Nitrogen in tyres
Why should I be aware of this?
Tyres filled with nitrogen are believed to stay for at least six months, thus eliminating the hassle of quick succession pressure check. Nitrogen in tyre also improves fuel efficiency by almost 8% in addition to maintaining constant pressure for a longer period of time and increasing the life span of tyres.
How does this affect me?
As nitrogen molecules are bigger and lighter than compressed air, they keep the weight low and improve fuel efficiency. The leakage of nitrogen is minimal as compared to compressed air (mixture of oxygen and water vapors) which leak through the tyre structure, causing pressure drop.
Nitrogen in tyres and environment
There are no environmental issues as nitrogen is relatively inert. Those advantages are important in vehicles equipped with tyre pressure monitoring systems, which are sensitive to changes in tyre pressure. If the tyres are kept properly inflated motorists can improve gas mileage by 3.3%.
All about nitrogen in tyres
Nitrogen has been used for years in the tyres of race cars, large commercial trucks, aircraft and even the space shuttle. But it is finding its way into the mainstream at a growing number of tyre dealers.
There are special advantages of using nitrogen in specialist applications. These are:
- Planes fly at heights where temperatures may be as low as -40C. If there is residual moisture in the tyres, they can freeze and cause vibration and balance problems during landing. Pure nitrogen being dry eliminates this problem.
- In motor sport the smallest fraction of a second can make the difference between winning and losing. Filling with nitrogen can reduce tyre pressure variation caused by changes in tyre temperature.
As nitrogen molecules are bigger than oxygen molecules, they seep out of the tyres more slowly. Nitrogen resists heat build-up better than air and reduces oxidation, which can damage the tyre from the inside out.
For passenger cars nitrogen gives the following benefits
- With nitrogen in tyres there is reduced corrosion because unlike air there's no moisture in pure nitrogen.
- As nitrogen molecules are larger than oxygen molecules (which make up 21% of compressed air) there is slower rate of pressure loss.
- Pure nitrogen leaks more slowly through the liner. Leakage can occur through the tyre's inner liner but can also occur through the valve, punctures, or failure of the seal between tyre and wheel rim. However, regular checks of tyre condition and pressures will still be essential.
- Changing to nitrogen involves removing all the air which is already in the tyres and then re-inflating them with purified compressed nitrogen. There will be a one-off charge per tyre but once filled with nitrogen any future top-ups would also have to be with nitrogen if any advantages are to be maintained.
Overall, while accepting the possibility of purified nitrogen being of benefit in certain applications, the cost and possible inconvenience may not be justified for normal passenger car use.
In the real world, though, only 1 in 5 motorists check tyre pressure regularly, according to the Rubber Manufacturers Association. Nitrogen, therefore, could have an advantage for those who don’t check their tire pressure regularly. 
- Nitrogen fills could save tyre wear
- Tyres inflated with nitrogen
- Try nitrogen for extra mileage
- http://www.theaa.com/motoring_advice/safety/filling-tyres-with-nitrogen.html Filling Tyres with Nitrogen
- ↑ Try nitrogen for extra mileage