At 01:52 AM 8/30/2010, Don Hanson wrote...
>minimize heat-generated pressure increase.  As a tire comes up to
>racing
>temp with atmosphere inflated inside, they can gain up to 7psi but
>with
>nitrogen, they will only gain a few lbs....So when you filled the
>tires with
>nitrogen, you could start a race with almost the correct pressures,
>rather
>than running a lap or so underinflated while the temperature caused
>the
>pressure to increase.

BS. Air is 78% nitrogen to begin with. All gasses follow Gay-Lussac's
Law extremely closely, unless at temperature extremes (think absolute
zero and plasma heat). There are 2 legitimate reasons to use N2 in
tires - the military uses it in some aircraft to eliminate a fire
hazard from the oxygen in air, and race teams use it because a bottle
is cheap, and can be used to fill tires without needing either a
compressor or electricity (or they believe the BS the N2 salesman told
them). A third reason to use N2 is so tire stores can make additional
profit.