Just changed from a TT with 1200lb tongue weight to a fifth w approx 4000 pin weight. Haven't gotten to the scale yet. I'm confused.... placard on truck door says tires rated at 2660lbs at 65psi for rear duallies. Michelin load rating says 2778 at 80psi for duals. Should I inflate to 65or 80psi? Didn't have to think about this as much with only 1200lbs. Always kept it at 65.

I keep my front tires at 65psi and my rear tires at 80psi.

I stay at 80 all around on my Ram dually. 3100 pin weight.

There should be a rating stamped into your rims, the lesser of the rims or tires is the limit.

I can't run my rear tires at 80, or I lose the hubcaps. I lost three on the same bridge before I figured it out. Back to 65 as stated on the tires for dual tires, and I've kept my hubcaps for over a year driving the same bridge.

Rear tire pressure dually | Good Sam Community

Cummins12V98
Explorer III
Jul 18, 2015
webecreekin wrote:
Here are some pics. I don't like it when someone doubts my veracity.

Nice you posted a pic. So if what you are saying caused this bulge is true one would think there would be some type of line on the tire where it made contact with the other tire.

Did GoodYear tell you this was the cause, or General Motors?
Cummins12V98
Explorer III
Jul 18, 2015
webecreekin wrote:
Here are some pics. I don't like it when someone doubts my veracity. Please don't do it again.

WOW!!!

I guess the part of "not calling you a liar" did not get thru.

Just wanted to discuss the cause.
webecreekin
Explorer
Jul 18, 2015
Here are some pics. I don't like it when someone doubts my veracity.
Cummins12V98
Explorer III
Jul 18, 2015
webecreekin wrote:
Cummins12V98 wrote:
Mile High wrote:
webecreekin wrote:
I ran 65 in my rear tires with my pin weight at 3400 pounds and they rubbed together. The result after 600 miles was a big bulge in the sidewall of the tire. They weren't touching in a static setting, but while flexing going down the road, they were touching. Cost me four new tires. The inflation charts and the scientific approach don't mention the tires touching.

Wow, I had never heard of that.

I would say they were not the correct size tires.

Stock tires. In fact, they were the originals.

My first thought is how do you know they were touching?

The bulge could be from anything, just a bad tire.

Just does not make sense. My Dually tires with 60psi and over 5K sitting on the rear and closer to 6K don't even squat.

Not calling you a liar!
webecreekin
Explorer
Jul 18, 2015
Cummins12V98 wrote:
Mile High wrote:
webecreekin wrote:
I ran 65 in my rear tires with my pin weight at 3400 pounds and they rubbed together. The result after 600 miles was a big bulge in the sidewall of the tire. They weren't touching in a static setting, but while flexing going down the road, they were touching. Cost me four new tires. The inflation charts and the scientific approach don't mention the tires touching.

Wow, I had never heard of that.

I would say they were not the correct size tires.

Stock tires. In fact, they were the originals.
webecreekin
Explorer
Jul 18, 2015
Cummins12V98 wrote:
Mile High wrote:
webecreekin wrote:
I ran 65 in my rear tires with my pin weight at 3400 pounds and they rubbed together. The result after 600 miles was a big bulge in the sidewall of the tire. They weren't touching in a static setting, but while flexing going down the road, they were touching. Cost me four new tires. The inflation charts and the scientific approach don't mention the tires touching.

Wow, I had never heard of that.

I would say they were not the correct size tires.
Cummins12V98
Explorer III
Jul 17, 2015
Mile High wrote:
webecreekin wrote:
I ran 65 in my rear tires with my pin weight at 3400 pounds and they rubbed together. The result after 600 miles was a big bulge in the sidewall of the tire. They weren't touching in a static setting, but while flexing going down the road, they were touching. Cost me four new tires. The inflation charts and the scientific approach don't mention the tires touching.

Wow, I had never heard of that.

I would say they were not the correct size tires.
Cummins12V98
Explorer III
Jul 17, 2015
rhagfo wrote:
wandering1 wrote:
Follow what is on the tires, Michelin had a reason for putting that on the tires. What is on the door is wrong if it is not for the brand and size tires you have on the truck.

:S :S :S

The number on the sidewall is for the MAXIMUM LOAD, Michelin provides inflation charts for loads less than the Maximum the tire is designed to carry. Using the proper inflation for the load provides better wear and better traction and control!!!

Me thinks you be correct SIR!
Cummins12V98
Explorer III
Jul 17, 2015
I like pictures! I think a few of you may know that by now. I also like to give examples to backup what I have to say when I am able to.

Here are Michelin MS2's with 40K on them. I ran 45 psi rear unloaded and 60 loaded with 5K pin. The fronts always had 80psi. This was on my 2011 RAM Dually.

Weigh your rig! The fact is most people overinflated the rears and under inflate the fronts.

With my 2015 I am running 40psi on the rears solo because the rears on the 11 had "SLIGHTY" less tread in the centers than the edges on the rear tires running the above pressures.

My 15's front axle weighs 5,460# or 2,730# per tire. I could run 70 with little extra or 75 but with the edge wear the tires wear evenly at 80.
jadatis
Explorer
Jul 17, 2015
Though weighing per wheel( pair) or axle is the best way to determine the loads ,in lack of that you can use the Gross Axle weight rating of your rear axle of your towing truck.
For law you are not allowed to go over that , even when towing a 5th wheeler.
You can mostly find that on the same plate as the pressure advices.
From your tire we already know 2778lbs AT 80 psi for dual so E-load.
Need to know the speedcode .

From TT you gave dual load rear axle so 2 twinwheels on the axle.

But when you are busy also give details of front of TT and 5th wheelers tires and GAWR's and number of axles and total number of tires, Probably ST tires or else give speedcode too.

Then I will do the whole calculation and give advice with maximum reserve with acceptable comfort and gripp and no bumping