Tire pressure when it's cold

I do 100 lbs just to be safe. 95 to 110. depends on the tire.

 

Michelin, Bridgestone and Yokohama all recommend around 80 PSI for 34,000#.

I have no idea where 100 PSI comes from.

 

lately iv been running my steers at 105 drives at 95 and trailers at 105. seems to be working good for me. i tend to be heavy 75k gross i consider light.

 

Everywhere I look it 's 100 PSI.
Except the tire manufacturer. 105 destroyed my last set of trailer tires. Now 80 PSI and a year latter they are perfect. Go figure.

 

Most tire manufacturers have a method to determine the "optimum" tire pressure for a given load. You'd be running a different pressure five times a day if you followed it to the letter. Most carriers determine a fleet-wide standard and stick to it.

Under inflated tires wear much faster than something that's set up right, and are more prone to blow-outs. Over-inflated tires wear faster, but not as badly as an under-inflated tire, and tires are designed to handle higher pressures as they heat up during the course of a driving day. You're probably better off over-inflated from that point of view.

Fuel economy is affected by tire inflation as well. An over-inflated tire is "stiffer" and won't heat as much as a under-inflated tire. It takes energy to heat those tires up, and that energy is produced by burning fuel in your engine.

IMO you're probably better off at 105 psi, than 75. But that's me.

 

I got the trailer at. 6 months old and tires were severely cupped on the shoulders. XTE I think they were. So I checked them- all at 105. Within 10 months I offered to buy the trailer and asked for a new set of tires in the deal since to originals were shot. I put on some XZA3+ blems and set them at 80 as per Michelin. They are wearing perfectly square 11 months later. If I can remember, I'll gauge them tomorrow and post here.

Edit : I just replaced some XDN2 on my tractor. 417,000 miles @ 80 PSI. no blowouts, no flats, 6/32" of tread left. Living in western Canada, I didn't want to chance going into winter with 6/32. Otherwise I would have tried for 450K.

 

XDN2's have the rolling resistance of a squared-off block of granite. The fuel cost to run them is astronomical, but yeah, you can run one set of them for nearly the life of the truck. At $4 a gallon, you could afford to buy a new set of X-One XDA Energy tires every year, and throw them away with cost savings in fuel alone.