Tire PSI

classic 31 wrote:
My door sticker says front 50lbs and rear 80 lbs owners manual said this pressure is good up to the max gvwr 8600lb The tires are LT 245/75R16 tireS are rated to 80 lbs truck is loaded and has a very good ride with this pressure. 30 lbs less than the max of 80 on the front.

Most people will run -20 lbs "around town", which is what I do. There's no need to run around at 80 psi. I'll tow, for short distances, at 60, but at surface street speeds and not far. I'd recommend dropping your pressure when not towing, as your tires will have a larger contact patch with the lower pressure. Heat's not an issue with no load at those pressures.

Lyle

The trailers tires are very simple.
I like this from;
rvsafety.com

Tire Load and Inflation Ratings

**Note: Towable – Travel Trailer/ 5th Wheel owners Due to the severe use conditions experienced by tires when axles are very close together – tire industry experts recommend maximum (sidewall) inflation pressure for towable tires unless this causes a sever over-inflation situation (20psi+), often referred to as the ‘basketball effect’. If this is your situation allow a 10 – 15psi safety margin above the minimum required inflation pressure.**

Truck tires don't operate in the same environment as do the trailers tires so we can use psi for the load carried.
My 2500 Dodge/Cummins for example has LT265/70-17 E tires. I've weighed my trucks axle empty and loaded so I know how much psi they need.
65 psi in the front when towing or running empty.
In the rear 70 psi works best carrying a max axle load and 45 psi when empty. As I said these are my figures and won't work for everyone.

Weigh the trucks front and rear axle before and after hooking the trailer. Then use the tire mfg pressure chart for your size tires.

grizz02 wrote:


My sidewalls on truck and 5th wheel say max cold psi 110........

Would guess there are TWO questions here: Your truck -&- Your trailer

TRUCK: - From your other post, doesn't appear your truck tires require 110 psi.
Usually the factory supplied (as well as after market) p/up truck tires will have a max psi of 80 lbs.
Inflate to what the door sticker indicates.

However - for the REAR tires on the truck, when running with an empty bed (not towing) - lowering the pressure in the REAR tires will result in an improved ride.
Your option on that one - "buckboard" ride or not.
Remember to increase the pressure in the rears before towing.

TRAILER: Inflate to the max psi as indicated on the sidewall.
However, you may choose to reduce that (ex: 10 psi) for an improved ride. Again, your option.

To determine the EXACT load on each of the trailer tires, you need to weigh the trlr as posters have suggested.

"COLD" - simply means *before* the vehicle (truck or trailer) has been driven on the road.

:C

Just did that everything says 50lbs in front is fine door sticker owners manual and tire manufacturer tires will carry 2205 lbs each at 50 lbs I have a 4000lb axel.cat scale shows 3520 lbs. ft axel.

You need to do 3 things - -
#1 - find a scale and belly up, loaded for your longest trip with fluids if you may ever travel with them

#2 - find the load capacity chart of your tire manufacturer

#3 - Read and compare.....

What tires do you have on your truck? Are you SURE max cold PSI is 110?

grizz02 wrote:
Is there anyone that has any real info on tire psi. I have talked with people I bought the tires from and looked on internet and still don't know the right answer . My sidewalls on truck and 5th wheel say max cold psi 110 I am wondering is that smart to do on long haul alot of time in hot weather do to heat build up they say 110 I run them at 85 psi. anyone have any thoughts on this and any real info. thank you for your time to respond on this

We need a whole lot more information before anyone can give you a good answer!!

#1. We need weights as Dono128 stated, at least weights by axles of both the TV and trailer If your tires have sidewall pressure of 110psi, you are likely running F or G rated tires on both.
This tells me you are either wanting a stronger tire, or running a LOT of weight.
If not running a lot of weight then, if you inflate to 110 psi, there will be in reality OVER INFLATED for the load being carried, and will have a smaller contact patch on the road. Sure they will run cooler, but if you drive on wet roads you will have far less traction for stopping and steering!

You will fine there is two inflation camps on this forum.

1. Always inflate to max sidewall pressure, no matter the load carried, or the weight rating of the tire.

2. Those that inflate to a pressure that will carry the load on the tire. Example the rear tires on TV are rated at 3,415#, I carry loaded with 5er at about 5,600# so run at 75 psi, not 80 psi. Fronts carry about 4,500# so about 60 psi. Max sidewall pressure is 80 psi.

grizz02 wrote:
Is there anyone that has any real info on tire psi. I have talked with people I bought the tires from and looked on internet and still don't know the right answer . My sidewalls on truck and 5th wheel say max cold psi 110 I am wondering is that smart to do on long haul alot of time in hot weather do to heat build up they say 110 I run them at 85 psi. anyone have any thoughts on this and any real info. thank you for your time to respond on this

Are those factory size and load range tires? If so refer to your GVWR sticker or owners manual. Please post what it says.

If those are oversize or higher load range tires then you should get the inflation from the manufacturers load chart.

If you need help looking all that up... you need to provide the exact tire brand and size along with the vehicle and trailer GVWR and GAWR numbers. Also need the wheel brand, model and size to verify load and pressure ratings meet the higher tire load and pressure ratings.

Otherwise the numbers are a bit random. However 110 psi cold will never hurt a tire rated 110 psi in any conditions. Never reduce pressure due to temperature conditions. Cold means in the morning before you roll and before the sun hits the tires.

My truck sticker says Front 60, Rear 45 empty, 75 loaded. I run Front 60, Rear 50 unloaded because I always seem to have something in the back and 80 loaded which is sidewall.

I run 80 in my E trailer tires which is sidewall.

Most fifth wheel tires are not evenly loaded as one side is usually heavier than the other and front to rear loading can also vary for different reasons. Grand Design weighs every trailer and includes a weight sheet in the documentation. Empty, my left side trailer tires are carrying 600 lbs more than the right and as most inside storage is also on the left side, it is probably closer to 900 lbs loaded.

Remember that manufacturer's load inflation charts are just giving you the maximum load rating for different pressures, they are not recommended pressures. The reason tires are lower weight rated at lower pressures is because they generate more heat. Where you set your pressures is a matter of your own comfort level. I err on the side of more capacity

Most roads in America suck! Running at max psi if not required just beats the **** out of your trailer.