Upgraded tires - air pressure?

[LoudDog]

I had load range D tires on my trailer that require 65 psi. They are the right load range for the trailer, but I wanted 10 ply so when it was time to change the tires I changed to load range E which is 80 psi.

The place I bought the tires from filled them to 65 psi (didn't notice until a few weeks later) but everything I am reading says always fill ST tires to the max.

So should I fill the tires based on trailer weight or the tire?

[bobndot]

Shal36 wrote:

wrgrs50s wrote:
I know there's charts out there by tire manufacturers that state that a tire only needs to be inflated to a point that matches it's load requirement but "hey" they get to sell you a new tire if it fails. I've yet to see any data that says a tire has been known to fail if inflated to the tire manufacturers suggested pressure stamped on the tire.

A different perspective...passenger car tires have a max pressure on them and thats what the stated load rating is based on. I have not seen any passenger vehicle where the recommended air pressure equals the max pressure. Of course, the recommended air pressure provides enough capacity to hit the vehicle's GVWR and provide good handling and ride quality. Best wear is typically at a pressure below max. In fact, if under max weight capacity but at max PSI, you are likely to see accelerated wear on the center. ST tires may be different, but I would suggest that max service life would come from inflating tires to match load weight plus some safety margin. If wear is a concern, the load pattern on the tire can be checked wi chalk or a pyrometer.

x2, that's how i look at it .


Most TT owners run out of time before mileage, not sure if it would be noticed with less miles or not.
I run my "C" 15" ST's at 45# and they are wearing fine at 6k miles.
I've been told by some owners of my model Jayco, that the OEM ST tires do show 'center wear' running them at 50# but they have more than 6k miles on them.
The reason i run a little lower pressure is because i'm running my TT below my axle and tire ratings. I often check my tire temp while on the road to make sure im doing things correctly.

P.S. i can't screw things up while on the road (in the truck's cab 10 hrs a day) because i have no 'man-cave' to hide in when things go wrong. :B

[CapriRacer]

Gotta correct a few things:

wrgrs50s wrote:
......... I know there's charts out there by tire manufacturers that state that a tire only needs to be inflated to a point that matches it's load requirement ......

All the charts out there are MINIMUMS, and none state that this is a recommendation nor do they state it is bad to inflate a bit over that minimum.

Shal36 wrote:
.... A different perspective...passenger car tires have a max pressure on them and thats what the stated load rating is based on. ..........

Not exactly. They state a maximum load and they state a maximum inflation pressure, but they normally don't state these are related.

[Shal36]

wrgrs50s wrote:
I know there's charts out there by tire manufacturers that state that a tire only needs to be inflated to a point that matches it's load requirement but "hey" they get to sell you a new tire if it fails. I've yet to see any data that says a tire has been known to fail if inflated to the tire manufacturers suggested pressure stamped on the tire.

A different perspective...passenger car tires have a max pressure on them and thats what the stated load rating is based on. I have not seen any passenger vehicle where the recommended air pressure equals the max pressure. Of course, the recommended air pressure provides enough capacity to hit the vehicle's GVWR and provide good handling and ride quality. Best wear is typically at a pressure below max. In fact, if under max weight capacity but at max PSI, you are likely to see accelerated wear on the center. ST tires may be different, but I would suggest that max service life would come from inflating tires to match load weight plus some safety margin. If wear is a concern, the load pattern on the tire can be checked wi chalk or a pyrometer.

[time2roll]

exploringcarolina wrote:
The aluminum wheels on our TT are rated for maximum of 60PSI. Our trailer was delivered new with 16" Light Truck BFG radial E tires rated for up to 80PSI. Could not find a load/pressure chart for my BFG tires, except for maximum pressure/load, but found a Michelin load/pressure chart for one of their 16" LT Radial E tires:

http://www.michelinrvtires.com/reference-materials/load-and-inflation-tables/#/

Is this a new trailer?
Does the tire size and pressure (60 psi) match what the GVWR sticker says to run?

Somebody might owe you some better wheels.

[Sam_Spade]

wrgrs50s wrote:
Running a tire below it's recommendd inflation is more likely to cause heat related failures.

THE NUMBER ON THE SIDEWALL IS NOT A RECOMMENDED PRESSURE......UNLESS YOU ARE CARRYING THE MAXIMUM RECOMMENDED LOAD.

I will keep repeating this until everyone understands.

Actually not likely as I probably will DIE before this myth ever gets fully dispelled. :R

[exploringcaroli]

The aluminum wheels on our TT are rated for maximum of 60PSI. Our trailer was delivered new with 16" Light Truck BFG radial E tires rated for up to 80PSI. Could not find a load/pressure chart for my BFG tires, except for maximum pressure/load, but found a Michelin load/pressure chart for one of their 16" LT Radial E tires:

http://www.michelinrvtires.com/reference-materials/load-and-inflation-tables/#/

[time2roll]

LoudDog wrote:
I could not find a psi rating on the rims, but they say max load 2830 lbs which matches the E tires, they are 6 lug too.

Yea you are good to go on 80 psi.

65 psi automotive stem:



80 psi snap in stem:

Metal is good to 80+

[LoudDog]

I could not find a psi rating on the rims, but they say max load 2830 lbs which matches the E tires, they are 6 lug too.

[rbpru]

I will note that one of my new D rated was shredded by a rim bending road hazard.

Road hazards do not care what the tire rating is.

[rbpru]

My axels are rated for 7000 lbs.

My C rated tires were good for 7140 lbs. A bit to close for me.

My D rated tires are good for 8160 lbs.

[wrgrs50s]

I was told by my wheel manufacturer that if you have 5 lug rims the recommended pressure is 65psi and that 6 lugs are good for 80psi.

I have 6 lugs and upgraded to E tires and run 80psi for the last 5 yrs, with no problems. It dont make sense to me to upgrade to an e tire and not take advantage of the additional load capacity. Running a tire below it's recommendd inflation is more likely to cause heat related failures.

I know there's charts out there by tire manufacturers that state that a tire only needs to be inflated to a point that matches it's load requirement but "hey" they get to sell you a new tire if it fails. I've yet to see any data that says a tire has been known to fail if inflated to the tire manufacturers suggested pressure stamped on the tire.

[Lwiddis]

Ksg, I know of no recommendation that TT tires not be inflated cold to max sidewall pressure. In my case LR D is 65 psi. And Lady agrees...she must be running LR Es.

[LadyRVer]

When the tire shop upgraded the load range for my new tires, they aired the new tires from 65psi to 80psi as stated on the new tire. I have towed with the 80psi for 18 mo . now.

[Huntindog]

One thing to consider, especially for ST tires which generally have a bad reputation for reliability... In the case of a blowout, If you only have 65 psi in the tires, the remaining tire will most likely be severely overloaded.
To the point that it should be considered damaged and replaced along with the blowout.
If 80 psi is used, the overload (if any) will be a lot less. In my case, I would take it out of service, but use it for a spare.

Blowouts on TTs are problematic. Often they go unnoticed for many miles. The TT usually doesn't tow much different. So lots of damage can be done. Both to a remaining overloaded tire, and to the TT from the steel belts whipping around acting like a chainsaw on the TT.

This why I use Michelin XPS RIBS. Very expensive, and VERY reliable.