36 01 06 (251) Inflating Tires With Nitrogen (N2)

36 0106 (251) Inflating tires with nitrogen (N2)

All series

Situation:
The question is regularly asked, whether inflating the tires with nitrogen instead of air has any benefit with respect to a "gradual loss of tire pressure". This process is also known as diffusion (diffusion is the movement of minuscule particles, especially atoms or molecules).

Statement
Some companies regard inflating the tires with nitrogen as a way of selling the customer a feature that has no practical benefit whatsoever with respect to diffusion. As nitrogen has larger molecules, it would indeed be logical to argue in favor of inflating the tires with nitrogen instead of with air. However, the improvement achieved is only marginal because air is anyway made up of about 78 % nitrogen.

Composition of air:
^ 78 % nitrogen (N2)
^ 21 % oxygen (O2)
^ less than 1 % inert gases
^ 0.03 % carbon dioxide (CO2)

The reduced rate in the drop in pressure inside the tire is just a few hundredths of a bar over several months. Inflating the tires with nitrogen does not relieve the driver from his duty (described in the Owner's Handbook) to check the tire pressures regularly. Nitrogen is used in aviation and in motor racing because, in the event of an accident and the associated risk of fire, no additional oxygen should be fed from the tires.

Affected vehicles:
All series

Procedure:
Recommendation
BMW does not recommend inflating tires with nitrogen. Should individual customers wish to have their tire inflated with nitrogen, their wishes may be accommodated.