Nitrogen is a colourless, odourless, non-toxic gas that makes up 78% of the earth’s atmosphere. It has been used to inflate tyres of racing cars, aircraft and heavy commercial vehicles for some time, and is recently gaining popularity for use for inflating tyres of normal passenger vehicles.
Some benefits claimed for inflating your car’s tyres with nitrogen instead of normal air, include that it will reduce the running temperature of your tyres, improve ride quality, increase tyre life and keep tyre pressure more constant, slow the rate of pressure loss and finally, that it will not react with the tyre and rim materials. Let’s examine these claims a little more closely.
Reducing the tyre’s running temperature – there is some truth to this claim, however, this is caused by the lower moisture content of the nitrogen gas. Dry compressed air will also ensure that your tyre will run cooler, and any likely benefit will only be of importance where your tyres are running at or near their maximum load and speed.
There is no valid reason why nitrogen would improve your ride quality at normal tyre operating pressures and temperatures.
Tyre life will increase slightly with a lower operating temperature – however there are some claims that using nitrogen will double the life of your tyres, and this is in all probability not going to be achievable.
The pressure inside a tyre will increase as the operating temperature increases, and nitrogen could provide a more stable pressure as a result of the lower operating temperature – however, you are only likely to notice benefits under heavy loads and/or high speeds.
The chemical structure of nitrogen means that it will be slower to leak out of your tyres than normal compressed air – this is true, but you still need to check your tyres regularly in case of a leak.
In tyres filled with compressed air, you could experience oxidation/rust of the metal components of the wheel rim. It is also claimed that the compressed air reacts with the rubber of the tyre – but there is no evidence pointing to whether this reduces the life of the tyre or not. Nitrogen, being a relatively inert, dry gas means that in theory, this problem is prevented. However, this is offset by the fact that there is probably still some air in the tyre which means that your tyres won’t have 100% nitrogen content.
You also need to consider that nitrogen may not be readily available near to your home or office – and this may lead you to neglect a regular check on your tyre pressure.
Normal compressed air contains 78% nitrogen anyway – so it is likely that the benefits of using pure nitrogen in your tyres are overstated. The most important factor in looking after your tyres is regular maintenance which includes regular checks on your tyre pressure, wheel balance and alignment.