EarthTalk: Is nitrogen better than air for filling car tires?
Nitrogen doesn’t leak out as quickly, and well-inflated tires save gas. But cost is also a factor.
Robert F. Bukaty/AP
Q: Is using nitrogen to inflate my car’s tires really better for the environment than using air? And if so, how?
– Roger Mawdsley, Abbotsville, BC
A: Whether or not it makes environmental sense to inflate car tires with nitrogen instead of air is a matter of much debate. Proponents of nitrogen say it is a smart choice primarily because it leaks from tires at a slower rate than air, so tires stay fully inflated longer. That, in turn, helps a vehicle attain better gas mileage. According to the Get Nitrogen Institute, a Denver-based nonprofit that advocates replacing the air in our tires with nitrogen, underinflated tires are a big contributor to global warming, as they cause drivers to waste fuel.
Although auto experts recommend checking your car’s tire pressure weekly, studies show that most drivers rarely if ever check to see if their tires are properly inflated and usually only add air when a tire is visibly low or beginning to go flat. A recent study by the European division of tiremaker Bridgestone found that 93.5 percent of cars in Europe have underinflated tires, wasting an estimated 2.14 billion gallons of costly, polluting fuel every year. Analysts believe that a similar percentage of North Americans are driving around on underinflated tires as well.
While properly inflated tires certainly promote better fuel efficiency and so are better for the environment, not everyone is persuaded that filling tires with nitrogen instead of plain ol’ air makes a difference.