Okay guys I'm looking to see what you all are keeping tire pressure at.
I did a level & wheel spacers along with new tires.
I went with LT275/70/18 GoodYear Wrangler Adventure's with kevlar on my stock wheels & the shop set them all to 75 PSI.

 

check with Goodyear to determine tire pressure based on load capacity.... there is a conversion from Passenger tire to Light Truck LT.

 

I got Toyo AT II's in 285/65/18 and set them to 45 PSI using Toyo's chart. As Thugzy mentioned, check Goodyear's website for the conversion and weight/load. Also, Costco near me said the same thing, 45 PSI for the LT Toyo's (just wanted to double check), so maybe ask them too?

 

75?? Figured that was a misprint.

For everyday driving I think you'll find around 36-40psi to be the sweet spot. As you increase the load or tow then you'll want to bring the psi up. Maxing out the payload and towing 5-6K lbs I still can't imagine running past 60 psi.

 

I've tried several pressures for all terrain LT tires on my big SUV and now F150, settled on 40-42 PSI cold

There's no rhyme or reason to be at 75 PSI on a half ton truck, that's just insane. Seems like it would be tooth rattling-ly taught

 

I just got rid of the same tire in LT275/65/18's due to a runout issue. I was running 39lbs.

 

The right answer that provides an answer unique to your situation and truck is the chalk test.

 

So here is one of the ways you can figure out how much air to run in your tires.

1. Weigh your truck; front tires on the scale then rear tires on the scale.
2. Read the max psi @ what weight on the side of the tire. Something like 3250lbs @ 60psi, (just an example).
3. Divide the weight by the pressure, in this case it would be 3250/60=54.1 So, every pound of air pressure holds 54.1 pounds of truck.
4. Take your trucks front weight and divide it by 54.1. IE: trucks weighs 3500 lbs on the front tires, so... 3500/54.1=64.7 so that would be 64.7 psi. Divide that by 2, since you have 2 front tires, 33 psi.
5. Your tires need AT LEAST 33psi to hold up the front weight of your truck. Take this number and add a few pounds for security reasons and see how your tires wear.
6. Do the same for the rear. Yes, you will run a lot less in the rear tires when the truck is unloaded.

You can run more air in them if you like, but DO NOT run less than this number that you come up with. I do this with all of my trucks and my tire guy is always amazed at the mileage I get out of my tires.

Good luck!

David

 

75 ibs. more than likely is above the rated max pressure for the tires, unless they are 8 or 10 ply, and then there is the max rating for the wheels to consider. I think Goodyear just signed off on a lawsuit with that kind of action. I run 65 lbs in my F-250, and in the travel trailer tires. 8 and 10 ply respectively. These are manufacturers recommendations. Like one member said, bone rattling, plus very negative to the health of the overall truck. Don't complain about squeeks and rattles later on.

 

He told us what tires they are. You could look them up.

LT275/70/18 GoodYear Wrangler Adventure

https://www.tirerack.com/tires/tires...tnum=77SR8WATA

Load Range: E. Max PSI: 80


That max is clearly not relevant to a half ton, of course.