Tire pressure difference on rear duals?

[FreshAir]

I have noticed on my tire pressure monitoring system that on the rear duals the inner tires run about 4 to 6 lbs. higher pressure than the outside tires at highway speeds. I attribute this to increased tire temps on the inside.

My question is, I'm wondering if it would be adviseable to increase the outside tire pressure by a few pounds more than the inside to compensate for highway running? I read on a previous post that the duals should be within 1 pound of each other. Maybe it doesn't matter? Maybe that's why they make Equalizer systems???

Pat

[FreshAir]

I have noticed on my tire pressure monitoring system that on the rear duals the inner tires run about 4 to 6 lbs. higher pressure than the outside tires at highway speeds. I attribute this to increased tire temps on the inside.

My question is, I'm wondering if it would be adviseable to increase the outside tire pressure by a few pounds more than the inside to compensate for highway running? I read on a previous post that the duals should be within 1 pound of each other. Maybe it doesn't matter? Maybe that's why they make Equalizer systems???

Pat

[Fred and Bonnie]

It is my understanding that the inner dual carries more weight, therefore the additional temperature. I would stick with the procedure of inflating at cold temps to the correct PSI for the weight carried on the axle.

Fred

[MikeT]

My tires run equal hot or cold, maybe you have other issues --- My tire pressure runs higher at highway speeds, but they are within 1 lb. of each other.

[FreshAir]

Been doing some reading on this dual tire thing. Looks like I have a normal problem. I'm now leaning toward a small pressure increase in the outside duals for some compensation. The WH W24 has an extra set of brake calipers and maybe they have a tendency to generate a little more heat, less air circulation. Here's a ouote from Cross Fire.

" Tires
Dual tires have a set of problems all their own. In motion, the inner tire's temperature increases due to in-board brakes and poor air circulation. This causes increased air pressure, which expands the inner tire's diameter. As a result, the dual tire configuration is now distorted- the diameters are unequal."
Cross Fire

Pat

[John-D]

You might consider crossfire adapters. However if you don't, I'd go with the tire company recommendatios My duals are within 1 PSI cold as of last check (last time I drove it)

And I'm unable to install Crossfires on my rig (NOTE: What I can not do, others with smaller hands may be able to do easily)

[scoutmstr]

This will cause no end to speculation but years ago an article was written on running the outer rears 5 lbs more than the inner rears. Two reasons were given; one is heat on inner duals and the other was to reduce scrubbing on turns (although slight adds up over time). Being running that way for 17 years and over 70000 miles with no adverse effects. No blowouts, no tire failures.

[DriVer]

I am of the opinion that all the duals (4) need to be inflated to the same pressure.

I have spoken with the major tire reps at RV shows and not once did they suggest dissimilar pressures on the same axle.

[Tom N]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by DriVer:
I am of the opinion that all the duals (4) need to be inflated to the same pressure.
</div></BLOCKQUOTE>

My opinion also. All the tire documentation I've seen states inflate ALL tires on the same axle to the same pressure. Inflating adjacent duals differently would stress the tire with the pressure that was different than stated in the manufactures weight/pressure tables.

-Tom

[wddogger]

I just received a reply back from Michelin regarding determination of correct inflation pressure; e.g., same pressure for all tires on a given axle using the highest pressure based on "corner weight" for all tires on that axle? or each "corner" weighed independently and inflated independently according to their tables?

Here's their reply.

The best practice for obtaining proper psi is to have each corner weighed then inflate all tires on that axle at the same psi that meets the load requirements of the highest weight. In other words, all tires across the same axle should have the same psi.

I hope this helps.

Drive Safely,

[Fred and Bonnie]

Quote:

Originally Posted by wddogger I just received a reply back from Michelin regarding determination of correct inflation pressure; e.g., same pressure for all tires on a given axle using the highest pressure based on "corner weight" for all tires on that axle? or each "corner" weighed independently and inflated independently according to their tables? Here's their reply. The best practice for obtaining proper psi is to have each corner weighed then inflate all tires on that axle at the same psi that meets the load requirements of the highest weight. In other words, all tires across the same axle should have the same psi. I hope this helps. Drive Safely,

Yep, thats why you need to weigh all the corners, not just the axle.

fred

[DriVer]

Quote:

Originally Posted by wddogger The best practice for obtaining proper psi is to have each corner weighed then inflate all tires on that axle at the same psi that meets the load requirements of the highest weight. In other words, all tires across the same axle should have the same psi.

wddogger, This is the procedure that I subscribe to and I have been using this strategy over the years. I add +5psi+ to the pressure which will give me time to adjust the pressures if they are found to be at minimum. I would rather loose 5 psi and be at minimum than start at minimum for the maximum load and wind up below the recommended pressure.

[FrankO]

I don't know how one starts the day with even pressure in the rears and think that all is good during the drive. I fill my tires in the evening as temperatures dip. By morning the pressure drops significantly. This is due to a large dip in temps during the night. Morning temps at 25 or so and the pressure has dropped 6 to 9 degrees in the tires. As the sun hits one side of the MH the pressure rises quickly to even higher then I filled at night, making the inner lower than the outer. As I drive and temps rise to between 50 and 60 degress the rears will run in the low 90s and fronts will be in the high 90s. In the rear the pressure will be different between inner and outer during the drive even though I started out the day even (in the shade). When I stop for the day (let things cool down, in the shadows/shade) I check the tires and they are typically where I filled measure the previous night.
It sure helps to have the TPS system but don't think that the pressures you start the day with is what you run as conditions change during the drive.
Frank O.