tire weight air vs nitrogen

["Benn" <karhu@california.com>]

Pretty surprising, considering that air is 80% nitrogen, oxygen makes up most
of the rest, and it weighs almost the same as N...


  It also helps that the tires in NASCAR are no longer filled with air but
with nitrogen.  This was something we used to do 25 years ago on big rigs
because it not only was better for the tires, it actually affected what showed
up on the scales.