Comparison: nitrogen vs. oxygen in tires during cool weather

Cold weather brings us many things, some of them annoying - like the “low tire pressure" warning in our cars.

Chilly temperatures trigger a scientific magic trick by which air escapes from our all-season radials. And we don't see the results of this “abracadabra” until it's time to go to work on the first frosty morning of the season.

Some say filling tires with nitrogen is the solution – at a cost of anywhere from $3 to $20 per tire, depending on the vendor. With nitrogen, they say, your warning light is less likely to illuminate when the mercury suddenly drops.

The basic premise is nitrogen molecules are smaller than oxygen molecules and will escape through the rubber walls of your tires less rapidly.

Proponents, such as the Get Nitrogen Institute, say nitrogen promotes increased fuel economy, improved handling, and increased tire life.

“Nitrogen's larger size decreases the rate at which it permeates through the tire, keeping the tire correctly inflated for a longer time,” the institute says on its website. “It's not about the nitrogen, it's about reducing oxygen and moisture. Oxidation can damage the tire and it's components, as well as the wheel.”


Nitrogen fills the tires of around 27 million vehicles, according to the institute. A calculator on its website suggests nitrogen has saved more than two billion gallons of gasoline due to proper inflation.

But not everyone agrees.

The automotive experts at have posted a counter argument. Edmunds does not dispute much of the Institute’s claims, but it does caution consumers against paying a premium for nitrogen.


“Based on cost, convenience and actual performance benefit, we don't think nitrogen is worth it,” Edmunds wrote. “A much better use of your money would be to buy a good tire-pressure gauge and check your tires frequently.”

Some retailers, like Costco, fill tires with nitrogen at no additional cost.

So opt for nitrogen when it’s free, but when you are required to pay a premium for nitrogen, ask yourself whether the savings (time and money) are worth the price.