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General Forums => The Mess Hall => Topic started by: slazyks on May 27, 2012, 06:34:13 PM

Title: PSI help
Post by: slazyks on May 27, 2012, 06:34:13 PM
I've got 31/10.5/15 BFG MT AT2 on my tj.  The tire people inflated them to 40 psi.  Today while running Cleghorn I was told I never should have my tires that high and that 28 was good for street.  So I googled it and of course I got a trillion different answers.  Some say 26 some 35 some 32 etc.......  I lowered the pressure down to 35psi (while tire was warm).  BTW the sidewall say's 2270 max load single at 50psi.

What do you all think? 
Title: Re: PSI help
Post by: sharpxmen on May 27, 2012, 06:36:46 PM
between 28 to 32 should be fine, i run 32psi with 33x12.5x15, imo 40 is really high,
Title: Re: PSI help
Post by: aw12345 on May 27, 2012, 07:28:50 PM
28 to 30 is fine, you can to the chalk line or what ever it's called and see where the tires contact the ground
Title: Re: PSI help
Post by: grumpygy on May 27, 2012, 09:30:56 PM
The Higher pressure is for use on a heavier vehical like a truck.  The Max numbers would be for a loaded truck.

  Our jeeps are really light an d would beat us to death at the Higher Numbers. 
Title: Re: PSI help
Post by: slazyks on May 28, 2012, 07:47:58 AM
I'm going to do the chalk test this morning since my wife chose me to be the one to go get a good spot at the park bright and early.  I'm going to drop them to 32psi and check it.  Thanks for the input.

HAPPY MEMORIAL DAY!!!!
Title: Re: PSI help
Post by: Jeffy on May 28, 2012, 11:42:04 AM
It really depends on the tires contact patch.  This will depend on the tire width, wheel width as well as vehicle weight. Wider tires on a narrower wheel will cause the tire to wear like it's over-inflated unless you lower the PSI.  The downside is lower pressure means the tire will ride softer and generate more heat which means wear.

When I was running 35x12.5R15's on 15x8.5's I had to run around 25-27psi to get a even contact patch.  For my 33x10.5R15's on 15x7's I run 35-40psi.  So whoever told you you shouldn't run your tires over 28psi doesn't really know what they're taking about.  It's not a one-size fits all sort of thing.