Front and rear tire pressures with travel trailer?

hi all, we've purchased a new-to-us travel trailer with GVWR 9500 lbs, tongue 750 lbs. Dry is 6200 lbs so we'll probably be in the 7500-8000 lb range fully loaded.

Trying to figure out best tire pressure to run fronts and rears at.

2008 Tundra SR5 Crew Cab 4x4, which I think is rated for ~10,000 lbs.

Tires are 305/60/18 E load tires rated for 3500 lbs @ 65 psi. AMP Gripper. I can't find a load/inflation chart for them anywhere. Rims are Fuel Shok rated for 2500 lbs (picked to match the truck max).

Obviously I don't need to run the tires at full pressure. Based on Toyo load/inflation for the same tire size, it looks like 50 psi would be the best for the truck and trailer weight. ( https://www.toyotires.com/media/3729/application_of_load_inflation_tables_20200723.pdf ) <-- it's a pdf ...

I have airbags in back but for this conversation I don't think it matters. I'll be using a load leveling hitch and sway bar, but again I don't think it matters for this question...

Truck is leveled, but not lifted. receiver is at stock height...

 

I would use the toyo chart as a good starting point. Keep an eye on wear and temperatures.
Could do the chalk test to confirm the contact patch

 

50psi is what I concluded my E rated tires should be at, minimum, if towing (40ps if empty.) However I settled on 65psi in order to compromise between comfort and more capacity. 65psi is always what I run in my trailer tires so it's easy to remember. Truck tires are 80psi max but they're pretty harsh at that level.

 

I always ran my truck and toy hauler right around max PSI when towing especially in summer when going through areas that have 120°F plus temperatures. Changing a blowout in that heat sucks!

 

Running over the necessary psi implies more pressure is better... Is that actually true or am I reading wrong? I would think wear would maybe be uneven (LT not trailer) if you're over the needed psi...?? I'm just trying to understand because I'm new.

Good suggestion on the chalk test. I learned about that after posting my q as I read more. Thanks.

Trailer tires are E rated and from what I read max psi is 80 but 65 is what's needed for the GVWR... But I've read lots of common wisdom saying run trailer tires at max. It's a wide spaced axle trailer so I could see higher pressures responding better to low speed sharper turns and scrubbing ... At the expense of a bouncer tow. Thoughts on that too?

 

Basically in a nutshell. More pressure equals less rolling resistance which in turn equals a cooler tire. Overheating tires due to low pressure is a major contributor to trailer tire blowouts. You can actually run over the max PSI but the load rating of the tire is lowered the more you go over max PSI.

 

The higher the pressure the closer to the max weight I believe you mean.

keeping the proper contact patch is ultimately the most important factor. Too little pressure leads to shoulder wear, and high temperatures. To much pressure gives you crown wear and harsh ride.

both also contribute to poor at-the-limit handling. In an emergency you want the tires to have the most grip that they can.

I would recommend the manufacturer chart, or the chalk test.

 

Max PSI is for the max weight rating of the tire. Going above or below the max PSI will lower the weight rating. I'm not suggesting than anyone purposefully run over the max PSI but more stating it is not bad if your PSI is a little over. People seem to be afraid of running max PSI. It's completely safe and recommended by most for trailer tires. On my last set of ST tires I traveled about 10k miles with no issues using this method. This was on a toy hauler the weighed about 8-9k depending on what was loaded and I usually ran between 65 - 80mph. I've also never had an issue with the contact patch on my ST tires. They are such flexible tires. Again this is all from my experience and other people I know that have heavy trailers. Not saying I am the expert or know all of everything. Just figured I'd put in my experience

 

I was referencing the OP’s question which was in reference to LT tires, the same goes for passenger tires.

ST tires are an entirely different animal and should always run at the pressure molded in sidewall.

 

Great info here, thanks for all your thoughts and comments!

 

Ah I think I misread the OPs post. He said 50 PSI for the truck and trailer so I went down the rabbit hole of trailer tires. Yes I completely agree with you on LT tires. Contact patch is very important especially for the steering tires. I had great success with close to max PSI on my truck tires but this was also on my diesel. Every truck is different for sure. OP ignore all my rambling unless you want info on trailer tires. Lol

 

Well I read my original post again and I could have been more clear. I was referring to the truck tires originally, but got some great info on the trailer tires too, so thanks!

 

Run my 10 ply tires @ 40 psi cold when not towing
Air them up to 50 psi cold when towing my camper .

Call the company who makes your specific tire and ask , I've found every manufacturer will have its own recommendation for inflation pressure

 

This will also give you a staring point. Enter original tire and your new tire and it spits out a pressure to hit the same load rating