Tire Pressure

BTW, we have two new tri-axles chassis with a PSI inflation system, they came from the factory set to 120. The boss now has it adjust to run all 12 tires at 100 psi. He installed a little port by the adjuster, we can hit it with our tire gauge if we need to know what it's set at. Anytime a tire is more than 5 lbs low, a light comes on to indicate the system is active and inflating the tires. In two years, no blowouts. Even our regular non-inflator tri-axles, we run 100 psi in all tires with no issues, and these are constantly running 45K loads.

 

Like I said, if they don't want to give me (or an officer) a range on the tire, for a so-called recommended "normal", I'm going with maximum inflation, because inspectors would go by the sidewall number, and if a tire blows, causes damage or injury to someone else, when all my other tires are "low" according to that number, they will probably say it was preventable or cite me on routine inspection, and I don't want to get into this discussion about tables when they don't go by that, besides I'm not often by a scale where I could measure exactly how much weight is on what axle for local stops (not that I'm over, but may be close to max), so max pressure makes the most sense to me, and has the greatest margin of error (as the max load stated across my tires isn't that much more than axle regs, like yours seem to be).

Here's an article describing the situation:
Under-inflated Tires Are No Longer Just an Efficiency Issue: They Can Affect Your Safety Profile

Moral of the story: "We'll be looking at the maximum cold inflation pressure stamped on the tire"...

"Department of Transportation's own numbers suggest under-inflated tires could be a significant enforcement concern for the industry (only 44 percent of all truck tires are within 5 psi of their target inflation, FMCSA has found)"... guess what, their "target" is your sidewall.

"Most law enforcement personnel use simple tire gauges, which are notoriously inaccurate"... guess what, if you're close to underinflation, their gauge won't help in the matter.

"Tire violations are very serious (and always have been), because they are such a high safety risk"...

 

Check tire pressures cold . Use an accurate tire gauge . 70 degrees Fahrenheit temperature is the reference temperature . For every 10 degrees above 70 degrees add an additional psi to your target air pressure
80 degrees +1 psi , 90 degrees +2 psi , 100 degrees +3 . For every 10 degrees below 70 degrees subtract psi from your target air pressure 60 degrees -1 psi , 50 degrees -2 psi , 40 degrees -3 psi . Sun shining on tires will throw your tire pressure readings off .

 

Just not gonna quit are you. Love the selective "sound bite" quote. Let me post the COMPLETE sentence.

"We'll be looking at the maximum cold inflation pressure stamped on the tire, and determining a tire to be run flat if it's at 50 percent or less of that rating."

50% of 110 is 55, 50% of 120 is 60. No place in the Tire and Rim Assoc. Load/Inflation tables or any of the manufacturers tables can I find a recommended inflation of 50 or even 60 psi.

Speaking of those tables you refer to with scorn....

Quoted from your holy grail article of course....
If you're keeping up with the math, CVSA says a tire is flat at just 10 psi less than the Tire and Rim Association says is an acceptable inflation pressure for a given load

Well whataya know, CVSA acknowledges and refers to the exact tables you scorn. Hmmm

 

Blow me, if you want to turn this into a soap opera, and I'm talking about tires, so don't take it the wrong way.

 

I will stick with listening to the people who have the most knowledge, the tire designer and maker.

Also I take no pleasure in the extra rough ride from an over inflated tire on our poorly maintained highways.

It does definitely make a difference in the ride as well as the longevity of the tire. Irregular wear can be caused by over inflation. At least that's what the folks at the Technology and Maintenance Council say.

 

Maybe there's too much air in your seat, or do I have that backwards too? Now it's overinflated. Figures.

 

I saw the comment about not using the sidewall numbers on the www.michelinman.com location. I think they're the ones who put the lines and crosshatching on dipsticks.

 

Maybe so. I guess there aren't any tire guys who know what their experience and knowledge mean to truck owners? I don't believe it, I think there are quite a few good, knowledgeable tire professionals in our truck service world. Not to say there aren't a lot of pretenders as well. I guess it's up to us to know enough to tell the difference? There I go, back on that goldang learning curve again.

 

Yer meaning to tell me y'all do more than just kick your tires for a pre trip.. ain't nobody got time for that