Community Forums

jimfryar · 04-21-2014, 03:54 PM

I have a 2014 Dutch Star 4369, new to RV'ing, and trying to figure out the whole tire pressure thing. I had the coach weighed today. The weight on the front axle was 15,700 lbs. and the combination of both rear axles was 24,180. I then had them weigh both of the back axles seperately and they weighed 16,780 and 7,420. They did not have the ability to weigh each side of the coach. I have the tire pressure chart from Freightliner. Can anyone help me figure what the tire pressures should be?

GaryKD · 04-21-2014, 04:56 PM

Hi jimfryar,
Get the tire PSI chart from Michelin (assuming Michelin is on the coach. start at Michelin Americas Truck All Tires Page
The chart will tell you what the tire manufacturer says the PSI should be. Gut fee says you will have 105 PSI in the front, 90 PSI on the drive and 85 PSI on the tag.

The coach should be weighed every couple of years. Coaches are like humans they gain weight as they age. If you attend any large rallies there may be a vendor that will weigh each corner.

Skip426 · 04-21-2014, 04:56 PM

Anyone , with a tag axle who can help , will need to know , tire brand, size and weight rating. ( Load capacity on the side wall )

And I see Gary , types faster than I do. LOL.

jimfryar · 04-21-2014, 05:14 PM

288" WB-Michelin XZA1 315/80R 22.5 20-ply There are 6 aluminum, 2 steel 22.5 x 9 wheels.

Skip426 · 04-21-2014, 05:29 PM

Gary was near perfect with his gut feeling.
Web site shows, 115 psi for front weight up to 15,840
The lowest tire pressure for those tires is 85 psi, so Gary with 90 in the duals an 85 on the tag, was

jimfryar · 04-21-2014, 05:41 PM

Will it hurt to run 90 psi on all of the rear tires including the tag?

Skip426 · 04-21-2014, 05:43 PM

Quote:

Originally Posted by jimfryar

Will it hurt to run 90 psi on all of the rear tires including the tag?

No. an extra 5 psi. will not effect tire wear, probably better than running the minimum.

go oil · 04-21-2014, 07:09 PM

Jim was your coach empty?

montiem · 04-21-2014, 09:00 PM

I have basically the same coach, the sticker inside behind the drivers seat give 16000# front @125, 20000# duels @85 and 10000# tag @75#. Same size tires. Every time we discuss this the rules change, I looked on the Michelin but could not determine the exact pressures. After the last discussion I lowered my pressures to match the suggested pressures, as stated above. Also this is the first time I have time I have heard mention minimum pressures. Does the inside suggested air pressure change from year to year.

PDR John · 04-21-2014, 09:18 PM

My coach weighs almost exactly the same. The charts say:

Front: 115

Rear: all 85

I'm running the fronts at 120 and all the rears at 90

montiem · 04-22-2014, 06:46 AM

I understand, I am sure they change the pressures but my question is why. I still have the same tires,(need to buy new ones) my question is why did they change the pressure at the sames weight. On another coach I had Michelin's and the right front for some reason started wearing the on the tread in the middle, not all but the second tread from the outside. Took it to tire store and Michelin said my pressure was wrong, I had them always to the tire pressure on the placard inside the coach, finally my tire company was able to make Michelin do the right thing. To many questions and answers. I would like to know if the pressures on my placard are to low.

**TonyDi** · 04-22-2014, 07:24 AM

I run the fronts at 115 and the rears at 95 including the Tag. I feel that the tires will age out before they wear out.

PDR John · 04-22-2014, 08:03 AM

Quote:

Originally Posted by montiem

I understand, I am sure they change the pressures but my question is why. I still have the same tires,(need to buy new ones) my question is why did they change the pressure at the sames weight. On another coach I had Michelin's and the right front for some reason started wearing the on the tread in the middle, not all but the second tread from the outside. Took it to tire store and Michelin said my pressure was wrong, I had them always to the tire pressure on the placard inside the coach, finally my tire company was able to make Michelin do the right thing. To many questions and answers. I would like to know if the pressures on my placard are to low.

The pressure stated on the placard are for the weight stated on the placard, which is the gross weight of the coach.

If your running at the gross weight then that would be your pressure.

However, if you change anything from those tires and weights you air pressure needs to change as well.

A simple change in tire manufactures could require a pressure change. That's why we weigh the loaded coach and read the tire manufacture pressure charts.

TVforMyRV · 04-22-2014, 08:20 AM

Also, the tire design will have a bearing on the "correct" pressure. Each manufacturer should have a chart for the recommended tire pressure based on the model and size of the tire and the actual weight on the tire. 5% over in pressure is better than 5% under when it comes to tread wear, heat, steering, and fuel economy.