Tire pressure

[LinDens]

We have a Winnebago Class A, 27 ft. Vista.

The sticker on the driver wall says that GAWR front wheel weight is 6500 pounds, rear wheel weight is 11,000 pounds. Tire size 245/70R10 5G 19.5 x 6.75. Label says 82 psi.

When we got our motorhome, the tires had 105 psi and every seam in the road is quite noisy. Now these tires are rated for up to 110 psi. Is the 82 psi sufficient pressure for these tires and the weight of the coach?

Thank your for your assistance in this matter.

Linda

[willald]

..What 'Executive' said. 🙂

I went through the same ordeal with our 36' Georgetown MH. Any time I get ANY service done on the MH, they insist on blowing up all the tires to their max. rated pressure. Even had one very argumentative tire tech. tell me that you should ALWAYS inflate the tires to the max. pressure shown on sidewall, regardless how much weight is on them. Like already said, guess they have to think that way, for liability reasons. Best way is to use the charts, though, based on actual weight numbers you get at a weigh station.

Forest River says 82 psi on the placard inside on mine. I weighed the rig fully loaded, using those numbers and Goodyear's charts, determined it should be around 84-85 psi. Added 5 pounds for safety, and set them all to 90 psi. Seems to ride great that way.

[LinDens]

Thank you for all your advice.

[Cass_Sumrall]

I went through the same process with our 2013 Itasca Sunstar 30T.

It came with 90 all around. The plackard by the driver's seat says 82.

The service manager said 110.

I tried all & settled on 85 as handling best. But it depends on how your coach is loaded. Ours is well under max gross weight with two average size adults & two medium size dogs & normal load. Weighing is best but may be very inconvenient for you so you may not get around to it as I have not. I suspect you will be fine at 82-85 unless heavily loaded.

[CapriRacer]

A word of caution:

It is common nowadays for vehicle manufacturers to specify tire pressures more than the minimum. Check the GAWR's vs the placard. If you are going to use the tire load tables, do NOT forget to include this amount of over pressure - and do NOT forget that there is side to side variation.

And to address counter arguments BEFORE they are posted:

1) The tire load tables are MINIMUM's, not recommendations (even says so on the charts)

2) Tire wear is only slightly affected by inflation pressure. Other factors have much more of an affect. Besides, as time goes on, tire manufacturers will adjust (and have been adjusting) their tires so they wear evenly at elevated pressures.

[jadatis]

As long as you did not weigh , you have to do with the GAWR's.
Then add 5% to the front , because front is seldomly overloaded.
Add 18% to rear GAWR, because back is often overloaded.
Look at the sises of your tires, you give
245/70R10 5G 19.5 x 6.75., I asume its 245/70 R 19.5 and the 10 5G got between it because the computer was thinking to be clever.
So I googled that sise , and because I live in Holland, first an Eng/austr page came up with the better calculation.
The english page with better calculation
top of 2nd page your tire-sises. and as is usual in Europe no different loadratings in one list and a reasonably save calculation for loadcapacity at lower pressure.
Also notice the second loadindexes for speed L =120km/h wich is 1 LI higher. For 130km/80m/h its 135/133M wich I filled in my motorhome tire-pressure calculator .
Here a picture, mind that the American tire date can be a bit diferent , you can find maximum load single and dual on the sidewall.
Mayby also a second loadindex for lower speed.


In next map on my skydrive you can download the spreadsheet with your username by RIGHTCLICKNG and then choose download, and you can fill in the weighed loads once you have them , to see if it gives other advices.
If you also give the GVWR the spreadsheet also gives information if the vehicle is overloaded .
The examples map with LinDens calculator

Your tires are a bit oversised and the original where probably F load with lower maximum load. Then the rimms probably also for lower pressure rated , mayby even 80 psi. So try to look this up.
It might be that your tires may have that 105 psi ( even 10 psi more) but the rimms may not. This would be an extra reason , not to go over the advices on the rig.

[J-Rooster]

Gale Hawkins wrote:
As long as a shop airs them to max they are in the clear of sending out under inflated tires. 🙂

X-2, I run 100 psi all around!

[Gale_Hawkins]

As long as a shop airs them to max they are in the clear of sending out under inflated tires. 🙂

[Go_Dawgs1]

All that Executive is true and you will probably come back with it saying to be at 82psi. But with that said go a weigh the rig, I did, and set the pressure to the chart.

[Executive45]

The tires are inflated to max pressure when you received it because it's not loaded etc. so they inflate them to sidewall pressure. That said, it's probably not what you need although it may be. The GAWR ratings are max load weights also. Here's what you do to be safe:

Load your coach as you would if you were going away.
Stop by a Flying J/Pilot, truck stop, moving company etc. and have your coach weighed...each axle. Individual wheel weights are optimal, but few scales have that ability. The weight ticket will be about $10.
Go to your tire mfg website and look for your axle weights.
Use that table to determine the proper PSI for your tires.

If you have any difficulties, return here and post your tire mfg and weights and we will help you. Be safe and enjoy...Dennis