Nitrogen vs. Air in Tires: Is Nitrogen Better?

If you've ever bought new tires or visited a dealership, you may have been asked whether you want your tires filled with nitrogen instead of regular air. That raises a common question: Is nitrogen better than air in tires?

For most everyday drivers, regular compressed air works perfectly well when tires are properly maintained. Nitrogen does, however, offer some advantages, including a drier inflation gas and somewhat slower pressure loss over time.

Those benefits can be particularly useful for tire shops, dealerships, commercial fleets, racing applications, and other facilities that regularly service tires.

Here's what you should know when comparing nitrogen vs. air in tires.

Nitrogen vs. Air in Tires: What's the Difference?

Regular air is already approximately 78% nitrogen. The remainder is primarily oxygen, along with small amounts of other gases and potentially water vapor.

Nitrogen tire inflation increases the concentration of nitrogen inside the tire while reducing oxygen and moisture.

The biggest practical difference isn't that nitrogen behaves completely differently from air. Instead, nitrogen provides a dry, more concentrated inflation gas that can help tires maintain pressure somewhat longer.

What Are the Benefits of Nitrogen in Tires?

1. Slower Tire Pressure Loss

All tires gradually lose pressure over time. Nitrogen can escape through tire rubber more slowly than oxygen, which can help nitrogen-filled tires maintain their pressure somewhat longer.

That doesn't mean nitrogen-filled tires never lose pressure. Punctures, leaking valve stems, damaged wheels, temperature changes, and normal leakage can still cause tire pressure to drop.

2. Less Moisture Inside the Tire

One advantage of nitrogen is that properly generated nitrogen is dry.

Compressed shop air can contain moisture unless the facility has adequate air-drying and filtration equipment. Reducing moisture can be useful in applications where consistent inflation conditions are especially important.

3. More Consistent Inflation Conditions

Because nitrogen inflation provides a dry gas with a high nitrogen concentration, it can provide more consistent inflation conditions. This is one reason nitrogen is commonly used in demanding or high-volume applications such as:

• Automotive dealerships
• Tire shops
• Commercial truck fleets
• Fleet maintenance facilities
• Racing and performance vehicles
• Specialty vehicles

Does Nitrogen Improve Gas Mileage?

Not automatically.

Proper tire pressure can affect fuel economy, but simply putting nitrogen into a tire doesn't guarantee improved gas mileage. The real benefit comes from keeping tires properly inflated.

If nitrogen helps a tire maintain its recommended pressure longer, it may indirectly help maintain proper rolling resistance. However, a properly maintained tire filled with regular air can accomplish the same goal.

Does Nitrogen Make Tires Last Longer?

Nitrogen itself shouldn't be viewed as a guaranteed way to dramatically increase tire life. Maintaining the correct tire pressure is far more important.

Underinflated tires can increase heat buildup and contribute to improper tread wear. Overinflation can also negatively affect tire performance and wear.

Regardless of what's inside the tire, proper inflation, tire rotation, wheel alignment, and regular inspections remain important for maximizing tire life.

Does Nitrogen Tire Pressure Change With Temperature?

Yes. A common misconception is that nitrogen-filled tires don't change pressure when temperatures rise or fall.

Both nitrogen and regular air respond to temperature changes. When temperatures fall, tire pressure generally falls. When temperatures increase, tire pressure generally increases.

Nitrogen does not eliminate temperature-related tire pressure changes.

Do Nitrogen-Filled Tires Still Need Their Pressure Checked?

Yes. You should still regularly check the pressure of nitrogen-filled tires.

The National Highway Traffic Safety Administration recommends checking tire pressure at least once a month when the tires are cold. The correct PSI can generally be found on the vehicle's tire information label or in the owner's manual.

Don't use the maximum PSI printed on the tire sidewall as your vehicle's recommended inflation pressure.

Whether you're using nitrogen or air, maintaining the vehicle manufacturer's recommended tire pressure is what matters most.

Can You Put Regular Air in a Tire Filled With Nitrogen?

Yes.

If your nitrogen-filled tire is low and you don't have access to nitrogen, add regular compressed air rather than driving with an underinflated tire.

Mixing air with nitrogen simply reduces the percentage of nitrogen inside the tire. You can have the tire serviced with nitrogen again later if you want to restore a higher nitrogen concentration.

Nitrogen vs. Air in Tires: Pros and Cons

Is Nitrogen Worth It for Your Tires?

For the typical passenger vehicle, nitrogen isn't a necessity. If you're diligent about checking your tire pressure and maintaining your vehicle, compressed air works just fine.

Nitrogen becomes more attractive when consistency, moisture reduction, high tire-service volume, or fleet maintenance is important.

That's why the value of nitrogen can be different for an individual driver compared with an automotive business. A driver may only have four tires to maintain, while a tire dealer, dealership, repair shop, or fleet facility may service hundreds or thousands of tires.

Why Do Tire Shops Use Nitrogen?

Professional tire shops can offer nitrogen inflation as an additional tire service. Instead of relying solely on nitrogen cylinders, shops can use a nitrogen generator and tire inflator to produce nitrogen on-site.

A professional nitrogen generation system connects to the shop's compressed air supply and separates nitrogen from the incoming air. The generated nitrogen can then be used for tire inflation.

Depending on the equipment, shops may be able to:

• Inflate multiple tires simultaneously
• Automatically purge and refill tires
• Set desired tire pressure
• Perform nitrogen top-offs
• Convert air-filled tires to a higher nitrogen concentration
• Service passenger vehicles, light trucks, and commercial vehicles

What Is a Nitrogen Tire Inflator?

A nitrogen tire inflator is professional automotive equipment used to deliver nitrogen to vehicle tires.

Some machines combine the inflator with an integrated nitrogen generator, allowing the shop to produce nitrogen from its existing compressed air system and inflate tires using the same piece of equipment.

For shops offering nitrogen tire service regularly, this can reduce the inconvenience associated with storing, replacing, and managing nitrogen cylinders.

NitroFill Nitrogen Tire Inflators & Generators

For automotive businesses interested in offering nitrogen tire service, NitroFill manufactures professional nitrogen generation and tire inflation equipment for automotive and commercial applications.

NitroFill offers systems for different service volumes and vehicle types, ranging from passenger vehicle applications to higher-volume commercial and fleet operations.

Depending on the model, NitroFill systems can provide features such as high-purity nitrogen generation, automatic tire inflation, multi-tire service, programmable pressure settings, and higher-output nitrogen production.

For shops already equipped with compressed air, a NitroFill nitrogen generator can provide an on-demand source of nitrogen directly in the service bay.

Shop NitroFill Nitrogen Tire Inflators & Generators

Frequently Asked Questions About Nitrogen in Tires

Is nitrogen better than air in tires?

Nitrogen offers some advantages, including reduced moisture and somewhat slower pressure loss. However, properly maintained compressed air is suitable for most passenger vehicles.

Can you mix nitrogen and air in tires?

Yes. Adding regular air to a nitrogen-filled tire is safe. Maintaining the correct tire pressure is more important than maintaining a specific nitrogen concentration.

How can you tell if a tire has nitrogen?

Nitrogen-filled tires sometimes have green valve-stem caps, although a green cap doesn't guarantee that the tire currently contains a high concentration of nitrogen.

Do nitrogen tires lose pressure?

Yes. Nitrogen-filled tires can still lose pressure from normal permeation, punctures, leaking valves, damaged wheels, and other causes.

Does nitrogen tire pressure change in cold weather?

Yes. Nitrogen tire pressure still changes as temperatures change. Nitrogen does not eliminate pressure changes caused by colder or warmer temperatures.

How often should you check nitrogen-filled tires?

Nitrogen-filled tires should still be checked regularly. NHTSA recommends checking tire pressure at least monthly when the tires are cold.

Can I put air in my nitrogen tires?

Yes. If your tire is underinflated and nitrogen isn't available, adding regular air is preferable to driving on an underinflated tire.

Do you need special equipment to fill tires with nitrogen?

Consumers can have nitrogen added at a facility offering nitrogen tire service. Automotive businesses that want to provide nitrogen inflation can use a nitrogen generator and tire inflation system to generate nitrogen from compressed shop air.

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