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Re: Tire Pressure

Reply #100 –
Yahoo Message Number: 1933
Hi David,

Doug Rutherford, CC, recommends 85 psi minimum, regardless of the Toyo chart numbers. Below 85, side wobble can happen resulting in lose of control, also side wall strength becomes diminished. 120 front and 110 rear is the max pressures that CC delivers the coach with for liability purposes. If you read the words with the Toyo charts, it says weigh the four locations per one of their 2 methods with the coach loaded. And understand what loaded means.
Fred Kovol

Re: Tire Pressure

Reply #101 –
Yahoo Message Number: 1939
I run with 95 psi in all tires. Tables would permit like 85 psi but I want to get the cooler tire that 95 psi results in. I have SmarTire and look at temperatures as well as pressures. The ride is not excessively harsh.

Sincerely

George W Becker

Re: Tire Pressure

Reply #102 –
Yahoo Message Number: 1942
Dave, I think the problem is that we are all trying to make this way too hard rather than just reading what Toyo recommends and following their instructions. Their tables are quite clear, imo, but we all have our own experiences and the experiences of others that we bring to the table. I think that is what causes the problem. We just don't trust the information we have. Why do I run a few pound more than what the Toyo table recommends? I think it is my belief that I am being a little more cautious if I run a margin of safety pressure up to the maximum cold pressure. I don't think any reduced pressure would make the ride any better over rough roads like the ones encountered on many interstate highways. The only thing that helps with that is to slow down to an unbearably slow speed. I think I will continue to run my tires with a pressure close to the maximum cold pressure as stated on the tires, at least with that if I load a few extra pounds in the vehicle..i.e. when I take on a few passengers or throw in some heavy item I just purchased then I feel I am covered.

I definitely would not feel comfortable running anything below 100 pounds pressure in the tires. I think that is asking for trouble, jus my opinion. BTW, in case you wish to see the charts and have misplaced the info that came with your mh, you can go to www.toyo.com and get all the info and they also have an email link where you can write to them with your concerns.
Ray

2000 Intrigue 11040

40 Ft. Gourmet on the Road

Re: Tire Pressure

Reply #103 –
Yahoo Message Number: 1943
Thanks Ray. I have the charts. My next step is get the coach weighed and balanced, then I can do the calculations and make my decision on what pressures I will be happy with.

It was interesting to read the various pressures people use.

Out of curiosity I would be interested to know what the tire pressure becomes after the coach has been running at speed for thirty minutes.

I guess those that have smart tire can read their pressure when cold, then get a reading of temperature and pressure after running at speed. If anyone has this information and would like to share it would be of interest.

David & Karen,
2000 CC Intrigue 11062
40 ft. Gourmet on the Road

Re: Tire Pressure

Reply #104 –
Yahoo Message Number: 1944
I've found a huge difference in pressures hot vs cold with smart tire.. as much as 20lbs difference

Re: Tire Pressure

Reply #105 –
Yahoo Message Number: 1958
We find that our tires go from 115 at 65 degrees to 129 at 90 degrees. that is from our smart tire. Temperature stays around 135 degrees in the tires.

Bill G.

Tire Pressure

Reply #106 –
Yahoo Message Number: 6556
For those interested:
The "Intellivalve.com"

web site is back up and running. Nothing yet on our RV sized units, but you can download the User's manual and service manual.
The tires must be un mounted to install the sending units.
James M. Green

Re: Tire Pressure

Reply #107 –
Yahoo Message Number: 12966
I have monitored the smart tire gauge frequently and find that the pressure increases between 10 & 15 pounds when driving, only takes about 10 miles to pick up 10 pounds. When cold the dual rears are set at 90 pounds, fronts at 110. After the 10 miles the dual rears are up to 100 and fronts 120 recorded on the gauge. When running at 110+ outside temperature, they have reached 105 and 125. In Arizona, we have had numerous tire failures due to extreme heat. Pressure monitoring is critical. More pressure is better than less. John 2002 Allure
#30702

Re: Tire Pressure

Reply #108 –
Yahoo Message Number: 12972
I monitor the smart tire gauge also - found the same results except we start at 100 pounds. The inside rear tires tend to run hotter - apparently because of brakes or circulation - A few months ago we left Boise - register said inside rear tire low - filled it to 100 lbs. - drove to Arizona - left Arizona a few weeks later - inside tire again low - filled it - went to California and around and up north of Reno - register again said low - finally had the tire pulled and checked - we had a very slow leak in the stem - So since we there we had them take the old air out and put new air in - Smart tire is a good thing

CHEERS - Clint

2004 Inspire #51038

Tire Pressure

Reply #109 –
Yahoo Message Number: 65211
Well, I am a bit confused now. I have been setting my tire pressure at what I considered a normal "cold" temperature of 72 degrees. If the weather is colder, I would adjust the pressure accordingly, using a chart which I think someone on this group directed me to. The chart says, for example, that if the correct pressure at 72 degrees is 100 lbs., then at 60 degrees you should be at 96.8. Now I read in Motorhome magazine that you should never be at a lower pressure then the indicated cold inflation, no matter how cold it is! And that you should inflate to that pressure and then let some air out after driving and the tires warm up! ("Coach and Powertrain" by Ken Freund, December issue, page 60). To me, this risks overinflation, especially if you are heading out on a really cold day. What do others think? BTW, I downloaded Michelin's Inflation charts for RVs, and my tires, XZE2, do not show up on that chart for the size 275/70 R22.5. ??????

Al Colby

2000 Intrigue 10979

Re: Tire Pressure

Reply #110 –
Yahoo Message Number: 65216
Al, here is what I recommend, and I'll keep it short and simple.
To start, an easier/closer T (temperature) P (pressure) relationship is 2 PSI for every 10 degrees change. So 100 PSI at 72 degrees would read or be set at 98 PSI at 62 degrees. I think the 3.2 degree Fahrenheit change you quote is wrong.

Determine your correct tire pressures (by the tables) at 72 or 70, either is fine, no big deal. Add an additional 5 to 10 PSI to the correct pressures on each tire. This a 'safety margin' and will not cause a problem as long as you don't exceed the max pressures stamped on the rim. Also the tires will wear better.

Inflate your tires accordingly. Your done.
Forget the daily tweaking of P based on daily T changes. you have that 5/10 PSI safety margin, which will accommodate 25/50 degree T swings.

That's it.

I've used this procedure for years, its recommended by others, its safe. Other than monitoring tire pressure for leaks, I usually adjust P once every 6 months max.

Lee Zaborowski

07 Intrigue 12153, Cat C-13

Re: Tire Pressure

Reply #111 –
Yahoo Message Number: 65218
Al,

I agree with Lee. I cap my extra PSI at 5 psi, but I also round of my weights too, so probably pretty close.
On my XZE's, 12R's, I called Michelin support, as I could not find my size tire either. He had me drill down into the site a different way, and noted that it was a site flaw. If I can remember how to drill into it, I'll send you a PM. (I printed out the data, when I did get in...)

You could call them, and see if the could get you in the same way.

Good luck,
Smitty

04 Allure 31017
04 Allure Sold to a nice new owner! Now enjoying a 07 Magna Rembrandt 45' ISX600 #6775
"We're ONDROAD for THEJRNY!" (Toad and Coach license plates, say Hi if you see us!)

Re: Tire Pressure

Reply #112 –
Yahoo Message Number: 65224
Al,

I agree with Lee, but I go a step further and make it even simpler. I have Toyo 111Z's on my coach and, at my fully loaded weight, Toyo's chart recommends cold inflation pressure of 75 lbs, front and rear. I have Accuride rims with 120 lb maximum pressure warnings stamped on them. I inflate the tires to 90 lbs cold and keep them there all year around. When ambient temperature drops in the winter I have to add a few pounds, and vice versa when spring and summer rolls around. I check the SmartTire system occasionally when driving and have observed that hot, rolling pressure rises 12-15 lbs over cold so I am staying well below the 120 max.

Nate Richards
04 Allure 31043

Re: Tire Pressure

Reply #113 –
Yahoo Message Number: 65229
This has to be one of the most confusing parameters of MH operation. You will get recommendations that are more varied than colors of the rainbow. I've questioned this for years and changed my procedure many times. And I have found they all work. Some require more attention than others. I've presented this question to Michelin, Goodyear and Bridgestone. Mostly what you get is CYA stuff. They all, at first, say go by the manufacturers recommendation. That of course is the maximum the tires/wheels allow. You can never go wrong with that.
Here is what the all say after a second inquiry. Determine the weight on the tire and use the tire inflation tables, adding some pressure for a margin of safety. Now, here's the rub, the tables say cold inflation pressure. What the heck does that mean? What is cold? Turns out cold means they have not been driven on for 3 or 4 hours or externally heated like by the sun, etc. The actual ambient temperature is not a factor. If the cold pressure is 100# and the ambient temperature is 65 degrees, then pressure should be 100#. If the ambient temperature is 95 degrees, set the pressure at 100#. This goes against what you read here, but, honest to god, that is what they all say. Don't want to start a pi----g contest, reporting my findings. So that's what I do and have never had a problem.

That's my story and I am sticking to it.

Jim

Re: Tire Pressure

Reply #114 –
Yahoo Message Number: 65235
The Les Schwab place in Junction City told me to go by the placecard on the panel next to the drivers seat to set tire pressure at cold temp (before driving). I just bought new Michelins for the front and still running the old toyos on the drive and tag (for about two more weeks until I replace them too). Their guru down there (I think his name is Paul) told me the fronts on my coach are to be set according to the factory specs assuming that you have the tire size that is called for. For my coach that was 120 lbs on the front and tag and 110 lbs on the drive.
I have the acccuride rims stating 120lbs max but that is the cold max pressure not the running pressure. My 12Rx22.5's have higher weight capacity if the tires are at 120lbs than at 85lbs. My rig is one heavy coach (C12 engine) and requires the 120lbs in the front and tag tires or else those tires are going to get really hot with the additional amount of flexing on the sidewall and tread on the road at lower pressures.
I had a front end alignment guy tell me that 110 was sufficient for my front tires just after I bought the coach three months ago so I ran with them at 110 with the drives at 100lbs. My smart tire monitor showed me at least a 22 lbs air pressure rise on the freeway as the temperature rose.
After pumping them up to 120 lbs (cold) my tire pressure now only increase by 17 lbs under the same road conditions and outside air temperature. The tire temperature obviously was lower at the 120 lbs cold. What did I learn, follow the placecard, and what the tire manufacture liturature confirms, well at least until I confirm what my normal weight is going down the road is what the placecard assumes.

Dallas 2004 Intrigue Ovation 42'

Re: Tire Pressure

Reply #115 –
Yahoo Message Number: 65242
Dallas, the one set of information you did not mention and do need is the actual weight at the six tire positions. You must have that information, otherwise all else is a guess.
Then, it's my recommendation that you follow the sequence I outlined earlier in this thread.

lee

Re: Tire Pressure

Reply #116 –
Yahoo Message Number: 65245
May be I missed something (my age anything possible) Factory specs are max specs.
Here again is a tire guy that hasn't done his home work keeping up with all the resources available and passes on questionable advice.
New Michelins a great new ride you will enjoy with those premium tires. Then why would you ride down the road sitting on a park bench ? We are not hauling freight, we are not hauling rock. Why not enjoy the ride ?With the following suggestion, you will be amazed.....
Step one...find a place to weigh your coach. Flying J, $9.00 appox Step two... fill fuel tank nearly full, water nearly full, normal gear onboard.
Step three... drive to weigh scale and weigh the coach to obtain 6 point readings from all your tire positions.
Step four... go to Michelin tire inflation guide and find your tire size and with the axle weights find your suggested cold pressure settings. At the least weigh each axle separate, if unable to do a 6 point weigh.
Let us know,
AL

00 Affinity

Re: Tire Pressure

Reply #118 –
Yahoo Message Number: 65252
I agree with you Lee. I love this forum because I pickup so may diverse ways of solving a problem or looking for answers. oh and turning your coach into a money pit at the same time.

Dallas

Re: Tire Pressure

Reply #119 –
Yahoo Message Number: 65254
Dallas, great! One more fine point. You'll find the right side and left side tire/axle weights will be different. Use the weight and relevant pressure for the heavier side, on both sides.

Lee

Re: Tire Pressure

Reply #120 –
Yahoo Message Number: 65260
I had a e-mail on weigh-in at Flying J . It's a no brainier easy as driving out of your driveway. Pull up to the scale and a posted sign will give you 2 options. Everyone stays in the coach, tow car can even stay on. You could even weigh the tow car if you wish.
A) call in via CB on there posted channel.
B) call on your cell phone.

Let them know what you want to weigh, you will be told to drive on and stop at there weigh points.
Pulling off the scale you can park or go to fuel pumps etc. When you go inside the weigh invoice will be there. Hand over the moo-la and that's it.
AL

00 Affinity

Re: Tire Pressure

Reply #121 –
Yahoo Message Number: 65261
AL,

Try going through the main Michelin site. Follow the prompts and you will end up with a break down per rim size..ie 22.5. There lies detailed air pressure/axle load.
AL

00 Affinity

Re: Tire Pressure

Reply #122 –
Yahoo Message Number: 65268
So what is the pressure chart under on the michelin web page? I just looked and cannot find it.

Bob Nuttmann

2002 42' Affinity

Re: Tire Pressure

Reply #124 –
Yahoo Message Number: 65277
No problem...

www. Michelin.com Select your country
arrow to North America
hit United States
hit recreational

hit load inflation tables
choose wheel dia...ie 22.5
scroll to your tire size
AL

00 affinity