Tire Pressure

augustpilot wrote:
Goodyear sheet calls for 85psi cold, rambler manual calls for 90psi. First owner carried 100psi.

I wouldn't go below 90 psi cold pressure. The builder recommended pressure is if you have the coach loaded to maximum axle limits and the tires installed are the same size and load range as originally equipped. I suspect you are not quite there but add a few more people and associated stuff and you could be. Won't hurt going to 100 either. Try both to see how the coach rides but I would never go below 90 psi cold pressure.

Googled your tires and in the same sise I even found J-load from wich I dont know wich yyy belongs to that, but on goodyear site found 125psi and maximum load single of 6940 dual 6395 wich is loadindex 148/145.
with yyy ( wich is called the reference pressure Pr and is not the maximum pressure). Filled this in with the loads you gave and assumed behind to be dual , because otherwise 2 tires cant carry the axle load.
Here the picture , beneath the presssure advices of 93/96psi with 5% loadreserve, wich is not exagerated , aditional information about weightdivision and used percentage of the tire maximum load etc.
So the 100 psi all around is ok and I played with the reserve to find 12% reserve front and 9 % reserve rear at 100psi wich is still ok and wont give bumping still , concluded that to happen under 85% L% given in the spreadsheet wich is the same as adding 18% , but discussable I know.

The pdf and Excel xls file is also in the examples map on my skydrive that belongs to my hotmail adress.
examples map in the map of the calculator
So if you find the GAWR's you can add them and you get more aditional information about the axles. If the tires apear to be different you can chanche that too in the spreadsheet.

I am about the same weight with the same tire. I run 115 in the front110 in the rear. On my second set and neve a problem. Always allow 10% over what you need.

There is a sticker behind the drivers seat just under the hooks for the windshield drapes that tells me to carry 110 in the steers and 100 in the rear tires.
This seems to be right for my 2004 Endeavor.

Mike

The RV manufacturers seem to always show a lower PSI then you'd expect from the actual loaded weight. Most of us think that is to give a more cushy ride as you drive off the dealers lot, they don't care about tire life.

The rule is to weigh your rig, check the tire manufacturers web site for pressures needed for that weight. Plus 5-10% to improve tire life. It's quite possible that the previous owner kept the pressures at 100PSI because he'd had experience with tires wearing out to quickly because of low pressure.

What I need before I can trow the data in my motorhome-tirepressure calculator is the yyy in "maximum load xxxx lbs AT yyy psi(cold) "and also the xxxx or the loadindex written on sidewall.
A stiffer tire, say a G-load with yyy=110psi needs for instance a higher pressure for the same load then a E-load tire with yyy=80 psi.
If you can give that, and throw also the GAWR's in when you are busy, then I will produce advice pressures and show a picture of the calculator in my answering post

He said he had it weighed so not just ratings. However, I'd go with what Goodyear said. I suspect the manual is based on what the original tire specs stated based on the GAWR. Being that the difference is only 5lbs, either one will do.

My discovery has about the same axle weights loaded. I inflate to 90psi cold on the same size tires. This gives about a 5% safety margin yet provides a good ride.

May be some confusion here. Are 19k and 10k the GAWR's or actual weights as measure with coach loaded as you travel?

It depends on your rigs weight. I've never seen a chart that doesn't require the loaded weight of your RV to tell you how much pressure the tires should have.

Hhg