Tire pressures for Canyon Star 3920? Tire Minder question!!!

[Iggyval]

Hi Everyone:
I have a 2012 Newmar Canyon Star 3920 (Toyhauler). I'm just setting up my Tire Minder. Does anyone know what the tire pressures are supposed to be. Are they more for the steering tires and less for the dual tires in the back? I think the PSI is 110 (that what they say on the tire). Do you all have different pressures for the dualies in the back? Please let me know!!! Thanks so much!!!

[Mr_D]

In order to set the correct pressure for your rig you will need to load it for travel, including passengers and weigh all four "corners", then check the weight/pressure charts for your brand/model/ply rating of your tires.

The pressure on the sidewall of a Michelin RV tire and many others is not the "Maximum" the tire should ever have (unlike car tires) it is the minimum to support the maximum rated carrying capacity of the tire.

From the Michelin RV Tire Guide:

"If you look at the tire's sidewall, you'll see the maximum load capacity allowed for the size tire and load rating, and the minimum cold air inflation needed to carry the maximum load."

From page 6 of the GoodYear RV Tire and Care Guide:

"How much air is enough?
The proper air inflation for your tires depends on how much your fully loaded RV or trailer weighs. Look at the sidewall of your RV tire and you’ll see the maximum load capacity for the tire size and load rating, as well as the minimum cold air inflation, needed to carry that maximum load."

From TOYO:

Q: What are the consequences of inflating the tires to accommodate the actual loads?
A: If the inflation pressure corresponds to the actual tire load according to the tire manufacturer’s load and pressure table, the tire will be running at 100% of its rated load at that pressure. This practice may not provide sufficient safety margin. Any air pressure loss below the minimum required to carry the load can result in eventual tire failure.

But then they go ahead and publish a weight/pressure chart allowing lower pressure for RV's!!

From the August 2010 Motorhome Magazine "Tread Carefully" tire article:

The maximum load capacity allowed for the size tire and load rating and the minimum cold air inflation needed to carry that maximum load are located on the tire’s sidewall.

From our owners manual:

Federal law requires that the tire’s maximum load rating be molded into the sidewall of the tire.
If you look there, you will see the maximum load allowed and the cold air inflation pressure required to carry that stated maximum load. Less air pressure restricts the tire to carry a lighter load.

[fly_1]

Unless you have actual corner weights you should use the pressure listed on the tire pressure plate. The tire pressure sticker/plate should be located behind your driver's seat on the wall. That sticker will also tell you the tire size, GVWR and axle weight ratings.

For high and low alarms I suggest:

1. 5% below the tire listed pressure for your low pressure alarm.
2. 20% above that pressure for the high pressure alarm.

Once you get your corner weights you will use the heaviest tire or duel set to determine the pressure for all tires on that axle.

Typically a gasser will run higher pressure on the rear tires than on the front ones.