Ok, here's the real deal. If your floating down the road like a Cadillac then you don't have enough air. If your bouncing all over the place then you have too much. If people point as they drive by, you've lost a tire. If cars won't pass you, your about to lose a tire.

Come on people, you have to feel the road and look for the visual clues on tires and pressure....GEEZUS

 

Or you could just use an air guage and check the pressure. :P

 

The most important visual clue would be seeing the pressure reading on a tire gauge. :lol:

 

I wold try and contact the Firestone technical support department (IF THERE IS ONE AND i CAN GET IN TOUCH WITH THEM) but my guess is that they would say to keep the stated pressure on the side of the tire.
and somehow I agree: "The company that produced the tire should know best what pressure it should be inflated to"
Regards

 

I kid you not- my steers are stamped 130 psi cold, we have XOnes which are stamped 120 psi cold, and our trailer is tri-axle single tires stamped 130 psi cold for single (vs duals). Just try finding shops to put air in if you get low or have a leak... the truck stops don't even trust their own mechanics with anything more than 120 most of the time. And if I check my tires in the morning and they're at 105ish, by the time I drive up to the fuel island they're already at 115 or so. It stinks.

If you buy XOnes from most places they can't even fill them to the tire manufacturers recommended psi. That's a joke.

 

I ran a set of Michelin XDA-HT 11R24.5's at 85 psi running Canadian weights of 18,700 lbs per axle tandem dual.
See http://www.michelintruck.com/micheli...o?tread=XDA-HT

If you look at the manufacturers website and look up the load chart for your tires you'll see exactly how low you can go and still be o.k. The rating on the sidewall of the tire is the absolute maximum the tire can withstand. If you put in more pressure than what your truck maufacturer recommends then the tire will skip down the road and cup out early.