Community Forums

Jtrving · 03-22-2018, 08:30 PM

So I have done exhaustive research on correct tire pressures and the reality is I probably won't be able to get my 4 corners weighed for a while and I have a big trip coming up in a few weeks and want to know where to set my tire pressures.

1) Do I just inflate to the pressure on the sticker provided by Spartan knowing they are inflated more than need be, accept a little rougher ride and a little compromise in fuel economy and be done with it?

2) I do have my corner weights from when the coach left the factory which I confirmed is with 1/2 tank of fuel and no fresh water. I would estimate that worst case scenario - with full tanks, the two of us, dogs, and equipment and supplies we add another 4K lbs, how is that distributed to the three axles? If I add 2K to the front and drive axles (none to tag), the Michelin tire chart puts me at between 110-115lbs on the fronts, and even at 10K on the drive, the chart doesn't even start until 11680 which would be 85lbs, and even if I add an additional 1K to the tag it doesn't even get me to 85 there either.

So should I just run 115 in the front and 85 on drive and tag?

ghaynes754 · 03-22-2018, 08:34 PM

On my 4369 I run 110/85. So your numbers seem to be on target.

Jtrving · 03-22-2018, 08:36 PM

315's or 365's on front?

Buly · 03-22-2018, 08:44 PM

On my DS 4369 I also run 110 front and 85 rears.

GreaTOne65 · 03-22-2018, 08:52 PM

I don't believe any tire should be run lower than what is stamped on the tire. But that's me. I run 120 lbs. in all of my tires, you will never have a problem with the Max pressure on the tire.

Mr_D · 03-22-2018, 09:06 PM

Pressure on the sidewall of an RV tire is NOT the maximum, it is the MINIMUM to support the maximum weight rating of the tire.

Mark71 · 03-23-2018, 05:44 AM

Corner weights are hard. Axle weights not so much. Why don't you get axle weights, refer to the Michelin guide and run THOSE pressures for the indicated weight? Or are you saying it's hard for you to get AXLE weights?

Jtrving · 03-23-2018, 05:46 AM

Quote:

Originally Posted by Mark71

Corner weights are hard. Axle weights not so much. Why don't you get axle weights, refer to the Michelin guide and run THOSE pressures for the indicated weight? Or are you saying it's hard for you to get AXLE weights?

I will eventually get to that, but just asking what people would do if they didn’t have updated weights after delivery and with full tanks and gear. Looking like 115 and 85 will be fine for now.

Podivin · 03-23-2018, 06:02 AM

Quote:

Originally Posted by Jtrving

I will eventually get to that, but just asking what people would do if they didn’t have updated weights after delivery and with full tanks and gear. Looking like 115 and 85 will be fine for now.

What I did on mine was set the tire pressure to what is specified on the yellow sticker which should be found next to the driver's seat.

After I got the MH weighed I set the tire pressure based on the mfg's weight chart - which in my case exactly matched the sticker on the wall.

BigBillSD · 03-23-2018, 09:19 AM

Cat Scales seem to be everywhere and for about $10 will give you your axle weights. Using your factory weights you should be able to estimate the weight distribution close enough till you get corner weights done. I just finished a camp freightliner class and the instructor who was a long time in the business suggested you add 5 lbs to the fronts and 10 to the rear, over the tire charts inflation. It makes sense after my experience this week. The evening before I left for Tucson this week I put all my pressures at the exact setting for my weight. Fronts 110/90 for the rears. In the morning all were 2 lbs low... because the tires were much cooler in the morning. The instructor told me that I drove here on underinflated tires and suggested we all fill our tires in the morning prior to the sun hitting them.. I think I will just use the +5 in the fronts and +10 in the rears just so I don't have to air up my tires at O Dark Thirty. ..

-Bill

aether_one · 03-23-2018, 09:33 AM

Quote:

Originally Posted by GreaTOne65

I don't believe any tire should be run lower than what is stamped on the tire. But that's me. I run 120 lbs. in all of my tires, you will never have a problem with the Max pressure on the tire.

Quote:

Originally Posted by Mr_D

Pressure on the sidewall of an RV tire is NOT the maximum, it is the MINIMUM to support the maximum weight rating of the tire.

No, the pressure on the sidewall is the maximum cold inflation pressure:

See the word "MAX"?

Don't see the word "MIN:.

"007" · 03-23-2018, 11:22 AM

Quote:

Originally Posted by GreaTOne65

I don't believe any tire should be run lower than what is stamped on the tire. But that's me. I run 120 lbs. in all of my tires, you will never have a problem with the Max pressure on the tire.

Your label on wall near drivers seat will have the pressure needed for your load of your RV.
Also using the MAX sidewall tire pressure you can add to your hard ride another 15 to 20 psi as your tires heat up.
You can get a better ride by using proper tire pressure.

GaryKD · 03-23-2018, 01:51 PM

Hi Jtrving,
You should be fine with what you said in post #8.

blackhawkscp · 03-23-2018, 05:35 PM

I had a similar problem last year. I set mine to the yellow sticker inside. I had a service get me to the 130 front axel and 120 rear. I was killing myself trying and I wanted to be right per the sticker. He thought they were very high. I went nuts trying to figure out what I should be at as I hadn’t weighed the coach yet. I finally got numbers from Newmar as it left the factory and compared to the Michelin chart. I was way too high even with some assumptions I made on added weight for personal stuff etc.. I finally got actual axel weights (not corner) and I added 500 pounds to both (since I didn’t know the corner weights for sure). I ended up setting my front at 115 and rear at 90. Way off from the yellow chart. Do yourself a favor and weigh it as soon as you can fully loaded and then adjust accordingly. I went to Pilot. Wishing the best in your travels.