Nitrogen for Tyres?

We have heard of nitrogen being "marketed" as almost compulsory as part of your tyre change- whether it is for free or for a charge of $10/ $20 per tyre.

Just how much do we need nitrogen for our tyres?

You may already know the air used to inflate tyres at your neighbourhood pump is already more than 75% Nitrogen- the rest being oxygen (about 20%), and other gases. Would it then be better to further purify that 20% or so?

Comparing nitrogen to normal air- nitrogen is known to be a dryer and therefore more stable gas, which is not affected due to changes in pressure. This ensures a relatively well inflated tyre, compared to normal air, which also leaks 1-2 PSI a month. It is also said that nitrogen being lacking in oxygen and water vapor do not corrode the wheels and valves, resulting in further consequences from lowered tyre pressure.

It is known that air crafts and race cars use Nitrogen, but in these cases, the slightly difference in hot/ cold inflated pressure makes a big difference. Just how much are we average drivers going to benefit?

Would 1 PSI pressure result in major difference travelling at 90km/h average? Would your alloy wheels corrode? Would paying $40 to $80 be justifiable, especially when a leak would mean a quick fix at the neighbourhood pump (of normal air)?

Tyrepac has always allocated regular inspection, and nothing replaces this ritual, not even nitrogen. Drive safe!