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Topic: Tire Inflation (Read 2147 times) previous topic - next topic

Tire Inflation

I weighed our coach the other day.
The scales were about 9 miles from our house at temp in the lower forties so I guess they were cold.
I attached the results.
So my front axles are at 11280
And my rear are at 19260.
My tire pressure all around was set at 90.
The front are ok at that.
But the back based on the weight should be at 85 based on the chart from Foretravel.
Does that sound correct?
I just don't want to make any mistakes when it comes to tires.
Also the tow vehicle weighs 5220 lbs. Does that have any impact on the tire pressure of the back tires.  It is flat towed.

Re: Tire Inflation

Reply #1 –
The weight of the towed has nothing to do with bus tire pressures.

Re: Tire Inflation

Reply #2 –
Don't know where FOT gets their information on tire pressures.

For best results, use the tire pressure chart published by the manufacturer of your tires.

Always check the pressures when tires are cold (early in the day before the sun hits the tires).

Re: Tire Inflation

Reply #3 –
And yet another worry over tire inflation. Not trying to make fun of you, Pyolet, but there has been so much discussion on this subject and so many folks seem to obsess over this.... Anyway, I had a friend with a CC of the same year and basically the same configuration as my '96 U295. He checked his tire pressures so often that it affected his inflation values. Every time you check you lose a little air. Check often enough and you prove yourself right that your tires are going down. We full-timed for 18 years on tires that we checked once a month. kept them between 85 and 90 psi. All was good, never had a problem except for punctures. Just driving up a steep hill will increase your tire pressure. Actually, anything that heats the tires up changes things. We set the pressure at 90 psi and when it got to 85 psi we raised it back up. Tried to do the checking under the same conditions as best we could. WE ran our tires 6 to 7 years depending on how the sidewalls looked. I think you're good to go. Safe travels.

Re: Tire Inflation

Reply #4 –
My Uniroyal tires are all at 110 psi in all 6. My dealer only does trucks and heavy vehicles. My max on tires is 120. My techs all said stay at 110 and quit worrying so that's where they are set . Go by the tire, not the old FT info.

Re: Tire Inflation

Reply #5 –
How's the ride Dan?

Re: Tire Inflation

Reply #6 –
Quote from: dans96u295ft –
My Uniroyal tires are all at 110 psi in all 6. My dealer only does trucks and heavy vehicles. My max on tires is 120. My techs all said stay at 110 and quit worrying so that's where they are set . Go by the tire, not the old FT info.

Actually, the statement should be: "Go by your new tire manufacturer's inflation table for your actual weight."  Agree, if tires are different than OE, the PSI on the GVWR sticker may not be accurate for your new tires.

Re: Tire Inflation

Reply #7 –
My experience long ago was that overinflated tires rode worse on poor roads and had a smaller tread contact patch pressure area.  The edges had less pressure holding the tire to the pavement.

Probably why the tire manufacturers have a pressure vs load chart?

Re: Tire Inflation

Reply #8 –
Quote from: dans96u295ft –
My Uniroyal tires are all at 110 psi in all 6. My dealer only does trucks and heavy vehicles. My max on tires is 120. My techs all said stay at 110 and quit worrying so that's where they are set . Go by the tire, not the old FT info.
Bingo!  Someone got bad info when new Michelins were installed on ours: she was inflated to 100 psi all around and rode terrible. I had her four corner weighed, called Michelin and went down to 85 front 80 rears; MUCH BETTER RIDE. b^.^d

Re: Tire Inflation

Reply #9 –
Quote from: Chuck & Jeannie –
Don't know where FOT gets their information on tire pressures.


I believe the sticker/plate tire pressure weights are based on the OEM tires (brand, model, size, and load range) and the pressures listed on that sticker are for the GAWR of each axle as applied to the load inflation table for the OEM tires.

As Brett said:

 
Quote from: wolfe10 –
Actually, the statement should be: "Go by your new tire manufacturer's inflation table for your actual weight."  Agree, if tires are different than OE, the PSI on the GVWR sticker may not be accurate for your new tires.

Re: Tire Inflation

Reply #10 –
Thanks. 
I have Michelin.
I will see what they recommend.

Re: Tire Inflation

Reply #11 –
Did you happen to weigh your coach with what you normally carry in terms of fuel, fresh water and normally stowed cargo in the bays? Did you include the normal number of human and animal cargo with you when you weighed? In my case, full tank of 148 gallons of diesel at 7lbs/gal is 1036lbs and with family traveling with us adds some more... thus increasing actual loads on the tires.

Re: Tire Inflation

Reply #12 –
Sure you did not mean wander?

Re: Tire Inflation

Reply #13 –
Yes, Wander! Thanks for letting me know :)

Re: Tire Inflation

Reply #14 –
I'm coming from a gasser which rode terrible all the time, so at 110 psi with the bags, it's very smooth compared to what I'm used to. The bigger picture is no blowouts so 110 it is

Re: Tire Inflation

Reply #15 –
Quote from: dans96u295ft –
I'm coming from a gasser which rode terrible all the time, so at 110 psi with the bags, it's very smooth compared to what I'm used to. The bigger picture is no blowouts so 110 it is

How much is that over the MIchelin/Uniroyal recommended minimum PSI for your actual weights? 110 PSI is only relevant as compared with your tire manufacturer's recommendation.

Re: Tire Inflation

Reply #16 –
Quote from: dans96u295ft –
I'm coming from a gasser which rode terrible all the time, so at 110 psi with the bags, it's very smooth compared to what I'm used to. The bigger picture is no blowouts so 110 it is

I've attached the Uniroyal commercial tire inflation book. For 275-80-22.5, 110 lbs., that takes you to 22,750 on your rear axle, (check your plate, it is probably only 19,500) and 12,350 on the front axle, (which is probably only rated at 10,500). So it appears you are overinflated by 20 lbs. The pressure you've been recomended is too high, so I would at least weigh sometime when fully loaded and check with Uniroyal book for your tire size or at least do not overinflate beyond your axle capacity.

Re: Tire Inflation

Reply #17 –
Overinflated tires hydroplane easier as the edges are lighter loaded.  Slide on ice easier

Re: Tire Inflation

Reply #18 –
The max. is 120. The tire shop that fixes many many tires on I-70 are the ones that wanted 110 with 36,000 possible pounds so I really respect their opinion but like oil, tire pressure has many many ideas and opinions. We also get to 105-107 in the summer so that factors in. They see more blowouts for under pressure than anything else. Age is number 2 failure. They also don't like to use screw on tire valve extensions. Their opinion is 90% of them leak and cause under inflation. They actually have a steel bend that is long enough to easily test and air up the inside dually without the extensions so that's what I'm running

Re: Tire Inflation

Reply #19 –
STOP.  Did they ask you for the actual weights of your wheel positions or even axles???

On exactly what did they base their opinion???

Unless clairvoyant or they had the above information, they could be off by 20 or more PSI from the engineers who designed your tire.

Said another way, I would sure trust the advice of the engineers who designed your tire, rather than a guy who sold/mounted them.

Yes, we go through this several times a year and have for the last 20 years.

Off my soap box now!