Tire inflation

Goldencrazy wrote:
After weighing I find my front tires are inflated too much. The sticker on sidewall says 90psi but the Michelin chart has them between 80 and 85. Is this typical that sidewall charts are a bit high? Does five lbs mean much in terms of ride? Finally when using the weight on rear do I divide by two for dual weight?

First, the pressure written on the sidewall of a tire is a MAXIMUM (with some exceptions).

The way this is usually written is: Max Load XXXX at YY pressure. Please observe this is a relationship.

Second, just because this states a relationship at one particular point, doe NOT mean that you should use that pressure for every situation. That is sort of what those charts are for.

EXCEPT: Over the years, it has been learned that it is a good idea to use more pressure than the minimum the tire load charts indicate 9which are MINIMUMS!!). I think the value is 15% more load carrying capacity - which is around 10 psi.

My Michelin & Winnebago Chart said to run my 22.5's on my coach at 85 lbs. rear and 90 front! I was experiencing rear tire squirm at those pressures! I experimented with different tire pressures and ended up running 100 lbs. all around. It has worked out very well for me, a tad rougher ride, but my tire wear couldn't have been better I was able to run my first set 10 years with no problems and I'm in the second year with no problems on my current set!

Dont use the lists the tire maker gives.
Michelin even uses a different list in Europe then America.
The EUR list comes to lower loadcapacity for the same pressure.
This means that the advice pressure would be higher, when looking in EUR list.

Best is to give me the GAWR's and GVWR of your motorhome, or better if you ever weighed those data(reading back I see you did, was it per axle or wheel(pair)

Then from tires maximum load and pressure needed for that and speedcode of tire.

Then I will calculate a pressure with as much possible reserve but still acceptable comfort and gripp.
And that will be mayby even 15 psi higher then when looking in list.
So higher then list is no problem, even better for livetime of tires, and lower chanche on tire failure.

Greatings from a Dutch self declared tire-pressure-specialist.

It's a good idea to go atleast 5 psi over the chart because a good cross wind will shift enough weight and the down wind tires can be 8-10 degrees warmer than normal.

I always put 5 to 10 pounds in over what the chart says. I use this as a fudge factor. When I went to the freightliner class the instructor also said to do this.

My friend had same thing ,called Mich they said follow their chart