2019 Toyota Tundra Heavy Towing Question

Hi name is Kevin, I own a 2019 Toyota Tundra SR5 Crewmax TRD OffRoad 4x4 that has 66,000 miles on her I bought her in February of 2019 with 4 miles and have the Tow Haul package
Towing Captivity Is about 9,200. My tires are 275/65/R18 Michelin LTX A/T2 114T and I just bought new tires today and changed the spare to a newer 2021 that I had a 2019 year made tire.
I also Own a 3,000 QB 36 Foot Travel Trailer that weighs full time 8,900 with all my stuff inside. Fun fact hitch weight 795LBS. Being that I'm a full timer that is. I usually pull it every other week for about a week or two. I also towed the trailer since September 19th of 2019 and I use an equalizer 4 trailer Hitch that helps with the weight distribution and sway.
So my question is Tire Pressure. I have the tire pressure full time 34 front and 38 rear cold. I never change it even while un hooked. What do you think? What should the tire pressure be Hooked up and unhooked. Please help.

 

Tire pressure is going to vary based on the tire and it's load rating. Were I in your shoes, towing at or close to max, I would put my tires 5-10 PSI shy of the max cold PSI on the sidewall. See how she feels, and go from there.

 

Azure, what do you think the right pressure? 35 36? Please.

 

Again, it depends on the tire you have. Some truck tires have a max rating of 80 PSI, some far less. Without knowing the tire and it's ratings, it would be bad juju to recommend a number. give me a minute to look up the tires.

 

I believe the stock Michelin's have a max of 51 PSI.

OP since you're going to be pushing not only max tow, but max payload I'd be looking into airbags to help take some of the weight off the leafs.

 

I have a Equalizer 4 Sway Bar that helps

 

Ok, so some quick google-fu and I got this:







Looks like your max COLD PSI is 51, and your total load capacity on 4 of these tires is 10,404 lbs. If you are within the total weight capacity (NOT JUST WHAT IS ADVERTISED. YOU NEED TO SCALE YOUR TRUCK FOR REAL NUMBERS) while loaded and you keep your speeds down you should be within spec. Personally, I wouldn't pull a trailer the size you have with any 1/2 ton truck. I just think it's too long and heavy for a light duty truck. If I were forced to tow it I'd start this tire out at 45 PSI to handle a heavier load like that, and wouldn't tow over 50-60 MPH with a large trailer. Definitely use a WDH.

Again, this advice is worth what you are paying for it, and you should see if you can find PSI recommendations from the tire manufacturer. My personal recommendation would be to get a smaller trailer or a bigger truck.

 

Thank you both.

 

@2019TundraSR5 Your max load is 2601 lbs and max pressure is 51psi. With that weight on the rear, I'd start at 45 and go +/- based on how stiff it felt.

I know my LT tires can feel like rocks when I get to higher pressures.

Question for you: do you monitor your transmission temps? I would be FAR more worried about my transmission than my tires towing that much weight without a trans cooler.

Edit: was typing while @AzureNightmare posted the same info!

 

I cant monitor my transmission because the 2019 doesn't have a way to monitor it. I do get my fluids checked every time. And the last millage is 65,000 on black beauty and she gets her oil changed every 5,000 miles I never go without 5,000 mile oil changes

 

Air bags don't take any weight off of anything, though...... They just lift the ass end up. The weight is still on all the same components. Air bags can give a cushy ride, and help with the cosmetics of a sagging rear, but they don't actually do anything to improve weight handling.

 

Look up transmission cooler in the search bar at the top right. Check the box for "search titles only". This is a huge deal on this forum; most everyone has strong opinions one way or the other. Your truck does not have an external transmission cooler up front. Toyota deleted it from the Tundra in 2019. The transmission was designed to handle higher temps, and for most on here who don't tow, it probably won't be an issue. But there are a couple examples of failed transmissions at this point (I personally think we'll see more after in a few years after everyone's warranties are up) and at least one anonymous Toyota engineer who criticized the decision.

I'd get an OBD scanner and an app for your phone to monitor it. If you spend much time north of 220ºF at the pan, and I would all but guarantee you do towing that much weight, you should think about installing a cooler.

 

Ok. Thank you. I will go out this week and buy a monitor

 

You're Scaring me tern. I have the 120,000 mile warranty. I made sure of it.

 

Put enough pressure in them and you take some weight off the leafs, and those are the weak link in the Tundra and it's payload. By doing this you get more weight put onto the front axle. Getting rid of the sagging is the big issue with the Tundra, all the other components outside the shit leafs can handle lots more weight. Fix the leafs and I bet the Tundra could be rated for 2000 lbs payload.

 

Stock tires i run 43-45 front always. 35 rear empty, 45 rear towing my 4000lb trailer. Works perfect

 

Because of where they mount you are essentially pressing down on the rear axle to lift the springs up a bit to shift the weight. You are directly loading the rear axle and by tilting the frame you will put some weight back on the front axle. The WDH the OP has will already evenly distribute this weight if properly set up, so airbags become nothing more than added weight and a tool for comfort/plush ride. They have their place, but they aren't going to help with a heavy load as much as a WDH with antisway will.




I agree the narrow leaf springs are a weak point when it comes to payload; they are not THE weak point, and I don't think putting in better ones wouldn't help your payload ratings as much as you claim. The payload rating isn't for a static load, it's for dynamic use on the road. How it will handle bumps, dips, turns, acceleration, and braking all play a part in that rating. Heck, the cooling ability of the truck plays a part in its ratings. There are a multitude of factors and systems that go into the payload and tow ratings, so saying that a single component change is going to net a 50% or better payload increase is disingenuous at best.

 

Isnt anyone going to ask what gear he tows in?

 

That's easy, I'm pretty sure 5th and 6th are 2 second intervals! Lol , The truck lives in 4th..

 

Get the monitor and use it. I would be very interested to see your temps. I just ordered the cooler kit and i only tow a car trailer with a 4whlr and SxS. Empty mine runs 230 on the highway.

 

The axles are rated for something north of 8000 lbs combined while the GVWR is around 7000, and towing 9000 lbs is a hell of a lot harder than hauling 2000 lbs on cooling. All that's left is the suspension and frame - maybe the frame isn't up to snuff for day in day out of 2000 lbs, but I can verify the Tundra handles 2200 lbs in the bed VERY well for braking, turns, and bumps, even with how much it sags. Throw on some stiffer leafs and I would be comfortable driving with that weight at highway speed. I thought for sure doing that I would have poor braking, it would handle like a boat, but it did neither. I gave myself a lot of room for braking and it stopped just the same as having a 6000lb trailer behind it.

OP is staying within the specs, barely, so anything to help get the weight onto the front axles is a good thing. They're already using a WDH and adding air bags will only help. It won't be a ton, but in my experience a heavy trailer will get a Tundra to sag 2"+ even with a WDH, so add in the air bags and gaining even just an inch will help. They don't take long to install, don't impede normal function, and definitely help stabilize the truck so why not add them?

 

I'll take a picture when I'm hooked up next time and add it. I'll even take a close up picture of the sagging.

 

Just throwing this out there, your weight is very different then mine. I run 44psi all the way around towing 3000 lbs.

 

230 at what speed ? Flat ? Outside temp ?
I get the same temp towing or not which is 215 on pan (4000lb travel trailer)
The difference is while towing , I have it on s4 , tow haul and keep speed between 55 and 60 .

 

I was running 80-85 on flat interstate. Air temps 65-70. It was certainly higher than i expected. My f250 didnt get up that high except for stop an go in mountains with a load.

 

Let us know what temp you get once you set up the odb2

 

WHAT IS THE CORRECT PSI WHEN UNHOOKED FROM TRAILER WHEN PARKING TRAILER????

 

Just bought these new tires and want to keep them for a good time. Please.
Whats best psi when not towing on these tires?

 

You won’t like my answer, whatever you want them to be, buy some tire covers and stop overthinking it.