Nitrogen versus Air in your Tires
Tires are designed and built to provide many miles of reliable service but must be properly maintained for them to do so. The key element of proper tire maintenance is proper tire inflation. The recommended tire pressures actually originate from the vehicle manufacturer and not the tire companies. To find your vehicle’s recommended tire pressures, you should look on the vehicle’s tire placard which is on the door post or the edge of the driver’s side door. Another place to look is in the owner’s manual, on the inside of the glove box door or sometimes inside the fuel door. General Tire recommends that the consumer check his/her tire inflation pressures at regular intervals of at least once per month and before every long trip.
All gasses expand when heated and contract when cooled. Tire inflation pressures are no different. They can rise and fall with changes in ambient temps by on psi (pounds per square inch) for every 10 degrees Fahrenheit. Therefore, it’s recommended that you check your pressures early in the morning before the sun heats up your tires or prior to heat generated by driving which also causes the pressures to rise.
So Nitrogen or regular old Air?
If you’re confused about which to use in your tires , don’t panic – you’re not alone. The cacophony of claims in the war between air and nitrogen runs the gamut from nitrogen being the greatest technological advance since someone figured out how to use a wheel, to the use of nitrogen being a complete sham.
The truth of the matter is that nitrogen does have some scientific advantages over air, but they lie at the upper reaches of the tire performance spectrum, and it’s debatable if the average driver will reap any benefits from using nitrogen. For normal everyday consumer tire service applications, nitrogen tire inflation is not required. In the purest form, nitrogen has been used primarily because it doesn’t support moisture or combustion. Nitrogen is an inert (non-flammable) gas – nothing more than dry air with the oxygen removed. Ambient air contains usually 78% nitrogen, 21% oxygen and 1 % miscellaneous gas. Because of nitrogen’s inert properties, it is often used in highly specialized tire service applications and/or demanding environments. These applications usually include aircraft, mining, and commercial/heavy use. Also, nitrogen is used in professional auto racing where extreme vehicle speeds are involved. Dry nitrogen is used in this regard to help reduce tire pressure variations where the smallest differences in pressures can have a negative effect on race vehicle handling at the extreme limits of performance.
For normal everyday consumer tire service applications, nitrogen tire inflation is not required or overly beneficial. Air for tire inflation is almost universally available at a reasonable cost. Just about any service station or tire dealer anywhere will fill up your tires or let you adjust your tire pressure for free, or for a couple of dollars at the most. Not so with nitrogen. The infrastructure for nitrogen is not fully developed and, in many places, nitrogen is simply not available. Where it is available, nitrogen generally costs $5 – $7 for filling each tire, and some tire installers will charge $70-$180 for a complete nitrogen upgrade. Converting air-filled tires to nitrogen requires filling and deflating the tires with nitrogen several times to purge all the air (nitrogen must be 93-95% pure to be effective).
If you have nitrogen-filled tires and you encounter a tire deflation issue on the road where no nitrogen is available, you can top up the tire with air with no ill effects to the tire or your vehicle’s handling, but you may have to recharge the tire with nitrogen later to purge the air.
There’s nothing wrong with keeping your tires inflated with air. After all, drivers have been using compressed air successfully for years! Compressed air is east to find and often free. Depending on where you go, it could also cost more and take longer for your tires to be inflated with nitrogen (especially the first time). When it comes to convenience and cost, compressed air is the clear winner.