Tire Pressures

I am curious as to why you have 275/70r 22.5 on that truck anyways? That tire will turn faster and create more heat and also wear faster. With no headrack there to me is no reason to have the smaller tires on it. I have seen a many of those tires go boom! Yes it was on stinger rigs but still.

 

http://www.bridgestonetrucktires.com/us_eng/truck_radials/index_2.asp

I checked the link I posted above and it doesn't go to the page for the tire. So this link does work. Look up the tire from here and it shows you max weight and tire PSI. Doesn't show different weights and tire PSI's, but I would assume considering they're steer tires...they're always gonna carry close to the same amount of weight on them.

 

The tires should be inflated to the recommended psi, but on your truck, I would say 100 is plenty as the steering axle doesn't carry 13000lbs. Tires are basically just a contanier for air, and the proper air pressure will help them last longer. Some recommend higher pressures to decrease rolling resistance, the trick is to watch how they wear. You might try rolling the steer tires over a small layer of sand and see how much of a footprint the tire makes.

 

sxdime makes a good point. If it's a company truck, maybe they're just used to ordering that size of a steer tire. Is your whole fleet like that ? Or do you have stingers and/or tractors with head racks ?

 

yeah, like the tire manufacturer or the vehicle manufacturer know what the other recommend.

http://www.time.com/time/business/article/0,8599,128198,00.html

or did people forget about that little fiasco?



ETA:

The best way I have found to properly inflate a tire for the correct pressure/load...

Chalk test.


draw a line with a paint stick or chalk across the face of the tire.

Drive about 100 feet.

Look at your mark.

If the outside is gone, you are under-inflated.

If the middle is gone, you are over-inflated

If the mark is totally gone, you are properly inflated.

 

As an owner operator I would follow the data plate from the truck manufacturer. After all they are familiar and tested the vehicles characteristics. A company driver follow company instructions if it isn't unsafe.

That doesn't mean you are goofing up if you follow the tire manufacturers stamp. Like others said that lists max pressure.

More and more companies are increasing tire pressures to reduce rolling resistance and increase fuel mileage. With today's diesel prices it more than compensates the added tire wear. I wouldn't go over 120 psi myself. 130 psi seems a bit much.

 

This is ONLY a guess, but I would say they may have just ordered it that way because that is what all there other trucks run, while I do agree that in your case the taller 22.5 would be better, I have to admit that I like having as many things identical on my trucks as possible.

It makes things simpler, keeps costs down, carry less inventory, and is just simpler for the office to track, rather than a bunch of trucks with all different size tires.

With that being said, we only run 22.5/70's on two trailers, I can tell you we have more bent rims on those two trailers than my other 7 combined, watch out for big potholes, you don't have much cushion there.

We run 100 in our steers, BUT our front axle is always between 10,400 and 10,800 our 5th's are fixed and the KP is only 6" forward of axle CL, some our only change is fuel level.

BTW Chuck, how is she doing on MPG?