lowest tire pressure?

This is a very broad question, depends ofyour wheels, tires and terrain. I have run 5 psi on TJ's without issues on steel black wheels without issues with MTR's and BFG's and Swampers. Carry a can of starter fluid and a match just in case.

For any wet condition, mud or snow, at least 10 psi to keep the bead from spinning. If you have 16.5 wheels (not the case likely), they do not have a inner retention bead ring, and dropping below 10 psi will make the tire spin or pop...ask me how I know lol: Opening the door to see your front tire next to you sucks:

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swampdog said:
Dude, you need to take all of this with a grain of salt. There are so many variables here in people's responses the play a role in ability to hold a bead at low pressure...sidewall height, rim width vs tire width, wheeling conditions, etc. To just drop air pressure arbitrarily based on forum responses with tons of variables is just silly.

Drop the air pressure to 15 ( a good starting point for most all combinations) and wheel it. Then, continue dropping a pound as the day goes on until you find either a) the sweet spot for your setup, or b) the point where you lose a bead. This is the only way as YOUR rig is not the same as everyone else that is responding.
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believe me , I take everything on the interweb with salt. just gives me a good basis to start with . I have never aired down until I went to Moab.( and I didn't drop much pressure) I was worried about the tire coming off with little air and good traction
 
Airing down helps a ton. I know your question is more related to tire not coming off the bead, but thought you guys might find this cool too. It was in JP magazine a few months back. Showing how low tire pressure affects the surface area of the tread. I thought this was a really cool visual test.

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WJCO said:
Airing down helps a ton. I know your question is more related to tire not coming off the bead, but thought you guys might find this cool too. It was in JP magazine a few months back. Showing how low tire pressure affects the surface area of the tread. I thought this was a really cool visual test.

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This is really interesting. My takeaway is that you don't gain much going from 20-15psi except more sidewall bulge that could get snagged on a rock and rip. So stay at 20 unless you're ready to go all the way down to 10 (or less). Am I interpreting that correctly?
 
GraniteCrystal said:
This is really interesting. My takeaway is that you don't gain much going from 20-15psi except more sidewall bulge that could get snagged on a rock and rip. So stay at 20 unless you're ready to go all the way down to 10 (or less). Am I interpreting that correctly?
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That's how I see it, but as your sidewall flexes more, I imagine it does give you more 'wrapping' or flexibility on uneven rock surfaces.
 
I've been experimenting with airing down a lot over the last year, and I can tell you right now, when I'm playing in a very rocky area, I can tell the difference in traction and ride smoothness between 20 PSI and 14 PSI, which is what I currently run my 35's at. Although when you are on a flat surface the sidewall bulge is more noticeable, when you are crawling on rocks, the tires sort of engulf the rocks to increase traction. I think the flat surface bulge is the result of the tire having nothing to grab onto but a flat surface, so it just bulges out the sides. Put a tennis ball size rock or larger under the tire, and the sidewall straightens out a bit while the tread engulfs the rock. I am going to try 13 PSI and possibly even 12 PSI the next time I'm wheeling with someone that knows how to pop a bead back on while on the trail lol.
 
TheFunSmith said:
I've been experimenting with airing down a lot over the last year, and I can tell you right now, when I'm playing in a very rocky area, I can tell the difference in traction and ride smoothness between 20 PSI and 14 PSI, which is what I currently run my 35's at. Although when you are on a flat surface the sidewall bulge is more noticeable, when you are crawling on rocks, the tires sort of engulf the rocks to increase traction. I think the flat surface bulge is the result of the tire having nothing to grab onto but a flat surface, so it just bulges out the sides. Put a tennis ball size rock or larger under the tire, and the sidewall straightens out a bit while the tread engulfs the rock. I am going to try 13 PSI and possibly even 12 PSI the next time I'm wheeling with someone that knows how to pop a bead back on while on the trail lol.
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I ran 12psi on my stock rubi wheels/tires every time I wheeled. I never had a problem. But I was also stock, so ground clearance was a limiting factor. How wide are your tires? Rims?
 
Up here In Canada. My jku has 35 mtz I run 10-15psi in the trails and snow winter runs I go as low as 6 psi never had a problems yet ;p
 
What are you guys running on the street with 35's and stock wheels? I run the all over the place from 20psi to 38psi, I just want to see what the happy spot is?
 
Not trying to high jack the thread but just ordered my wheels and tires today. MB 11 wheels 17x9 with Nitto terra 295/70x17s. Guy Said 43psi should be used on the highway. I run 30psi for long trips 26psi normally. 20 if I think I'm going off road. 16 if I am which is more compared to most. Do the chalk test and see where you are comfortable. That's the advice I got from WAL and it worked for me. Have fun wheeling!
 
WJCO said:
What was this guy smoking and where can I buy it?
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Haha I know right. It was discount tire I'm sure he was reading the factory spec sheet. Not to knock them cause those guys are great. Called me after my order to let me know the wheels were on back order. Offered a deal on a different set since I have to wait. Gonna wait for what I want though so I have to give them a thumbs up!
 
DWiggles said:
I ran 12psi on my stock rubi wheels/tires every time I wheeled. I never had a problem. But I was also stock, so ground clearance was a limiting factor. How wide are your tires? Rims?
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Im running 315/75/r16 Nitto Trail Grapplers. I'm super happy with them! I'm excited to keep airig down lower, just to see how much better the traction can possibly get.
 
DaBank said:
What are you guys running on the street with 35's and stock wheels? I run the all over the place from 20psi to 38psi, I just want to see what the happy spot is?
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I'm running my 315/75/r16's at 33 PSI and they ride comfortably and I'm getting good mileage too. Just chalk test and see where you should be with your tires.

BdugJK said:
Haha I know right. It was discount tire I'm sure he was reading the factory spec sheet. Not to knock them cause those guys are great. Called me after my order to let me know the wheels were on back order. Offered a deal on a different set since I have to wait. Gonna wait for what I want though so I have to give them a thumbs up!
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My Discount Tire has always done right by me. They only filled my Trail Grapplers up to 35 PSI, without me even asking them to. After the chalk test, assuming I did it right, I only needed to drop 2 PSI from what they had originally filled them to. Its nuts to think they would fill up to 43 PSI, those tires must have felt like they were filled with cement!
 
TheFunSmith said:
I'm running my 315/75/r16's at 33 PSI and they ride comfortably and I'm getting good mileage too. Just chalk test and see where you should be with your tires.



My Discount Tire has always done right by me. They only filled my Trail Grapplers up to 35 PSI, without me even asking them to. After the chalk test, assuming I did it right, I only needed to drop 2 PSI from what they had originally filled them to. Its nuts to think they would fill up to 43 PSI, those tires must have felt like they were filled with cement!
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Not sure what they feel like. Wheels are on back order until the end of May. :banghead:
 
swampdog said:
Dude, you need to take all of this with a grain of salt. There are so many variables here in people's responses the play a role in ability to hold a bead at low pressure...sidewall height, rim width vs tire width, wheeling conditions, etc. To just drop air pressure arbitrarily based on forum responses with tons of variables is just silly.

Drop the air pressure to 15 ( a good starting point for most all combinations) and wheel it. Then, continue dropping a pound as the day goes on until you find either a) the sweet spot for your setup, or b) the point where you lose a bead. This is the only way as YOUR rig is not the same as everyone else that is responding.
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I wanted to know this too. I agree with you. I have 16 inch rims and I am currently running 35/75/16 Korean brand tires and they got real giggly at 13. I have done 15 3 or 4 times and seemed ok but I think I hit the wall at 13.... Do a lot of experimenting and work your self to lower pressures. If you go somewhere new you just need them low enough to do the job.

My .01 + .01 cents worth.
 
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