The PSI stamped on the tire is the max pressure for that tire. There's no way a tire manufacturer can know exactly what vehicle their tire is going to mounted on, so they leave it up to the individual auto makers to determine what the best pressure to run is.

Unless the bed is loaded down or towing...there's no reason to run more than 35-40 psi.

 

Apparently I'm not doing a good job explaining...

http://www.tirerack.com/tires/tirete...e.jsp?techid=1

Good reading in there, if tires are your concern..

Vehicles are designed around available tires as much as the opposite is true.. the stamped tire pressure on the tire is what that maker wants.. the door jam is what the other maker wants.. obviously load plays a role.. the higher pressures help a tire designed to hold it maintain their shape, and keep them cooler..

P rated tires list maximum pressure.. true.. the tire in question is not p rated.. it is a light truck tire.. they should have a range printed.. my duragrapplers I just put on state a range, for instance.. they say 45-80psi.. logic would dictate that weight will determine psi, but the object is to keep them in expected shape..

Running them above max will cause premature wear.. so will running them low.. inside that range will keep them in shape, and not cause wear unless there is deviation with the other three..

P rated tires have max printed, I say again.. the tire in question is not a p tire..

 

I've driven on and checked the pressure of many, many tires. The rig I'm driving right now has 26 tires...the air seeder has over 70. I have never inflated a tire to what the max pressure reads on the sidewall, besides for seating a bead.

Tire pressure is not rocket surgery...look at the tire, if its a balloon, you've got too much air in it, if its sunken in the middle, not enough. Check it often, and watch the wear.

 

Yup.. I concede to the man with 26 tires..

The ir temp gun is a nice trick, though.. it flat out won't lie..

 

I agree.

 

Just for the record, the DuraTracs in "D" rating do not have a "range" printed on them. Only "max cold inflation 65 psi. We've got them i two different sizes on two different vehicles, and both say the same thing.

 

You need to run these tires on the high side. Closer to the max PSI BUT NOT OVER.

It's well documented that Duratracs have WEAK sidewalls and as such, are much better suited to the Jeep crowd (where they are very popular). There are MANY cases of failed sidewalls when used on full size (heavier) trucks. Keep the sidewall fairly rigid to help minimize the risk of a sidewall failure. Keep tow/haul weights on the lighter side as well...

 

Guys,

I'm new here so go easy! Looks like a little fightin' is going on and it's not my intent to fan the flames, but here goes:

I have a 07 Megacab 1500 which is technically a 2500 but I digress... At max inflation pressure (60 front and 70 rear) the truck makes you want to puke your stomach out. I did some research and found the Michelin specs for my 265/70-17 tires along with the load table. Since my truck is 6400 lb with 57/43, front/rear weight distribution, this gives me 3648/2752lb for the overall weight per axle. Using Michelin's table I can run the front at 35psi (3780lb) and the rear at an astonishing 25psi, but I keep them at 35psi. Even at max load of 8500 lb the max pressure I need to run is at 45psi which will support 4510 lb per axle.

That's all quite a difference than the 60/70psi for front and back that's published on the cab card. Once I've run them a while, I'll check the tread wear pattern to make sure they're wearing flat and adjust from there, but it's a much better point to start than to simply go to the max pressure AND it's a good ride for a 3/4 ton.

I can send a link out for the spec file from Michelin if anyone would like, but I just used google to find it.

-Greg

 

What I use is the OEM spec PSI chart, and add 5-10 PSI to it.

On my Ram, I am running 285s with 45 PSI in the front, and 40 in the rear. Doesn't seem like much of a change, but it actually helps the ride out.
I've considered going 50-45, but haven't felt like spending the quarters to do it (damn pump is $.75 to operate ).

 

I'm running cooper zeon ltz's in 305/55/20 (E rated) at 45psi at all four corners. Had them there for over a year now, and they seem happy. I good tread wear and handling.