Have you ever seen a car with lovely green valve stem caps on the wheels and wondered why they were there? They don’t usually match anything on the car and stick out like a sore thumb. Unless you have a twisted sense of taste, why would you put green valve stem caps on your car’s wheels? The answer is nitrogen. Green valve stem caps serve as identification that the tires are filled with nitrogen, rather than compressed air. In this article, we will examine the merits of using nitrogen to fill your tires.
The air we breathe (and put into our tires) already contains about 78% nitrogen, 21% oxygen and 1% other gases. We need the oxygen but our tires may not. Here are few supposed benefits for running nitrogen in your tires:
More consistent tire pressure
Oxygen molecules are very small compared to nitrogen. Because of the size difference, oxygen is able to pass through and around tire rubber which may produce a 1% to 5% loss in tire pressure every month. Nitrogen molecules are too large to easily pass through tires, which minimizes decreased air pressure. Consistent proper tire pressure provides for a number of benefits, including better fuel economy.
Oxygen loves to hook up with hydrogen to create water. Increased humidity is not desirable in a tire. Too much moisture in a tire will contribute to quicker corrosion of wheels (commonly called rim rust) and a greater sensitivity to ambient air temperature, resulting in swings in tire pressure. Nitrogen is much dryer than compressed air, keeping wheels and tires protected from the damage caused by excessive moisture.
Increased tire life
Because nitrogen keeps the tire properly inflated longer than compressed air, tire wear issues associated with under-inflation are significantly reduced. Nitrogen is an inert gas, so it will not contribute to seal, valve or tire liner degradation.
There are many opinions regarding the use of nitrogen in tires. There are studies that support the information presented above. There are studies that conclude that nitrogen offers no significant benefit over compressed air. It is worth noting that nitrogen is widely used by NASCAR teams, trucking companies and commercial aircraft for tire inflation.
What do you think: help or hype?