Tire Pressure?

jadatis wrote:

turbojimmy wrote:
Ok. Tire markings say max loads are 3305 used as a dual, 3525 as a single at 110 PSI. So I have a lot of headroom there. Tire type is 124\122M 12PR\LRF which seems to mean it can be used as either a truck or trailer tire.

I think I'll inflate them to the axle max, not the 110 PSI. 110 PSI seems like overkill. So I'd be inflating to 2000 lbs in the front (4000÷ 2) and 1600 in the back (6400÷4). That is until I can get it properly weighed.

whats on the tire 12pr/LRF and given AT-pressure of 110 psi dont match For this description it should be 95 psi, but there are exeptions in that system.
Can be that they are special camper tires C/CP and for those Michelin gives only maximum pressure and not AT-pressure.
So look again if in front of 110 is written "max pressure"or "AT"
Not even sertain so I will go from the maximum loads given AT 110 psi in my made spreadsheet.

Have made a map in the examples map on my one drive public map with your username turbojimmy.
You can download it to your computer or open it to look in.
https://onedrive.live.com/?cid=A526E0EEE092E6DC&id=a526e0eee092e6dc%21836

And here a picture made of it and gives Front 62 and rear 59 psi advice . When AT pressure apears to be 95 later advice will be lower even.
But also lowered the Loadindexes by 4 to get deflection of tire that belongs to 99m/h and this gives highest to fill advice , higher gives bumping and gives Front 71 and rear 67 psi advice pressure .
With these advices enaugh reserve for overloading and unequall loading, read the information below the pressure advices.

Sorry I cant include a picture because those St*&^%d American One drive that belongs to Hotmail have chanched the system again so have to find out how to do it again.
But open the map and you will see it

Huh??? :h

turbojimmy wrote:
Ok. Tire markings say max loads are 3305 used as a dual, 3525 as a single at 110 PSI. So I have a lot of headroom there. Tire type is 124\122M 12PR\LRF which seems to mean it can be used as either a truck or trailer tire.

I think I'll inflate them to the axle max, not the 110 PSI. 110 PSI seems like overkill. So I'd be inflating to 2000 lbs in the front (4000÷ 2) and 1600 in the back (6400÷4). That is until I can get it properly weighed.

whats on the tire 12pr/LRF and given AT-pressure of 110 psi dont match For this description it should be 95 psi, but there are exeptions in that system.
Can be that they are special camper tires C/CP and for those Michelin gives only maximum pressure and not AT-pressure.
So look again if in front of 110 is written "max pressure"or "AT"
Not even sertain so I will go from the maximum loads given AT 110 psi in my made spreadsheet.

Have made a map in the examples map on my one drive public map with your username turbojimmy.
You can download it to your computer or open it to look in.
https://onedrive.live.com/?cid=A526E0EEE092E6DC&id=a526e0eee092e6dc%21836

And here a picture made of it and gives Front 62 and rear 59 psi advice . When AT pressure apears to be 95 later advice will be lower even.
But also lowered the Loadindexes by 4 to get deflection of tire that belongs to 99m/h and this gives highest to fill advice , higher gives bumping and gives Front 71 and rear 67 psi advice pressure .
With these advices enaugh reserve for overloading and unequall loading, read the information below the pressure advices.

Sorry I cant include a picture because those St*&^%d American One drive that belongs to Hotmail have chanched the system again so have to find out how to do it again.
But open the map and you will see it

turbojimmy wrote:
I think I'll inflate them to the axle max,,, That is until I can get it properly weighed.

Axle max is probably OK as long as you are not overloaded. Axle max is what I use but I check my weight at the beginning of my camping season to set my base line and first stop when I head out on a long adventure when I usually have two weeks' worth of stuff crammed into the coach. Also at my normal weight I'm off the bottom of the inflation charts. Got more load capability in the tires than what the axles can safely carry. $10 at a CAT Scale will give you good general numbers to work with but if you can find a place to get each wheel checked even better.

For that warm fuzzy feeling add an extra 5 PSI which will give a bigger margin for error. I did inflate to sidewall listed max once. Lane wander was pretty bad and the ride was very harsh.

turbojimmy wrote:
Ok. Tire markings say max loads are 3305 used as a dual, 3525 as a single at 110 PSI. So I have a lot of headroom there. Tire type is 124\122M 12PR\LRF which seems to mean it can be used as either a truck or trailer tire.

I think I'll inflate them to the axle max, not the 110 PSI. 110 PSI seems like overkill. So I'd be inflating to 2000 lbs in the front (4000÷ 2) and 1600 in the back (6400÷4). That is until I can get it properly weighed.

I would go with axle weight and then add another 5-10 pounds just to allow for any leakage until you get the coach weighed. Remember to get it weighed with full fuel, all normal passengers, and as much fresh and waste water that you plan to carry when loaded for a long trip, in addition to food, clothing, tools, etc.

Ok. Tire markings say max loads are 3305 used as a dual, 3525 as a single at 110 PSI. So I have a lot of headroom there. Tire type is 124\122M 12PR\LRF which seems to mean it can be used as either a truck or trailer tire.

I think I'll inflate them to the axle max, not the 110 PSI. 110 PSI seems like overkill. So I'd be inflating to 2000 lbs in the front (4000÷ 2) and 1600 in the back (6400÷4). That is until I can get it properly weighed.

Thanks for all the replies. It seems like I should get it weighed, but also see what sort of 8R19.5 tires I have. I got them at a truck tire place, and told them what it was for. Hopefully they're correct. I'll check the sidewalls to see what they say.

Ok, I'll take a stab at this.... see my comment in red.

But my post has 3 parts.

1 is to get the exact tires and kind of vehicle right.Ok, this makes sense.

2 is the part you dont understand about the universal used formula What...universal formula? all over the world wich has a power in it(What power are you talking about? and what is it applied to? , and the different powers used in American and European system, and that to laws of nature this should be one power This doesn't make any sense to me at all.. This power formula was introduced in 1928 for diagonal tires what are diagonal tires?with power 0,585 power 0,585???and was meanth meanth? for the tire-fitter to use a simple formula to determine needed pressure, but totally missed its goal because almost nobody understands the power part in it. Europe chached chached?the power for radial tires to 0.8 for all kind of radial tires about 1970 and America to different powers of 0.5, 0.65, 0.7 and as late as 2006 chanched the 0.5 and 0.65 for P-tires and XL to that of Europe of 0.8. For C-load and up ( LT and truck tires) America still uses 0.7 power.
This all to calculate loadcapacity for a pressure.

3th part is the copy what copy? where is it? how is it applicable to this subject? of text I used in other topic what other topic? to show wich data are needed from tires and vehicle before we can calculate.

Again...no disrespect, but your post leaves a lot to be desired.

Ron

lanerd wrote:
I apologize for my rude remark...it was uncalled for. I understand you're providing the best info you can, but your explanation is difficult to read and comprehend. I hope others have understood better than I.

Ron

I think the American expression is "no offence taken"
I get these kind of remarks more often .
But my post has 3 parts.

1 is to get the exact tires and kind of vehicle right.

2 is the part you dont understand about the universal used formula all over the world wich has a power in it, and the different powers used in American and European system, and that to laws of nature this should be one power. This power formula was introduced in 1928 for diagonal tires with power 0,585 and was meanth for the tire-fitter to use a simple formula to determine needed pressure, but totally missed its goal because almost nobody understands the power part in it. Europe chached the power for radial tires to 0.8 for all kind of radial tires about 1970 and America to different powers of 0.5, 0.65, 0.7 and as late as 2006 chanched the 0.5 and 0.65 for P-tires and XL to that of Europe of 0.8. For C-load and up ( LT and truck tires) America still uses 0.7 power.
This all to calculate loadcapacity for a pressure.

3th part is the copy of text I used in other topic to show wich data are needed from tires and vehicle before we can calculate.

Until you weigh your vehicle, you should inflate your tires to the pressure on the sidewall which assumes that you are carrying the maximum amount of weight that the tires are designed to carry. Remember, the pressure on the sidewall is the MINIMUM psi for the maximum weight carrying capacity of the tires.

I apologize for my rude remark...it was uncalled for. I understand you're providing the best info you can, but your explanation is difficult to read and comprehend. I hope others have understood better than I.

Ron