I'm going to be towing a trailer that weighs about 3K loaded. The max psi on the tires it 50psi. Should I fill it all the way up to 50psi? Also what should the truck tires psi be. I have the 23" Saleen wheels and the tire size is 305/40/23 and the max psi on these tires are 51psi. Should I inflate the truck tires to 51 or is 45 good enough. When not towing I run 35psi. I'm going to be towing from NYC to NC which is about an 8-9 hour trip.

 

Never fill to max psi. You could go up to 40 but the 35 is probably OK. Put the trailer on and take a look. I wouldn't go over 40ish though.

 

Hey pmason!

Glad to hear that you are going for that first tow!

No disrespect to what stocker06 is saying, but I don't agree with him.....

What I would do (and I do with my TT) is I would run the trailer at it's full (max cold psi) of 50.

For the truck, you have to be careful with those low pro tires, as they will build heat a lot faster then a 75 series LT rated tire will...

If the max cold psi is 51 for those tires, I would run 'em at 50....

Heat is what kills tires, and having too low of pressure will create more heat then having too high of pressure.

I used to run my trailer tires at the listed 35 psi (stupid "B" rated tires!). But, I also found out on Goodyears web site (the tires are the Goodyear Marathon ST tires) that you can go up to 10 psi over for what they quote as "high speed" driving...

Well, I did find that my tires ran pretty hot at 35.. When I bumped them up to 40 they ran cooler. This was confirmed with the tried and true hold hand on tire after a long road run method! In both cases, I could keep my hand on the tires, but the run at 40 and on a hotter day then when I did the same run at 35 the tires were noticably cooler...

I've been doing this for over 5 years now and I've yet to have a tire problem on the trailer or the truck.

Oh, I run my LT tires at 50 psi when I tow too. (that's the max cold psi for them).

I don't recommend you run your tires over the listed PSI rating, as at 50 psi, they are more then Likely "C" rated tires on the trailer and "P" rated on the truck....

Good luck and have a safe trip!

Mitch

 

Never? Why not?

When you are heavily loaded, there are many situations where the trailer and tow vehicle should be at or near max psi, IMO.

Sidewall flex due to insufficient air pressure is a real killer for tires and generates gobs of heat. Running at max psi will give you the lowest tire temperatures and the least likely chance for a heat related failure.

ETA: I 100% agree with Mitch, who posted while I was typing.

 

What he said......

Trailer tires are designed to run at maximum inflation....
Car/truck tires have different requirements which include steering and the contact patch of the tire and the road is determined by tire pressure and load.

Always run trailer tires at the maximum rated pressure listed on the side of the tire...

 

Thanks a lot everyone. Mitch I will take you advice. This past weekend I did a test run and I had 50psi in the truck tires (51 is the max) and 50 in the trailer tires (50 is the max) and it ran well. I will do this again tomorrow night when I leave and I will let you guys know how it went when I get to NC on Sat.

Once again thank you

 

Yes, fill your tires, no matter what they are on, to what the tires says on the side. Heat is what kills tires, but that heat will get there a lot faster if run too low. My new 10ply trailer tires call for 80psi, took me a while to get them that high but wow what a diff. And when pulling my box I put "what the tire calls for" on my truck, 50psi. And those are big BFG 35's but that is what they say, and that is what I do. Have I had a blow out?... no. Now empty I run them 40 up front and 35 in the back, truck is just too ruff at 50.

But hay, just call any tire shop and tell them you will be towing and see what they say.......

 

On my trip to Orlando, FL (1,200 miles round trip) I hauled my TT with truck and trailer at max psi (per mitch150's advice) and had no problems. I believe this to be better on your tires and better for fuel economy too.