Tire Pressure

[Mirada2005]

Hi All - we have a 2005 Class A on a Ford F53 chassis. The general weight of the coach is 14,680 pounds. Yes we have had it weighted.
What are folks running for tire pressure? We do not carry a lot of "stuff", so we probably are pretty light by most standards.
100 PSI is the number I see most often.

Any info is appreciated.

Les
T.O. CA

[Suburbazine]

Originally Posted by Mirada2005

Hi All - we have a 2005 Class A on a Ford F53 chassis. The general weight of the coach is 14,680 pounds. Yes we have had it weighted.
What are folks running for tire pressure? We do not carry a lot of "stuff", so we probably are pretty light by most standards.
100 PSI is the number I see most often.

Any info is appreciated.

Les
T.O. CA

The number (minimum cold pressure) is determined by the tire manufacturer's weight charts, not a generic value like a door sticker or another owner's preferences. You'll need to know your per-axle weight like you would get from a CAT scale.

[Mirada2005]

Originally Posted by Suburbazine

The number (minimum cold pressure) is determined by the tire manufacturer's weight charts, not a generic value like a door sticker or another owner's preferences. You'll need to know your per-axle weight like you would get from a CAT scale.

I have the axle weights - now I need to find the tire manufacturer weight charts.

[BillJinOR]

Go to the tire manufacturer web site most have them listed somewhere there. You don’t list what tires you have

[jadatis]

You can also use my made lists, in this map on my onedrive that belongs to my hotmail adres with username jadatis

https://1drv.ms/f/s!AtzmkuDu4Calhy1JOdG0mFbnyEF9

You cann choose given per axle or per tire, single and dual, yust what is most handy for you.

Made with an extra safe formula that leads to higher pressure for the load, or lower loadcapacity for the pressure, then the officiall used, wich this " pigheaded Dutch selfdeclared tyrepressure-specialist " got hold of end 2007 and went running with.

But you can also give the tirespecifications here, and I will put it in my made calculator.
Need , 1.maxload or loadindex single/ dual.
2. Kind of tire, loadrange or better pressure behind AT written on sidewall. Speedcode and sises would be nice to.

And of cource the axleweights, and what you expect comes extra in weight, and configuration( number of axles and if duallload axle).

If you rather use an officiall list, or my made lists, first add 10% for reserve to the determined weigt ( so incusiv extra like persons first added) , and look up that weight in the list.

I realise you better trust the official lists above that made by an European amateur self declared specialist, but even the official lists in europe lead to lower loadcapacity's then those of US. My calculation even lower loadcapacity' s then the European, so always saver.

[swampdog2]

Or you could take the max weight stamped on the tire and devide it by the max pressure stamped on the tire and that will give you weight per lb of pres ! Example : 2600 lbs at 80 psi ( 2600 -:- 80 =32.50 lbs per 1lb of air ! So 65 x32.50 =2112.5 lbs ! That's what the tirexwould hold weight wise with 65 lbs of air !! Hope this helps make it simple !

[jadatis]

That is not even a bad calculation, my calc comes close to it.
If you want a reasonable simle calculation that comes closer to the way the tiremakers make the list, you can do next, a bit more complicated, but still to be done.

First add the 10% reserve to the weighed axleloads in the loading you use ( so not empty)
Then devide by the number of tires on the axle.
Substract 100lbs of that ( assumed by me loadcapacity at zero pressure) from determined tireweight and maxload of tire.
Then do the lineair calculation as you do.

Your lineair calculation assumes zero loadcapacity at zero pressure.