Community Forums

offthewall · 01-08-2011, 05:52 PM

Just curious what those who have had their Itasca Meridian V Class 34Y (Winnebago Journey Express 34Y) weighed at full load are actually running for front and rear tire pressures with the stock Michelin XRV 255/80 22.5 tires?

Even at the max GVWR, according to the Michelin charts, it seems that you should only be running 95psi in the rears compared to 110 as printed on the door frame sticker.

Ours is brand new and hasn't been loaded yet let alone weighed.

Again, it's just curiosity as to weather you wind up running less pressure in the rears than the fronts.

TIA

GaryKD · 01-08-2011, 06:03 PM

Hi offthewall,
Consider posting this question in the Winnebago Owners forum. Nobody knows your coach like somebody who owns one just like yours.

Generally speaking, the 15 PSI difference from front to rear is about right. For the size tire mentioned, Michelin does not like anything less than 85 PSI in the rear tires. This means you are not far from Michelin's minimum recommend PSI for the rear tires, regardless of how light the coach is.

Fred and Bonnie · 01-08-2011, 09:36 PM

I think you will find the tire pressurers listed on the Winnie sticker are the pressurers if the axle was loaded to the max weight.

fred

Meurigd · 01-08-2011, 10:14 PM

I have an '07 Meridian 36G with the same Michelin tires as you. For the first 25,000 miles or so I ran 100 psi in all tires, regardless of loads and never had a problem. Tires looked like new. Then I went to a tire seminar at a rally where I obtained the Load / pressure tables that Michelin publishes. So I then adjusted my tire pressures (down) to correspond with my weighings. I think I carried 90 psi in the rears, 85 psi fronts, to correspond with my weights. Then sometime after that, I am not sure how many thousands of miles, I noticed some slight flat spots, appearing on the outer circumference edges of both front tires. After visits to my local Freightliner dealer and Les Schwab, and some discussion on the Winnebago board, I concluded that my problem was "Shoulder Step Chamfer wear", which in the opinion of some, can be attributed to under inflation. (But is also sometimes described as "normal wear"). Go figure. Any way, I immediately took my pressures back up to 100psi all round. I now have almost 35,000 miles on them and the flat spots have not gotten worse. Consequently I never run less than 100psi in my tires.
You will do what you feel comfortable doing, but this information may be a data point for you. Good luck.
Meurig Davies '07 Meridian 36G

offthewall · 01-08-2011, 11:31 PM

Quote:

Originally Posted by Fred and Bonnie

I think you will find the tire pressurers listed on the Winnie sticker are the pressurers if the axle was loaded to the max weight.

fred

I think if you re-read my original post, you will see that the Michelin pressure for the Max rear load is lower than that on the Winnie sticker.

GAWR - Rear (lbs.) 17,500 - Winnebago recd. rear pressure 110.

17640 lbs - Michelin recd. dual pressure 95.

So, following what is the conventional wisdom and Michelin's recd. I should run 95 rather than 110 in the rears at max load and probably even lower when I actually get weighed.

The Winnebago recd. pressure of 110 for the fronts in right on the money for max load according to the Michelin charts. So I wonder how Winnebago came up with the rear recd. pressures?

RV Wizard · 01-09-2011, 03:02 AM

Be sure to check the tire data tag in the coach for the proper size tires that are to be installed on the coach. Otherwise you will be comparing apples to oranges. I am not saying that your tires are the wrong ones but sometimes it does happen, especially if they are changed. It has happened in the past that the manufacturers get the wrong data for the tires they actually use and have to perform a recall that may deem a new data tag and/or tires changed out. I would suggest you call Winnebago and inquire as to the discrepancy if the tires match the data tag.

Pusherman · 01-09-2011, 06:22 PM

When I took delivery of my Journey 34H in Nov '06 the handling was TERRIBLE. After a couple trips to the dealer, and 1 trip to a trusted alignment shop, I found that 1) the alignment was spot-on, 2) my 2 front tires were out of round. I had the tires replaced. I then weighed my coach fully loaded, and adjusted down my tire pressure to 90 psi per Michelin's specs based on the actual axle weights.

I found that Winnie/or the delivery driver sets the tire pressure to the max of 110 psi from the factory, as they don't know how the coach will be loaded (my guess).

I loaded it up, had it weighed, reset the tire pressures per Michelin's specs, and I found this was the one most single item which impacted the handling of my coach.

Weigh your coach and set your tire pressures based on actual axle weights based on your tire manufacturer's recommendations (+5psi).

f14av8r · 02-28-2012, 06:02 PM

I run 95 PSI in the front and 105 in the rear duals. I add 200 pounds to the scale weight as a safety margin then pull the inflation pressure straight off the michelin charts for my individual wheel weights. You always run the same pressure on all the tires on the same axle. The coach was delivered with the tires inflated to 110 PSI and it did not ride well. Once I got it weighed and the tire pressure set properly it rides like a dream.

Mr_D · 02-28-2012, 06:19 PM

Quote:

Originally Posted by Fred and Bonnie

I think you will find the tire pressurers listed on the Winnie sticker are the pressurers if the axle was loaded to the max weight.

fred

But it also might be just the max weight the tires can carry also, it just depends on what is the lowest rated component.

Mr_D · 02-28-2012, 06:22 PM

Quote:

Originally Posted by offthewall

I think if you re-read my original post, you will see that the Michelin pressure for the Max rear load is lower than that on the Winnie sticker.

GAWR - Rear (lbs.) 17,500 - Winnebago recd. rear pressure 110.

17640 lbs - Michelin recd. dual pressure 95.

So, following what is the conventional wisdom and Michelin's recd. I should run 95 rather than 110 in the rears at max load and probably even lower when I actually get weighed.

The Winnebago recd. pressure of 110 for the fronts in right on the money for max load according to the Michelin charts. So I wonder how Winnebago came up with the rear recd. pressures?

Michelin has revised it's weight/pressure charts over the years so that may have a bearing too.