Helium in Tires

[derf <derf247@gmail.com>]

First, I can see putting Helium in.  I don't think it would make a big
difference.  But, while you are pumping the Helium in, how do you let
the air that is already present in the tire out?

Second, it seems that if there were advantages to alternative tire
gasses then the military, aviation industry, or auto racing people
would have been doing it for years.

Where are Mythbusters when you need them?