看看吧，看他们如何忽悠。
From the Canadian Tire website:
Benefits of Nitrogen Tire Inflation
Over the past few years, service centres have begun offering drivers a new option for keeping their tires inflated – nitrogen. However, for many drivers it is unclear why they should consider inflating their tires with nitrogen rather than compressed air.
Compressed air is composed of 78 percent nitrogen, 21 percent oxygen, and small concentrations of other gases; therefore, nitrogen is basically compressed air with oxygen removed. However, the differences go a bit further. Nitrogen molecules are larger than oxygen molecules. This difference in molecule size makes it more difficult for nitrogen to escape through your tire sidewalls, allowing your tires to maintain optimal pressure for longer periods of time. Keeping your tire pressure constant increases the overall safety of your vehicle, and can help save costs associated with fuel economy and overall tire maintenance.
It is common for tires inflated with compressed air to develop a buildup of water vapour inside the tire, which can cause steel and aluminum wheels to corrode. It may also affect your TPMS sensors and their ability to produce accurate readings. Nitrogen produces significantly lower levels of humidity, reducing the potential for corrosion, and supporting optimal performance of your TPMS sensors. Aircraft tires often use nitrogen as they are subject to drastic changes in temperatures and the water vapour associated with compressed air is at risk of freezing during flight. Nitrogen is also used in NASCAR racing tires due to their ability to control temperature changes.
Nitrogen does have some drawbacks that should be noted. Despite its ability to slow the process of disinflation , it is still possible for your tires to lose pressure over time. When this happens, a nitrogen-filled tire must be topped off with nitrogen if the benefits previously mentioned are to be maintained. Otherwise, the addition of any amount of compressed air to a nitrogen-filled tire will necessitate the full deflation of the tire before re-inflating it. Lastly, while nitrogen can save you money by refilling less frequently, it costs more than compressed air at the pump.
