Date:         Fri, 8 Dec 2006 16:45:29 -0800
Reply-To:     Loren Busch <starwagen@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Loren Busch <starwagen@GMAIL.COM>
Subject:      Re: Michelin Tire Experiences
Comments: To: Jeff Palmer <jpalmer@mts.net>
In-Reply-To:  <0BC6C551-253E-404F-BE3A-374BB7D70D96@mts.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

RE: Nitrogen an Low Inflation
The use of dry nitrogen in tires has been around for a long time, especially
with racers.  The object is not to get rid of oxygen or ozone but to get rid
of moisture, water vapor in the tire.  This keeps the heating to a minimum
inside the tire and keeps the pressure down as the tire heats up.  More
consistent shape to the tire, more consistent performance.  And there are
two problems combined with running with low tire pressures in addition to
the handling and possibility of popping the bead.  At lower pressure the
sidewalls flex more.  This causes more heat build up. Now the hot rubber is
being flexed more than was intended in the design and can lead to
separations and early failure of the rubber compound.

One way to check inflation on your tires is to use a small IR thermometer
like those available from Radio Shack.  When heavily loaded I'll check the
temperature of all four tires the first time I hit a rest stop or stop for
gas.  I expect to find the temps nearly the same for all four, indicating to
me that the combination of pressures I'm running front to rear is putting
the same stress on all four tires.  On at least one occasion I found one
rear tire running about 20 degrees hotter than the others, checked the
pressure and it was down almost ten pounds.  Pumped it up and the next time
I checked temps were equal.