Pressurized Air vs. Nitrogen
Pressurized Air vs. Nitrogen
Posted on September 28, 2020
Is there really an advantage to using nitrogen rather than air in car tires? Will is provide better fuel economy, a smoother ride, or longer tire life? The short answer is, some.
Traditionally, vehicle tires are filled with compressed air. Air is 78 percent nitrogen and just under 21 percent oxygen, and the rest is water vapor, CO2, and small concentrations of noble gases such as neon and argon.
Over time, a tire will gradually lose pressure. Changes in temperature accelerate this loss. The rule of thumb is a loss of 1 psi for every 10-degree rise or fall in temperature. Nitrogen has a more stable pressure than oxygen since its larger molecules are less likely to seep through the permeable tire walls. This results in more stable tire pressures over a longer period of time.
Some people prefer filling their car’s tires with pure nitrogen, and there are several compelling reasons to do so;
- Improperly inflated tires can wear unevenly, wear out faster, and ruin your fuel economy. Simply put, pure nitrogen does a better job of maintaining the right tire pressure, thus enabling your car and its tires to work as efficiently as possible. And thoughtire-pressure monitoring systems now come standard on most vehicles, a National Highway Transportation Safety Administration study found that only 57 percent of vehicles with monitoring systems had the correct tire pressure. That's because most systems are only meant to signal that a tire has very low pressure, not to show that the pressure is optimal. Presumably, nitrogen-filled tires would save us from our own laziness
- Tires filled with nitrogen rather than air react less to temperature swings. Gases expand with heat and contract with cold, which is why your vehicle’s tire pressure warning light usually comes on when colder fall temperatures hit. When air is pressurized, the humidity in it condenses to a liquid and collects in the air storage tank you use at the local gas station. When you add compressed air to the tire, the water comes along for the ride. As the tire heats up during driving, that water changes to a gas, which then expands, increasing tire pressure. Because nitrogen is dry, there is no water vapor in the tire to contribute to pressure fluctuations
- Wheel rot prevention. Whether it’s present as a vapor or even as a liquid in a tire, water causes larger changes in pressure with varying temperatures than dry air does. Worse yet, water also causes corrosion of steel or aluminum rims over time. Water is less of a concern with nitrogen-filled tires. Filling tires with nitrogen involves filling and purging several times in succession to get as much oxygen, water, and other gases out of the tire as possible.
Having provided the positives to using Nitrogen in your tires, remember, there is no substitute for proactive, regular tire care, maintenance, and proper inflation pressure to ensure tire safety and performance. There is nothing wrong with the standard method of using pressurized air but if you are looking for opportunities to gain peak performance, filling your tires with Nitrogen is a great option.