More and more tire stores and auto dealerships are proposing that filling your tires with nitrogen will save you money on gas while offering better performance than air. But is that really true? Closer inspection uncovers some practical realities about using nitrogen to fill your tires: It has few benefits and significantly higher costs. How much higher? Anywhere from $3-$10 on average.
But why even consider Nitrogen for tires?
- Better tire-pressure retention: On a monthly basis, tires gradually lose about 1 pound per square inch (psi) of pressure. Changes in temperature will accelerate this. The general rule of thumb is a loss of 1 psi for every 10-degree rise or fall in temperature. The GNI states that because nitrogen has larger molecules…it leaks less from the tire walls and produces more stability in tire pressure. Consumer Reports did a year-long study (2006) to determine which was really better for tires…nitrogen or air. Bottom line: Nitrogen won the contest, but only by a slim margin.
- Improved Fuel Economy: The EPA says that under-inflated tires can lower gas mileage by 0.3 percent for every 1 psi drop in pressure of all four tires. The theory is that since nitrogen loses pressure at a slower rate than air, you are more likely to be at the correct psi and therefore get better fuel economy.
If you’re proactive and check your tire pressure at least once a month, you can offset this difference with free air, and you won’t need expensive nitrogen. We think this invalidates the “better fuel economy with nitrogen” argument. – Edmunds
- Cost and Convenience: The reality…Nitrogen is rarely free…maybe at Costco and at a limited number of car dealerships. Otherwise…prices for filling a tire with nitrogen can range from $5-$7 per tire. If you could muster up the diligence to check your tires monthly…you could potentially save roughly $80 a year on nitrogen alone per tire. At most gas stations…air is still somwhere between free or $.75-cents to fill-up all four of your tires.
Bottom Line Nitrogen Value Proposition?
Considering cost, convenience and actual performance benefits…nitrogen is probably NOT worth the effort. You’d be better off spending a few bucks on a quality tire-pressure gauge and checking your tires frequently.