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Burker99 · 02-13-2019, 07:15 PM

Hello Everyone,

I have a 2001 Monaco Night 36’ DP. My question is about tire pressure. The tires are Goodyear G 661 HAS load range H 255/70 R 22.5 The tires say max. pressure 120#

I am not sure what the correct pressure should be. I have not weighed the RV but I have a Cat Scale ticket from the previous owner. He weighted it ready to travel. Full fuel gear and water.

The ticket shows a total of 27,140# but 3120# of that is his toad. The front weight was 8640#. The rear was 15,380#. If I understand this right that means each front tire has 4320# on each. The rears (duallys) have 3845# on each of the four tires.

The sticker in the coach says to inflate front and rears to 80#. I have looked for an inflation chart on the internet for these tires and have not found an exact match. I have found very similar Goodyear's that say
The rears should be at 80# and the front at 85#. When I checked the tires, they are at 90#.

I would like to lower the pressure a little to help with handling. The RV has the steering box that is not adjustable and has some play in the wheel and wonders a bit at high way speed 60-65 mph.

Any insight on correct pressure or where I can find a chart is appreciated.

Thanks as always,
Lurker

windsorbill · 02-13-2019, 08:46 PM

Goodyear makes a HSA tire, you listed a HAS .
Not sure if that's a typo or not.

https://www.goodyeartrucktires.com/p...t_oct_2015.pdf

If I were you, I'd re-weigh the coach with your gear in it. You really don't know how the PO had it loaded. It's best if you can weigh each corner, not just the front/rear axle. In your example, you took the front axle weight and divided by 2 and the rear axle and divided by 4. You're assuming the coach is equal weight, left and right. My coach is nearly 1400# difference from left/right. Once you do that, then use the heaviest side to calculate all tire pressures for that axle.

veraken · 02-14-2019, 05:12 PM

The tire pressure on the side of the tire is the maximum tire pressure when carrying the maximum weight. To determine what the right tire pressure is for you, you need to weigh your MH. Load your MH as you would for travel, fill you gas and water tanks and then get your MH weighed.

If you can't do 4 corner weighing (which is the preferred method), this is the procedure to follow:

1. Weigh the coach axles
2. Add 5% to account for possible uneven weight side to side.
3. Divide by the number of tires on each axle.
4. Look to the tire chart for your brand to find tire pressure.
5. Add 5 psi for safety

K7JV · 02-15-2019, 06:21 AM

And don't overthink it. A few PSI away from the recommended pressure is not a big deal. After all, once you start rolling on a drive, depending on outside air temperatures, your pressures can easily go up 5 to 10 PSI.

The posts above are giving you good advice on finding the right pressures. Also, be sure to look at the side of your tire and see if it has a "minimum inflation" value. I would try not to go under that pressure.

Also, when you see outside temperature changes or climate changes from moving north/south or high/low, your tire pressures will change.

I have a good quality tire monitor system on our coach, and I check the pressures pretty regularly on it. And I rarely add or take away air to "hit the numbers". I have a great deal of comfort believing that I will be warned well in advance if I have a coach tire or a toad tire that starts losing air on the road, and can probably/hopefully do something about it before it fails. If one does suddenly fail, I know immediately and can at least minimize the damage.

zo66 · 02-20-2019, 11:46 AM

Lurker,

You probably already know this, but be sure to check the date code on the sidewall to verify the age of each tire.

The manufacture dates can vary greatly from tire to tire, even though the tires may have been installed at the same time. When I replaced my original set, the local tire shop ordered (6) new Michelin's for me. I was warned to visually inspect each tire before they mounted them. Glad I did. All of the tires were only a month old, except one, that was a year and a half old! Needless to say I had to make another trip back to the tire store a week later when the last fresh tire arrived. These tires are way too expensive to pay for tires that are partially aged out.

I didn't know how important it was until someone pointed it out to me.

Jim