What pressure are you guys putting in your LT-E rated tires on a 1/2 ton truck? My truck came with LT-C rated tires from the factory. There are very few C tires available in my size and the two I have used thus far have been disappointing. I bought some 10 ply tires yesterday and Discount put 40psi in them. That seems low.

Assuming you're running the same size tire, run what the door says regardless of load rating.

My understanding is load rating is only # of plys and sidewall strength.

PSI determines the size of your contact patch. So if you're running the same width tread, just in a stronger tire your contact patch with the ground needs to remain the same size.

Quick thought exercise... Your truck weighs 2000 lbs (round numbers) and the wight is evenly distributed. Each tire gets 500 lbs. If you're running 40 PSI (again easy math) you've got 12.5 in^2 of rubber on the ground at each tire. 50 lb / in^2 * 12.5 in^2 = 500 lbs.

If you jump up to 80 PSI because that's what that Load E tire says on the sidewall you're reducing your contact patch to 6.25in^2. Braking action and steering control are going to be seriously degraded and you're going to very quickly accelerate wear on the center of the tread. The stiffer sidewalls will lift the truck and the tread will bow out like a beachball.

Now if you put 1000lbs of cargo in the back of your 2000 lb truck and add an additional 500 lbs to each rear tire then YES you can boost the PSI in the rear tires while you're carrying the cargo.
500 lbs on each front tire @ 40 PSI = 12.5 in^2
1000 lbs on each rear tire @80 PSI = 12.5 in^2

EDIT... Again these numbers are for example only. I used round numbers for easy math and they are likely not indicative of actual weight distributions. An unloaded half ton truck will not have weight evenly distributed as in my initial numbers run.

I follow what the door says, even if my tires are larger than stock. I run 80 rear 60 front. In my older trucks I'll go 70 all around or lower if the ride is too harsh.

I run my F150s LT tires at 40-45. Running them at 70-80 PSI will knock your teeth out with the harsh ride.

If towing a camper or loading up truck for road trip with family of 5, I'll air up to 50-ish.

If just in running around town mode, I'll air down to 40-ish.

You can do two things


1. Chalk them
2. Look at the load capacity of the new tires per PSI and match them with the stock tires and that gives you the correct load rating.

This is one of my most frustrating topics as a former DTC employee… do NOT, EVER, under any circumstance, run your half ton tires at anything close to 80psi.

I am running Es on my 1/2 ton right now, only because the size I am running only came in an E. I have them at 40psi but I tow somewhat regularly with it. I could probably bump them to 45-50 in the rear when I do but I haven't found the need to do so and they're wearing just fine.

I'd sit 35-40 and you'll be just fine but if you're the "read the sidewall" type of guy, it's your truck and ride… just don't expect it to be good or your tires to wear normally.

Thanks for the replies. I was never considering anything close to 80. I just didn't want to damage the tires by putting too little air in them. I bumped up to 45 psi for a little peace on find.

For all you guys with E rated on half tons, even at low 40s PSI what is the ride quality like?

Ride is fine. Mpg drop sucks