Tire weight recommended tire pressure guides

[Nasdaqsam]

Is there a standard or re these tire specific? I assume tire specific. I just bought Yokohama ZR104's size 295 80R 22.5's. I went through all the info on their web sight and can only find max cold pressure weight rating.

??????

[luvlabs]

That is the one you want.

[Mr_D]

Originally Posted by Nasdaqsam

Is there a standard or re these tire specific? I assume tire specific. I just bought Yokohama ZR104's size 295 80R 22.5's. I went through all the info on their web sight and can only find max cold pressure weight rating.

??????

Actually the charts show the minimum pressure to support that weight, not the maximum pressure.

[Mudfrog]

Not positive this is applicable to RV use but it may help. I believe it has the OP's tire size listed.

https://www.yokohamatire.com/commerc...ure-calculator

[09 harley]

Tire pressure is determined by the load on each axle. There is a recommended pressure for each tire size to be able to safely carry the weight. Does it make sense that with a completely empty coach the pressure can be lower than when the coach is loaded to the max level on each axle? Of course it does but most don't want to adjust pressures up and down as this would require. If you go with max pressure all the time just be prepared for a rougher ride when empty.

[SailorSam]

My understanding is the inflation pressures for various weights is based on industry standards. There are three organizations, one in Europe one in the US and a Japanese version. US version is at: The Tire and Rim Association, Inc.

This website has a lot of good information about tires: Barry's Tire Tech

[Nasdaqsam]

Originally Posted by Mr_D

Actually the charts show the minimum pressure to support that weight, not the maximum pressure.

This is what I can not find is a chart showing minimum. All I can fine to work off is the max pressure at cold temp. Thanks

[Nasdaqsam]

Originally Posted by 09 harley

Tire pressure is determined by the load on each axle. There is a recommended pressure for each tire size to be able to safely carry the weight. Does it make sense that with a completely empty coach the pressure can be lower than when the coach is loaded to the max level on each axle? Of course it does but most don't want to adjust pressures up and down as this would require. If you go with max pressure all the time just be prepared for a rougher ride when empty.

Right, I get that but where do I find the chart? Is that a Yokohama thing or generic one provided by others?

[Nasdaqsam]

Originally Posted by Mudfrog

Not positive this is applicable to RV use but it may help. I believe it has the OP's tire size listed.

https://www.yokohamatire.com/commerc...ure-calculator

This might be what I am looking for. Thanks

[Nasdaqsam]

Originally Posted by SailorSam

My understanding is the inflation pressures for various weights is based on industry standards. There are three organizations, one in Europe one in the US and a Japanese version. US version is at: The Tire and Rim Association, Inc.

This website has a lot of good information about tires: Barry's Tire Tech

Lots of good info thanks.

[Nasdaqsam]

Is the ride quality the only reason to run tires at less than their max cold max recommended pressure rating? Before swapping these out I have been doing a little driving on the current Good Year tires at max cold pressure it rides as good as I could ever expect.

Just trying to figure out if there is a reason that involves ruining the tire by going max or better yet what the advantage to trying to hit the perfect pressure plus a little safety margin is. But by having perfect and then adding for a "safety" margin it would seem to imply more pressure is better, no?

[Nasdaqsam]

Could this be anymore confusing? I think the more knowledge I gain the more confused I am. Especially when I talk to all the local tire shops and long haulers that just put everything at max cold pressure and leave them.

Reading the info from Barry's guide that was supplied one thing he says is the placard the manufacturer of the coach puts on it is the best bet because they are the only ones that did the engineering on the coach they built. On this one it is as follows:

GVWR is 32,800 (Does this take into account loaded?)
GAWR/Front 5,806 (12,800) 100PSI cold Single
GAWR/Rear 9,072 (20,000) 80PSI cold Dual

The tire is rated at 7,830@123 Single and 6,945@123 Dual

That is a pretty big spread from fronts 100 to 123 fronts but the rears wow 80 to 123.

When running on the Good Years it had we started with 120lbs in all 6 tires just testing some ideas I bought them down to 110 front and 105 rears. They seemed to squat more than I thought they would.

Very confused with what to do with the new tires at this point. I am going to have to get it weighed and see what I have to start with for weight. But I am 100% sure I am not over the recommended weight capacity we do not have a whole lot in coach.

[Murf2u]

Near the drivers seat there should be a placard showing what the RV manufacturer recommends based on what the coach actually weighs in their best guess-timation.

It will be way under max. PSI on the tire sidewall.

[Nasdaqsam]

Originally Posted by Murf2u

Near the drivers seat there should be a placard showing what the RV manufacturer recommends based on what the coach actually weighs in their best guess-timation.

It will be way under max. PSI on the tire sidewall.

Ok, that helps. Interestingly enough if I use the Yokohama calculator another poster gave a link to and input the weights the manufacturer gave on the placard they come out to exactly the same 100lbs front 80lbs rear. And actually I have to go all the way to 40,000 lbs in the rears to get it to recommend 85lbs so looks like 80 for the rears is spot on. Might run 105 in the fronts that covers it up to 14000lbs so a little margin.


With the placard on this coach being it was built in 2004 prior to the required loaded weight rating do I add anything or is this one the max this coach can carry even loaded?

Would anyone add a little for margin of error?