Canadian Hummer Club Forums

35x18.5 Duratracs on 18" rims what PSi should I run them at on the hwy? should I air them down for mild offroad? I've googled cant find anything> <img src='http://www.canadianhummerclub.com/forum ... #>/c-n.gif' class='bbc_emoticon' alt=':coffeenose:' />

Should say right on the tire, no?

[quote name='Monkey39' timestamp='1328773820' post='34927']

35x18.5 Duratracs on 18" rims what PSi should I run them at on the hwy? should I air them down for mild offroad? I've googled cant find anything> <img src='http://www.canadianhummerclub.com/forum ... #>/c-n.gif' class='bbc_emoticon' alt=':coffeenose:' />

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I would run what your PLAY CARD SAYS ON THE DRIVERS DOOR ! If mild off road , you don't really need to air down . If you are doing mainly rock and sand yes . It depends on the terrain course you will be wheeling on . You could be even doing airing up and down . A Lot of guys will air down between 15,18,20 PSI from normal ( play card ) settings !

[quote name='johnnyspikesH3' timestamp='1328809124' post='34939']

I would run what your PLAY CARD SAYS ON THE DRIVERS DOOR ! If mild off road , you don't really need to air down . If you are doing mainly rock and sand yes . It depends on the terrain course you will be wheeling on . You could be even doing airing up and down . A Lot of guys will air down between 15,18,20 PSI from normal ( play card ) settings !

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Take also into consideration the PSI written on the side wall of the tire, especially of they are not the originals size.

The pressure in the door mean nothing...especially if you have a larger that stock tire.



Every tire and every truck has a slightly different way that it reacts to the road surface, so no sticker in the door can match that. The best way to set tire pressures is to make a chalk line across the tire and then drive in a straight line for 300ft. Check the wear of the chalk line. If the center only is worn, the pressure is too high. If only the edges are worn then the pressure is too low. If the line is evenly worn off, you have now found your ideal pressure. There is an article in the April 2012 Fourwheeler magazine that shows exactly how to do this...it just isn't posted on the website yet!



For offroad, ideally you should always air down, it protects you tires and your Hummer. I must say that even I don't always air down, but we really should. When you do air down 18psi is the lowest you should go without beadlocks. I normally air mine down to 10psi but can go to 0psi, since I do have beadlocks on my H2. Low pressures offroad really help you get grip and tread lightly!



Hope this helps!



Kev

For all you H1's out there ..make sure time to time you take a presure gauge to check your tire psi....the gauge in our H1's are off some times

my 2 cents <img src='http://www.canadianhummerclub.com/forum ... #>/c-n.gif' class='bbc_emoticon' alt=':coffeenose:' />

I've been airing down the H2 to 18 psi when wheeling. Seeing some good flex from the tire when you need it but nothing scary like I'm about to ride the rim. Noticeably better traction!

[quote name='Archngel' timestamp='1328827989' post='34941']

Take also into consideration the PSI written on the side wall of the tire, especially of they are not the originals size.

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The PSI on the side of the tire is only the maximum safe pressure the tire is rated for, nothing to do with operating pressure. That tire could be used on a variety of vehicles with a wide range of weight.



As mentioned, best place to start for pressure is the door sill. That will be the manufacturers recommended pressure for stock tires. As Kevin mentioned, to fine tune a tire you can use either chalk or shoe polish to see how much it is rolling over in corners and adjust the pressure up or down based on that.

dealers are known to do psi +5 when filling tires in shop