Qusetion by: Gareth Coats Answer by: Johann ViljoenI’d like to know the pros and cons of filling my tyres with nitrogen instead of regular air. It seems the advertised benefits are true, but I’m unclear as to whether or not it makes a huge difference and if it would be beneficial in my 4×4’s case, especially considering the possible dangers of mixing nitrogen with normal air.
Apparently, mixing air with nitrogen leads to density differences and therefore pressure variations, uneven tyre wear and reduced tyre lifespan. If this is true, could I not re-inflate my nitrogen-filled tyres with my portable air compressor? Is the advice we’re getting worth considering?
Gareth Coats
THE EXPERT’S OPINION:
Nitrogen reduces the running temperature of a tyre thanks to its moisture content. The cooler you keep a tyre the longer the tread will last. This is particularly true for heavily loaded vehicles travelling at high speed.
What’s more, nitrogen is said to be far more stable in terms of its pressure / temperature relationship, exhibiting only mild fluctuations when the tyre heats up. But again, the benefits here are only evident in high-load / high-speed situations.
Furthermore, due to the porous nature of tyres, they’re susceptible to seepage and air loss, however, thanks to the chemical structure of nitrogen this gas takes longer to escape.
Lastly, oxygen can be corrosive, causing oxidation or the formation of rust within the tyre or on the rim itself. Nitrogen, being an inert gas, has no reactive qualities with either material – tyre or rim.
The abovementioned qualities aside, some of the drawbacks to nitrogen include cost (it’s expensive) and convenience (it isn’t widely available). I’d stick with plain old air as it’s readily available and free. Moreover, air is 78 percent nitrogen, so I can’t see cause for concern with regards to mixing the one with the other.
Johann Viljoen
First Alignment Centre
(021) 949 5041
