Can I Add Air to Tires With Nitrogen? An Expert’s Guide
Yes, you can absolutely add air to tires that are already inflated with nitrogen. While nitrogen offers certain benefits like slightly better pressure retention and reduced oxidation, mixing it with regular air won’t harm your tires or create a dangerous situation. In fact, the air we breathe is already about 78% nitrogen.
Understanding Tire Inflation: Air vs. Nitrogen
For decades, air – specifically compressed atmospheric air – has been the standard for inflating tires. In recent years, nitrogen inflation has gained popularity, often touted for its superior properties. However, the fundamental principle remains the same: inflating a tire to the correct pressure provides the necessary support for the vehicle’s weight and ensures optimal handling, fuel efficiency, and tire wear.
The Composition of Air and Nitrogen
Atmospheric air is primarily composed of nitrogen (approximately 78%) and oxygen (approximately 21%), with trace amounts of other gases like argon and carbon dioxide. Nitrogen, on the other hand, is nearly pure N2, often with a concentration of 95% or higher when used for tire inflation.
The Perceived Advantages of Nitrogen
The advantages often attributed to nitrogen in tires stem from its larger molecular size and its lack of moisture. Nitrogen permeates tire rubber more slowly than oxygen, leading to slightly slower pressure loss over time. It’s also an inert gas, meaning it doesn’t readily react with other substances, reducing oxidation of the tire’s inner lining and the wheel.
Mixing Air and Nitrogen: Is it Safe?
The short answer is yes, it’s completely safe to mix air and nitrogen in your tires. There are no adverse chemical reactions or risks of explosion. The primary effect of mixing is a reduction in the nitrogen concentration within the tire. However, the percentage of nitrogen would need to be significantly diluted before the benefits are substantially reduced.
Why Mixing Is Not a Problem
Think of it like diluting a concentrated juice. Adding water (air in this case) reduces the concentration of the juice (nitrogen), but it doesn’t make the drink poisonous or unusable. Similarly, adding air to a nitrogen-filled tire simply decreases the percentage of nitrogen, bringing it closer to the composition of regular air.
When to Consider Completely Re-Inflating
While mixing is safe, if you consistently need to add air to your nitrogen-filled tires, it might be worthwhile to completely deflate the tire and refill it with air or nitrogen at a shop. This allows you to maintain a more consistent pressure and potentially reap more of the perceived benefits of nitrogen, if that is your preference. However, realize that the difference may be negligible.
Debunking Nitrogen Myths
Numerous myths surround nitrogen tire inflation. Let’s address some of the most common misconceptions:
Myth: Nitrogen Dramatically Improves Fuel Economy
Fact: While proper tire inflation, regardless of whether it’s air or nitrogen, contributes to better fuel economy, the difference between nitrogen and air is often negligible. The impact is far more dependent on maintaining the correct pressure than on the inflating gas itself.
Myth: Nitrogen Prevents Tire Blowouts
Fact: Tire blowouts are primarily caused by underinflation, overloading, tire damage, or manufacturing defects, not by the inflating gas. Maintaining proper tire pressure and regularly inspecting your tires are far more effective ways to prevent blowouts.
Myth: Nitrogen is Necessary for High-Performance Vehicles
Fact: While some racing teams use nitrogen to maintain more consistent tire pressures during races, for everyday driving, the benefits of nitrogen are unlikely to justify the cost. Maintaining proper pressure with regular air is perfectly adequate for most high-performance vehicles.
Frequently Asked Questions (FAQs)
Here are 12 frequently asked questions to further clarify the topic of adding air to tires with nitrogen:
1. Will adding air to my nitrogen-filled tires void my tire warranty?
No, adding air to your nitrogen-filled tires will not void your tire warranty. Tire warranties typically cover manufacturing defects, not the type of gas used for inflation.
2. How can I tell if my tires are filled with nitrogen?
Tire shops that use nitrogen often install green valve stem caps to indicate that the tires have been inflated with nitrogen. However, this is not always the case, so the best way to be sure is to ask the shop or refer to your service records.
3. Is it more expensive to use nitrogen for tire inflation?
Yes, nitrogen tire inflation typically costs more than inflating with air. Tire shops often charge a fee per tire for nitrogen inflation, whereas air is usually free.
4. Should I completely switch back to air if I keep needing to add air?
If you consistently need to add air and are no longer reaping noticeable benefits from the nitrogen, switching back to air might be a cost-effective option. You can deflate the tires completely and refill them with air at a local gas station or tire shop.
5. What is the ideal tire pressure for my car?
The ideal tire pressure is specified by the vehicle manufacturer and is typically found on a sticker on the driver’s side doorjamb or in the owner’s manual. Always refer to this information, not the maximum pressure listed on the tire sidewall.
6. How often should I check my tire pressure?
It’s recommended to check your tire pressure at least once a month, and ideally before any long trips. Pressure can fluctuate with temperature changes.
7. Can I use a regular tire pressure gauge with nitrogen-filled tires?
Yes, a standard tire pressure gauge works equally well with air and nitrogen-filled tires. The gauge measures the pressure inside the tire, regardless of the inflating gas.
8. Does nitrogen affect the accuracy of my Tire Pressure Monitoring System (TPMS)?
No, nitrogen does not affect the accuracy of your TPMS. The TPMS measures the pressure inside the tire directly, independent of the type of gas used for inflation.
9. Are there any specific tools needed to inflate tires with nitrogen?
While nitrogen inflation requires a specialized nitrogen generator, you don’t need any special tools to add air to tires already inflated with nitrogen. A standard air compressor and tire pressure gauge will suffice.
10. Is nitrogen tire inflation better for the environment?
The environmental impact of nitrogen tire inflation is debatable. While nitrogen itself is an inert gas, the process of producing and distributing it requires energy, potentially offsetting any environmental benefits.
11. Does nitrogen help prevent corrosion on my wheels?
Nitrogen, being an inert gas, can reduce oxidation and corrosion inside the tire and on the wheel. However, this benefit is relatively minor compared to other factors that contribute to wheel corrosion, such as road salt and moisture.
12. Are all nitrogen inflation services the same?
No, the purity of the nitrogen used for tire inflation can vary. Some shops may use nitrogen with a purity level of 95%, while others may use higher or lower concentrations. Higher purity nitrogen offers slightly more consistent pressure retention. However, for most everyday driving situations, the difference is negligible.
The Bottom Line: Safe and Practical
Ultimately, adding air to tires inflated with nitrogen is a safe and practical solution when you need to top off your tire pressure. While nitrogen offers potential benefits in terms of pressure retention and oxidation, the differences are often minimal for everyday driving. Prioritize maintaining proper tire pressure, regardless of the inflating gas, for optimal safety, handling, and tire longevity.