Gases
act relatively close to one another in their physical behavior. Volume of
gases act similar to changes in temperature, pressure, and the quantity of
gas.
PV=nRT
V=n or V=T but V=1/P
The amount of air, volume, in your
tires will effect your velocity (the above equation states this relationship)
For instance:
a flat tire will slow you down due to having less
volume
a fully inflated will give you optimum speed
an over inflated tire could blow because volume
exceeds surface area