Tire inflation

[dgtjhatt]

We bought a used Jayco Grayhawk 31ft. Class C E450 frame. The tires were all inflated to 80psi. The door sticker says Rears 80psi cold and the fronts 65psi cold. Wondering what tire pressure all of you with this size unit are running.
Thanks in advance for all your input.

[way2roll]

LOG wrote:

way2roll wrote:
What??

way2roll, I apologize for the confusion. In my opinion, You were absolutely CORRECT in your post. I was merely making a point that, after your post, CapriRacer suggested how to use the inflation charts and parkmanaa suggested he was incorrect. And, both posters then gave what seemed to be credentials to support their positions. I was attempting to support your post. Again, I apologize for the confusion.

ok, thanks. Sometimes I don't understand things before my coffee on a Monday morning.

[LOG]

way2roll wrote:
What??

way2roll, I apologize for the confusion. In my opinion, You were absolutely CORRECT in your post. I was merely making a point that, after your post, CapriRacer suggested how to use the inflation charts and parkmanaa suggested he was incorrect. And, both posters then gave what seemed to be credentials to support their positions. I was attempting to support your post. Again, I apologize for the confusion.

[way2roll]

LOG wrote:

way2roll wrote:

parkmanaa wrote:
DaCrema PERFECT ADVICE. Just can't figure out why more people don't do this very simple thing. By the way, that area of the Michelin website has a wealth of good general information on tires. Shame on every RVer if they don't read it.
BUT, lots of folks seem to think the RV manufacturer knows more about tires than the tire manufacturer does, so they just blindly go by that little sticker on the door post.

Agreed. The only way to know what your tires proper psi is to load your rig for travel, food, water, people etc, and get 4 corner weights or at least axle weights and use the tire manufacturers charts to adjust psi accordingly. The only way.

It seems as if the tire experts on this forum, as well as other forums, do not agree, or offer different opinions on how to use the tire manufacturers charts to adjust psi accordingly.

What??

[LOG]

way2roll wrote:

Agreed. The only way to know what your tires proper psi is to load your rig for travel, food, water, people etc, and get 4 corner weights or at least axle weights and use the tire manufacturers charts to adjust psi accordingly. The only way.

I agree. However, It seems as if the tire experts on this forum, and other forums, cannot agree on how to use the tire manufacturers charts to adjust psi accordingly. Refer to CapriRacer post above.

[parkmanaa]

CapriRacer I must take exception to the info contained in the above reply: Everything your note warns about is covered in the recommended pressure figure given for the load/PSI in the Michelin charts. (crowned highways, side-to-side differences, etc., etc., etc) If you start putting out personal recommendations you are just negating the good information provided by these charts.

5% 'RESERVE', OK if it makes you feel better.

'40 YEARS IN THE RADIAL TIRE INDUSTRY, SEEN IT ALL AND DONE MOST OF IT'

[CapriRacer]

Word of caution:

Those tire load tables are MINIMUMS!! You should use MORE pressure than the chart indicates. (I recommend 15%) That difference is called "Reserve" and vehicle manufacturers include some reserve when they specify the pressure on the door stick (called the placard).

Also, there will be side to side weight variation, so if you weigh only the axles, don't forget to include some factor to account for this. I recommend 10%, but that may be a bit pessimistic.

[way2roll]

parkmanaa wrote:
DaCrema PERFECT ADVICE. Just can't figure out why more people don't do this very simple thing. By the way, that area of the Michelin website has a wealth of good general information on tires. Shame on every RVer if they don't read it.
BUT, lots of folks seem to think the RV manufacturer knows more about tires than the tire manufacturer does, so they just blindly go by that little sticker on the door post.

Agreed. The only way to know what your tires proper psi is to load your rig for travel, food, water, people etc, and get 4 corner weights or at least axle weights and use the tire manufacturers charts to adjust psi accordingly. The only way.

[parkmanaa]

DaCrema PERFECT ADVICE. Just can't figure out why more people don't do this very simple thing. By the way, that area of the Michelin website has a wealth of good general information on tires. Shame on every RVer if they don't read it.
BUT, lots of folks seem to think the RV manufacturer knows more about tires than the tire manufacturer does, so they just blindly go by that little sticker on the door post.

[DrewE]

The door sticker is usually made assuming a fully loaded chassis (i.e. at the axle weight limit ratings). Largish class C motorhomes are usually relatively close to having the chassis fully loaded, so the door sticker pressures are usually appropriate, at least until you get specific weights for your own situation.

80 psi is the maximum for standard load range E tires that are used, and probably correct for the rear axle. 65 sounds not unreasonable for the front. If the fronts in particular are too high it can make the handling somewhat more nervous.

[DaCrema]

Get a front and rear weight at a truck stop or in some states weigh stations will give it to you for free. You need to go up to them and ask the get back in line so it is more involved. Once you know your weight go to the Michelin tire guide and look up the weight. It is ok if you do not have Michelin tires all light truck tires (load range E) have the same standard. So for example my RV has 225/75r16 load range E tires, the front axel weighs 4125 lbs, using the chart below I should inflate to 55 lbs. But I for safety I go round up one group and run 60 Lbs. I do the same for the rear axel I round up to the next group so in back I use 70 lbs. That is my truck and my weights. Your RV will be different. You should not run other people's weights. Your safe running max pressure, but it will make the RV handle funny and may ware the center of the tires early. Getting weighed at a truck stop cost only a few bucks. Then you have no worries.
https://www.michelintruck.com/reference-materials/manuals-bulletins-and-warranties/load-and-inflation-tables/#/

[wildtoad]

Not the same but, but my opinion is to use what is on the sticker. IF you find the ride not to your liking, you can get the mh weighed and adjust pressures to what the tire manufacturer says is required to handle the weight.

[mikeinaz]

Same, although I have an Entegra so they are made by Jayco.