Tire Pressure Towing

2017 SR5+ DC, TRD package with Michelin LTX-AT2 tires, 275/65-18. 114T rated, believe that’s 6-ply. Maximum pressure listed on tire is 51 psi. Will be towing a 7500# TT 100 miles, 5500’ elevation gain.
What would you run for air pressure? I’m thinking 45 rear, 40 front?
I wish I’d thought when taking delivery to have them upgrade tires to 8-ply, I have 30K on tires and will upgrade when they wear out but for now I’m wondering what the consensus here is.

 

If max is 51, I would set pressure no higher than 40, you’ll get 4-5 psi increase from heat alone. You certainly don’t want to be pushing the tire to the limits while in tow.

 

33 is rear pressure for stock...so I agree, no more than 40 should be plenty.

 

I think either 40 or 45 would probably be fine. Even running 50 in the rear wouldn't hurt anything and might be advisable depending on the weight. Tire max psi ratings give are given as a cold rating meaning the increase in pressure as the tire heats up is accounted for in the stated rating. It is also important to know the tire can only carry the max weight rating when inflated to the max psi. As you drop the psi, you lose carrying capacity. This is why most recommend running trailer tires at their max psi until you get to at least 12 ply. People that run trailer tires at 30 psi for a softer ride are the ones you see broke down on the side of the road after their china-bomb tire exploded from overheating and shoulder failure.

@Scuba is the resident tire guy... maybe he can give his thoughts on this.

I think the bigger question is what is the tongue weight? If you are really concerned about hauling this you should hit a Cat scale before you go to see if you are over capacity on the rear axle and/or rear tires. Having the WDH hitch properly adjusted could be the difference between being over capacity or not.

 

Thanks to all, not worried about tongue weight as it’s being towed empty, one time to some property where it’s going to stay. Previous owner towed it loaded with a 2010 Tundra. I do have a good WD hitch.

 

Max tire pressures are when they are cold anyway, so going to 50 cold is not an issue. They are built to handle the increase, not to mention a generous safety factor.
Tire max weights are at their maximum pressure too, so you'll definitely want to increase it when towing/hauling. I increased mine from 35 to 45, and saw uneven wear (as if they were under-inflated) on my cross-country trip. If I did it again, I'd bump it to the max, 50.

 

With 2017 Limited DC, also tow TT weighing about 7500 lbs with those tires - run both front and back at 42psi. When not towing, I drop them down to recommended pressure.

 

Hello. First time user. Still not clear on psi. I have 2015 Tundra with LT Bridgestone Dweller. I will be towing bumper pull 5500#'s in AZ. What is good psi front and back, Winter and Summer. Not so much in Summer. Thank you in advance.

 

I think the LT Duelers (275-65-18?) are Load Range E Tires but please confirm max pressure on the tire sidewall. If 80 psi, I would suggest 80% of that value or 64 psi. All the way around....all the time when towing. I run 42-45psi on max pressure 51psi tires.

 

Yes, I saw E rated. If I was looking in the right spot, said 80 psi cold

 

So what do I run them at when normal driving. I understand when someone gives me an answer without out confusing the issue, so, thank you.

 

E rated tires are good. That is what I will buy when I need to replace my current tires. I would run 80 psi max tires at 64 psi cold with your size trailer. You could run them higher but I think that's plenty of pressure with a 5500# trailer. You could increase further if you think you are feeling signficant sway.

 

I think I would run them at 50 psi min. You could run them at 64 psi but 50 psi would provide better ride quality. I don't have E rated so haven't crossed that bridge yet. Maybe someone else will chime in.

 

Thank you so much Buckaroo. I really appreciate it. Seems the more I Google, the more confused I get.

 

2019 Limited Crewmax here with same stock Michelin LTX-AT2 tires, 275/65-18 with TRD rear sway bar installed.
I also tow a 7500lb TT and, in last couple trips, I towed with 41 psi front and back. I tried different combinations and feel this is a right combination for me for now.

Based on my little experience with only couple thousand miles in towing, 45psi or more cold at rear is a bit too much for me and it cause the rear to be very “bouncy”.(not sure if it’s the right term??)
I might try 41/42 next time to see if it makes any difference.

Jason