I've asked this question before...

The tire inflation tables take the anticipated increased pressure into consideration. Set your tires at the correct PSI COLD. If you've set your tire pressure based on your axle weights, your wandering problem is unrelated to PSI....Dennis

goufgators wrote:
A number of you responded a few months ago to the following question and I've tried to pull the topic back up but been unable to locate it. So, please allow me to restate the issue: Based on weights, I need to run close to 90psi. But, if I air up to 90 cold, a few miles down the hot Florida roads, psi increases to 100 to 105. At that increased psi, steering becomes difficult...wandering. Now..question...is there any reason I cannot (or should not) air up to say 80 psi cold knowing within a few miles the psi will be right where I need to be at 90 psi? I recall that when I posted earlier, some comments were pro and some con regarding doing this. I can't recall what the consensus was and would like for you to weigh in again. Thanks!

Just to clarify for you, when you figure out where your tires are supposed to be, that figure is for cold tire pressure. That means the fact that the tires will heat up and the pressure will increase is already factored in. If cold PSI is supposed to be 90, that means they want the running PSI to be at 100 or so.

et2 wrote:
Over pressure can absolutely cause bad wandering. Our MH had 115 psi in the steer tires when we picked it up from the dealer. It was like trying to wrestle a bull driving it. After a weighing and determining the psi should be set at 85, everything settled down.

So as instructed the tires were set "cold" as they're suppose to be per the weight the rig is running at.

Now ours does have a constant pull to the right which I haven't been able to get figured out. Supposedly the alignment is correct and I have new shocks and tires are set properly. I think a blue ox Tru center in in our future.

Most all roads have a crown so your right hand side is almost always downhill from your left hand side. Doesn't affect cars a lot, but can have more of an effect on motorhomes.

HERE is your other post


To find your previous posts click on 'My Forums' (top right) then click on 'my posts' (right hand side of blue header)

et2 wrote:
......Now ours does have a constant pull to the right which I haven't been able to get figured out. Supposedly the alignment is correct .......

"Set to specs" and actually aligned properly are often times two different things. Make sure you take the rig to someone who has experience in aligning front ends and not just somebody who knows how to read a computer screen. Most of today's technicians are parts swappers and not actual experienced diagnostic technicians who know how to fix things. If the computer tells them the vehicle is in specs, they don't know how to go any further. Your rig's front end might need adjusting even though the machine says it's within manufacturer's specs. A book or computer can only get you in the right area, they can't find the exact spot.

Over pressure can absolutely cause bad wandering. Our MH had 115 psi in the steer tires when we picked it up from the dealer. It was like trying to wrestle a bull driving it. After a weighing and determining the psi should be set at 85, everything settled down.

So as instructed the tires were set "cold" as they're suppose to be per the weight the rig is running at.

Now ours does have a constant pull to the right which I haven't been able to get figured out. Supposedly the alignment is correct and I have new shocks and tires are set properly. I think a blue ox Tru center in in our future.

Your wandering issues are not likely caused by over pressure,, Low pressure can do that but not over.

RV's have 3 common handling modifications and reasons for them

SWAY, this is the rig lans to one side,then the other like fans with their lit BICs at a rock concert.. SWAY BARS attempt to control this..Your RV has one but it may need an upgrade.. (mine is good).

Wag: think of a dog wagging his tail side to side.. now look at his body.. Tail wag is another matter on RV's pulling something (Trailer wag) but we are looking at the body.

Leaf spring suspension allows the body to move side to side... IF the front moves say LEFT while the rear moves RIGHT you precive you are wandering left,, So you correct, and the body swaps so now you are (in fact) moving right, so you correct.. In reality had you not corrected you'd be going straight down the road.

TRAC BARS also called pan hard bars Stop this dead in it's tracks. I used just a front Trac Bar but they tell me the rear is even better at controlling it.

Finally we have steering stablizers.. These try to encourage you to remain on the straight and narrow (Hold the steering in the center position) Mine is a Blue Ox so i can re-center from the driver's seat if the driving conditions reqauire it. I believe it is Safe-t-Steer that also offers this same feature.

When the pressure increases the tires roll easier and thus LESS steering pressure required. X2 look for other issues, worn tie rod ends idler arm, bell crank, etc. It would help also to know the year, make, and chassis of your MH.

Yes, there is a reason not to start at 80#. You WILL BE overloading the tires! And on steers to boot. Do NOT do that, if you value your life.

You have some other problem. It may seem like the 10# is causing the problem, but it is not. Never heard of 10# change in pressure causing the problem you speak of. You have another problem, which should be fixed.

Why not look for the reason your steering becomes difficult? It is NOT because of air pressure. I would guess that your front axle is loaded light or that you have worn steering/suspension components.
ALL of the tire charts say that you should set your tire pressure when the tires are cold. Running them at a lower pressure can and will eventually cause tire damage.