Tire Pressure?

How do you decide tire pressure to run?

On the street? On the trail? What do you mean?

I run 3-4 psi in the snow, 8-10 in sloppy conditions, and 10-12 if the trails are dry. 25-28 psi on the street.

-----Matt-----

Too many variables.

Street? Trail? Trail conditions? Tire make? Size of tire?

Stock size tire? use the pressure indicated on the sticker on the driver door. Oversized tires, start with the factory pressure less 10%. Watch the wear patterns. Then adjust the pressure as needed. My 31's are 6 ply tires, I run 28 front and 25 rear.

chalk the tread on one front and one rear and drive it till the wear is even across the tread..
for 35x12.5x15 bfg muds on 8" rims optimal wear is at 26psi fron and 23 rear on my rig

on the trail i drop it down around 8psi all 4

karstic said:

Tire make? Size of tire?

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Good points.

-----Matt-----

Geezzzz, 3-4 in snow, 8-10-12 psi in slop, I didn't know you could run tire pressures that low!

I run 26 to 28, measured when the tire is at ambient temp, usually 26 front, 28 rear. 26 front steers better on the freeways. I have 235R75-15s.

IXNAYXJ said:

On the street? On the trail? What do you mean?

I run 3-4 psi in the snow, 8-10 in sloppy conditions, and 10-12 if the trails are dry. 25-28 psi on the street.

-----Matt-----

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Well, on the street, you should load it up like you normally do for just puttin' around town. then, draw a line on your across the tread of your tire with a piece of chalk. drive for a little bit, and check the tire again, examining where the chalk rubs off most. if it's mostly in the centre, let some air out, if it's mostly on the sides, add some air. If it wears off evenly across the tread, make a note of the pressure you are running, and repeat the test. If it wears evenly through repeated testsc, congratulations; you just found your best pressure!

For other stuff, it REALLY depends. Things like how much you are carrying, load distribution, road/trail/whatever surface, tire size, amount of sidewall flex and even how old your tires and wheel are affect trail pressure. probably the best thing to do is to go on a run with other people who have run the trail before, and ask them. Once you know the pressure they run at, add a couple p.s.i. and run that. If it doesn't work, try letting some more out and try again.

Since there is such a huge range of things that affect a good trail pressure, it's mostly just trial and error. Just make damn sure someone has a reliable compressor or full air tanks. You really don't want to have to drive to the nearest gas station on 8 p.s.i.

Ask me how I know...

Ecomike said:

Geezzzz, 3-4 in snow, 8-10-12 psi in slop, I didn't know you could run tire pressures that low!

I run 26 to 28, measured when the tire is at ambient temp, usually 26 front, 28 rear. 26 front steers better on the freeways. I have 235R75-15s.

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Tire pressure is the cheapest most effective mod you can make to improve offroad traction. You're not running 28 psi on the trail, are you?

-----Matt-----

The tires are 245/75/16 good year mtrs

i member when i had my 1st truck when I was a teen, i ran 60 PSI on my bridgestone duelers 31", I took it into a shop and the guys gave me a free tire gauge and a book on tire pressure.

get beadlocks inner and outer and run no tire pressure.

Check this out.

http://californiajeeper.com/tire-presures.htm

lowrange2 said:

get beadlocks inner and outer and run no tire pressure.

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You always amaze me with your insight...

Robert

Robert 771 said:

You always amaze me with your insight...

Robert

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LMAO Just throwin out ideas... lol

Yes, but the only trails I run are the Houston highways and once in a blue moon, the Galveston beaches, LOL.

IXNAYXJ said:

Tire pressure is the cheapest most effective mod you can make to improve offroad traction. You're not running 28 psi on the trail, are you?

-----Matt-----

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lazyxj said:

Check this out.

http://californiajeeper.com/tire-presures.htm

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Nice link.. According to that I should be running 14-17 psi on the road. I'll lower mine to 20 and see how it goes...

NewOld96xj said:

Nice link.. According to that I should be running 14-17 psi on the road. I'll lower mine to 20 and see how it goes...

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How do you figure that?

An XJ weighs roughly 4000#, the minimum off-road pressure given is 14 psi, for every 10mph over 20mph you add 3psi. So at highway speeds (60-70mph) you should be somewhere between 26-29 psi.

On the street I run 15 in the rear and 12 in the front.

Off road I run 4psi at all 4. In the snow I run them stupid low.

This is 35 maxxis creepy crawlers on beadlocks.

Before the beadlocks and my BFG fiasco I ran 8 on the trail and ~30 on the road.