E350 PSD smb, I would guess so.

I also agree you need to go out and try different pressures.