Originally Posted by chops

get your facts straight. there's no fake science in this thread. if you actually bothered to google, as i just did, you will see that nitrogen molecules are in fact larger than normal oxygen molecules. pure nitrogen inflated tires will leak less and are less susceptible to temperature/psi variations as well as being lighter than your typical air (4% lighter, however fuel savings are negligible at best). while our air is 78% nitrogen anyway, the rest of the gases you fill into your tires will find their way out faster, hence why pure nitrogen is used more commonly today.