What's the lowest comfortable tire pressure on factory Mojave/Rubicon AT/MT wheels and tires

[Volt0]

When I bought my JTM, the salesman was saying that I could lower all the way to 7psi on the factory 33" WildPeak A/T tires ( non beadlock ) without the risk of unseating the tire. I've gone down to 20psi for some casual forestry trail riding ( nothing too serious ), but the backend felt a little squishy side-to-side. It did great in terms of traction and comfort, and honestly those C rated tires didn't bulge out as much as maybe they could. What's the lowest you would comfortably go, and in what terrain ( forestry, rocks, sand, snow, .. )???

Note: I don't have a lot of sand around where I live, but would expect a casual beach driver to be able to go really low, and maybe someone blasting through whoops might want a little more ( and/or bigger tires ).

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[mx5red]

Surely depends on use, as you allude to. I’d try pretty low on sand, but would be afraid to go that low driving faster over bumps/rocks/logs.
I used staun deflators to go to 18 or a little lower and seems fine off-road.

I believe a video of casey250 on YouTube stated he wouldn’t go below 12 with his teraflex nomads, which have ribs to help keep the bead from unseating (and another guy lost a bead, I can’t recall how low he said).
I think I’d be afraid to go lower without beadlocks, but maybe you could get away with it on the beach.

 

[Brojave22]

beach I go to 20 psi never had an issue, I go a few times per week for the past 16 years, all different jeeps, this one no different

 

[BearFootSam]

I’d agree it is very use dependent. 7psi sounds really low but you might pull that off at lower speeds on soft sugar sand. Sand is a relatively homogeneous surface that conforms to your tires and distributes the load evenly. Conversely on a trail with rocks, wood, etc, you have a greater risk of popping bead.

Consider, there isn’t a set tire pressure that works across the board. Your driving style, vehicle weight and surface will dictate how low you need to go. For trail riding I’d start at 20-22 and see how it goes. You may not even need to drop pressure for traction but I normally do to lower the risk of punctures. Running street pressure of 36-37psi on sharp rocks is really tough on tires and will chew up your tread. Too low and you lose ground clearance unnecessarily and create more turning resistance.

The Falkens have good wrap around lugs that will keep your sidewalls fairly protected when Aires down.

 

[joeym7]

No need to lower pressure on "fire trails" around here anyway. The MO will go through these quite easy which usually include patches of deeper sand, and some significant deep puddles with muddy bottoms. But I will caveat, they have some, but not a material amount of rocky surfaces (mostly dirt, sand, significant puddles, and mud). I usually do this in 4wd High and with Off Road + on. OR+ will blast through anything it seems and it is just more fun driving MO with it on even when it is a dirt road that doesn't actually need the extra "boost".

On the Beach I lower the pressure to 18 psi. Which is about 50% lower than the 37# factory speck. I personally think rather than picking an absolute number, the % change is a better way to think about it. With 18 psi it does just fine, and if you find you are having a hard time, again, Off Road Plus is your friend, it will blast through just about anything...And this is always in 4WD-High, although on my first beach trip when I first got MO I was cautioned to use 4WD LOW by the locals, so I did try it at first, but quickly found in reality it is not needed...Maybe 4WD-Low might help if in the rare occasion one does get stuck, but it hasn't happen to me up to this point so I couldn't say.

Overall, unless going beaching, as I don't live near a desert, I like to keep my tires around 34-35 PSI (cold), just a tad off the Factory spec., 8% to 5%, which is (not) a material amount, but I find it rides just a little nicer on pavement and works just fine on anything around here off road except the beach (where I go to 18PSI as mentioned above).

 

[Rahkmalla]

No need to lower pressure on "fire trails" around here anyway.

Finally got my arb twin compressor installed so yesterday was my first time getting to air down on my local light trails, which are little more than fire roads.

You are correct that airing down for light trails is completely unnecessary; I ran them all the time at normal psi. But man, the ride is so much better at 18 psi with a sway bar disconnect than it was at full pressure with a sway bar disconnect, which was again much better than full pressure with zero disconnect.

The types of trails I run haven't changed, but my comfort level has dramatically.

 

[dcmdon]

beach I go to 20 psi never had an issue, I go a few times per week for the past 16 years, all different jeeps, this one no different

A few times per week for 16 years!! Wow. How many compressors do you go through per year. Ha.

Seriously, what kind of compressor do you use? I would consider you to be an expert on this by now?

Do you air up all the way when going back on road or do you cheat a bit to make it quicker, by going to something like only 30 psi??

 

[Brojave22]

A few times per week for 16 years!! Wow. How many compressors do you go through per year. Ha.

Seriously, what kind of compressor do you use? I would consider you to be an expert on this by now?

Do you air up all the way when going back on road or do you cheat a bit to make it quicker, by going to something like only 30 psi??

The beaches here provide air compressors at all the outer beaches, probably 5 or 6 stations, so never really needed one. I use the tire deflators from xbull so all 4 tires go down to 20 psi at the same time and go back up to 38psi when going home. The compressors here have like 300psi so they are very fast to inflate all 4 tires when leaving, but the compressor I do have is an arb, only used it a few times

 

[Volt0]

Overall, unless going beaching, as I don't live near a desert, I like to keep my tires around 34-35 PSI (cold), just a tad off the Factory spec., 8% to 5%, which is (not) a material amount, but I find it rides just a little nicer on pavement and works just fine on anything around here off road except the beach (where I go to 18PSI as mentioned above).

I’ve done the same thing occasionally, and thought about having the front JTM shocks rebuilt, to be adjustable. My wife’s JTHA is our preferred ride for longer trips, and the JTM is our preferred for off-road things. I thought maybe if the front fox shocks were adjustable, we could use a highway setting and then flip over to an off-road setting, without killing mpgs by running a little under inflated.

 

[Wheelin98TJ]

8-10 for sand or snow. 10-12 for trails.

 

[Volt0]

8-10 for sand or snow. 10-12 for trails.

Interesting, and to confirm, you’ve done this on the falcon factory 33’s? I’m assuming that you kept your speed low as well?

 

[Gvsukids]

Interesting, and to confirm, you’ve done this on the falcon factory 33’s? I’m assuming that you kept your speed low as well?

I've lowered to 12psi on the sand with the factory Wildpeak tires. I've also gone down to 20 on Drummond Island, which is rocky.

 

[FitfulGoat]

I personally wouldn’t go below 10psi on non beadlock wheels without tools and a compressor handy.

That being said 15-18psi was a good spot for the stock tires when I had them on. No sand really so can’t comment there but on rocky trails in NM, AZ, and CO they did good.

 

[Wheelin98TJ]

Interesting, and to confirm, you’ve done this on the falcon factory 33’s? I’m assuming that you kept your speed low as well?

I haven’t on those specific tires.

My response is based on my experience with several different tires on several different wheel widths on several different vehicles.

 

[Jefe1018]

15-20psi seems to the sweet spot between comfort and danger of losing the tire for me.

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