How And Why Do We Fill Tyres With Nitrogen?

How do we fill tyres with nitrogen?

While we typically fill our car tyres with normal

air, Formula 1 teams and even airlines fill their

vehicles’ tyres with purified nitrogen. They do this to

boost performance and reliability, so should we be

doing the same?

The air you pump into your tyres is actually mostly

nitrogen anyway – 78 % of it to be exact – but

it’s the other 22 % that is the problem. Less

than one percent is water vapour, which at very low

temperatures, such as those at high altitudes, and

very high temperatures, such as those produced when

driving very fast can freeze or expand to make the

tyre pressure unstable. For normal driving though,

this shouldn’t be a problem, so dryer nitrogen won’t

make much difference.

However, air is also 21 percent oxygen, and as

oxygen molecules are so tiny, they drip through

the tyre rubber over time. Nitrogen molecules on the

other hand, are bigger, so they stay inside the rubber

for longer and mean you have to get the tyres

pumped less often.

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