ok thanks bro I will have to try it and see

 

To clarify though, you need to max out the PSI with the trailer already attached. Don't max them out and then attach the heavy load. Also, if the trailer weight is not seriously heavy then you likely do not have to max out the tires, doing so will only lessen the ride quality.

 

What do you guys mean by max tire pressure? I sure hope its not the max label on the side of the tires. That would be way too high, and very dangerous. There isn't really a range for tire pressure, there is just a target number, on the drivers door, and a small tolerance, if I remember correctly. Inflate to that number on flat ground before loading up the truck. The truck is designed to operate at capacity with the listed tire pressure on the door sticker.

 

Sorry man but everything you just said is wrong.

Toyota installed a little button under your steering wheel that resets your TPMS. This is there for when you switch to a tire that is different than OEM specs so that you can fill the new tires to the recommended PSI and then reset the TPMS system to monitor the new PSI settings.

The PSI rating on your door is based on the tires your truck came with and there is also a note on that sticker that says to see your owners manual for more information. When you look in your owners manual it will clearly spell out what I am saying.

If you run 33" Terra Grapplers at the 30/33 PSI listed on your door then you will ruin those tires in no time and they will look obviously flat. All tires are not created equal. The MAX PSI rating on your tire is exactly that, it is the Maximum PSI you should have in your tire when cold. That number takes into account that the pressure will go up when you drive and that is ok. If you towed a heavy weight using the same PSI you use for daily driving then the weight will push the tire down to the point where you are driving on your sidewalls, hence, you increase PSI accordingly for the amount of load on them.

 

Ok, now I'm confused. I haven't looked at tires too in depth, but I can assure you I will now. I was under the impression that the max pressure label was on the tire in order to inform the operator the maximum amount of pressure the tire can safely hold and operate at. And i do understand that with different compounds and tire class, the psi will have to be adjusted accordingly. But I can't understand why if you air up when loaded, how is that not equal to being over the recommended PSI when unloaded? Its not like the PSI will go down when you add weight, so you have to add more air. The PSI should actually go up when weight is added to the vehicle. That's why everything should be measured unloaded. It gives an even point of reference.

reineduro, I'm sorry man, I thought I was helping. Didn't mean to derail the thread. These guys are much more experienced than I am, listen to them. Now I'm just trying to understand why i was misinformed. I was under the impression I knew what was up, but I should have known better, lol.

 

I always keep my tires 5-10 psi over their max rating. I have always done this on every vehicle I've owned and never had any problems. My thinking is that manufactuers print lower max pressures on their tires to save themselves from liability even though the tire could prolly handle much more. I could be wrong, but like I said I've never had any problems and enjoy the feel and ride of an "over-inflated" tire.

 

Do you do this all the time or only when towing? If you do it all the time it will usually result in a very stiff ride and uneven tire wear (the middle of the tire will wear more quickly than the sides). The Max rating is just that, the maximum and it is not recommended for everyday driving...but, if you are not having problems and enjoy the ride then I guess it's no-harm-no-foul.

 

Wow. Reading this thread could make your head explode.

42 psi is 42 psi, whether there is a load in the truck or not.
Do not air up to the max tire psi rating just because you have a load. Add the amount of air needed for the load.
The psi numbers inside the door are the recommended psi for the stock tires when unloaded. But those numbers are still too low for stock tires.
Do not exceed the max rated psi on the tire regardless of how many times you have done it in the past. First, you could blow the tire, wreck, and take out other people. Second, you will wear down the middle of the tire prematurely. Third, it creates a poor contact patch on the road giving you LESS control of the vehicle.

Do like 2010CrewMaxTRD said and look at the tires when unloaded. Then load everything and air up the tires to look the same as when unloaded (without exceeding the max rating). Write those pressures down somewhere so you know what pressures to use next time you have the same or similar load.

 

Old thread but I'm reading it and wanted to add. When unloaded I typically run less psi in the rear so I don't wear out the middle of my tire usually around 28 to 30 PSI. Pretty much going for the similar bulge as the front. I always thought the PSI rating for the front tires was ridiculous being lower than the rears. I was running 35 in the front but was getting a little extra edge wear. Just bumped the fronts up to 40 PSI going to see how that feels. Stock LTX At2 Michelin's 51 psi max. I do like the air down when going in the dirt, need to invest in a compressor so I can air back up. I have ran similar air pressure in previous trucks that I have had and found this to be a good baseline. Between 36 and 40 psi in the front and 25 to 32 in the rear unloaded. Always had very even wear. For me running the same PSI all the way around just caused weird wear issues that I did not like, fronts wear out on the edges, rears wear out in the center. But this was always on LT tires.