August 1, 2017 in Auto
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Nitrogen gas has been used for some time to inflate the tires of airplanes, racing cars and heavy-duty equipment. It is only recently that nitrogen has come into use for conventional vehicles.

Nitrogen is an odorless, colorless, non-toxic gas that makes up 78 percent of the Earth’s atmosphere. It is an inert (non-flammable) element, which means that it doesn’t readily react when mixed with other elements.

Nitrogen is often used in the tires of vehicles that operate in mines and other hazardous areas to reduce the risk of fire. It is typically used in off-highway vehicles where tires operate at their full load and are extremely stressed.

Benefits of nitrogen gas in tires

There are several benefits of using nitrogen in tires, whether it is in a pure or mixed form:

  • Increased fuel efficiency. Underinflated tires can reduce gas mileage. Since nitrogen reduces pressure at a slower rate than air, it helps tires to remain at the appropriate pounds per square inch (psi), thereby helping your car’s fuel efficiency.
  • Better tire-pressure retention. Tires have microscopic pores that allow any inflating gas, such as nitrogen and oxygen, to seep out over a long period of time, gradually reducing your tire pressure. Because nitrogen  molecules are larger than air molecules, it moves through the tire more slowly and maintains inflation pressure longer.

Consumer Reports found that using nitrogen in tires slightly improves tire-pressure retention, but it is not a substitute for regular inflation checks. Checking tire pressure regularly allows you to spot a pressure drop without paying the additional cost of using nitrogen.

  • Longer tire life. Because air is 78 percent nitrogen and 21 percent oxygen, it can retain moisture inside the tires and eventually oxidize the wall casings. This accelerates tire aging. Nitrogen, however, does not produce moisture because it’s an inert, dry gas. The use of 93 percent to 95 percent pure nitrogen helps prevent tires from aging and oxidizing caused by internal moisture.

Some experts, however, assert that under normal driving conditions, tire tread will reach its minimum depth for usability long before the effects of oxidation occur. Nitrogen in tires has only a minimal practical benefit under normal driving conditions.

Drawbacks of nitrogen in tires

Some of the major drawbacks of using nitrogen in tires include the cost, maintenance and availability. Air for tire inflation is available anywhere at a cheap price. Just about any tire dealer or service station will fill up your vehicle’s tires with air or allow you to make adjustments on your tire pressure, free of charge.

Nitrogen, however, is not yet widely available and typically costs $5 to $7 for filling each tire. Some nitrogen-equipped service centers charge $70 to $180 for a complete nitrogen upgrade. Upgrading your air-filled tires to nitrogen requires deflating and filling the tires with nitrogen a number of times until all of the air inside is purged. Keep in mind that the tires must be filled with 93 to 95 percent nitrogen to be safe and effective.

The bottom line

Whether or not using nitrogen in your tires will be worthwhile depends a lot on how you use your vehicle. Certainly, nitrogen could be beneficial if you have racing cars, collectible cars that are rarely driven, or need to store your vehicle for an extended period of time.

If you use your vehicle daily, however, it’s difficult to see how putting nitrogen in your tires gives you any practical and financial benefit, particularly compared with its availability.

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