Nitrogen gaining popularity as efficient alternative to compressed air

By: MARK WALKER - Staff Writer | Saturday, October 22, 2005 9:00 PM PDT ∞

It makes up four-fifths of the Earth's atmosphere. It's a component of all proteins and nucleic acids. And for an increasing number of motorists, it's the stuff that keeps the tires inflated.

"It" is nitrogen, a tasteless and odorless gas that appears as No. 7 on the periodic table of chemical elements.

Nitrogen is emerging as an alternative to compressed air in automobile and truck tires because proponents say it leaks out at a much slower rate, keeps tire temperatures down, and doesn't contain the damaging moisture found in compressed air.

And all of that can improve gas mileage, something virtually all motorists are looking for as gas prices consistently hover at around $3 per gallon.

No, it doesn't explode, and yes, it can be mixed with compressed air.

The trend toward using nitrogen started about a year ago, and is gaining a foothold here and around the nation.

For a year now, every motorist who buys tires at Costco's 12 tire centers in San Diego and those in Southwest Riverside counties ---- as well as at all its stores across the nation ---- drives away on nitrogen-filled tread rather than compressed air, unless they ask for the traditional tire filler.

"We started offering it on all replacement tires because we thought it was a good idea to stabilize tire pressure and keep tire temperatures down," said Rob Lemay, Costco's San Diego regional tire center manager. "It's also good because compressed air has water molecules in it, and that will expand the tire pressure as temperatures rise."

Nitrogen is commonly used on commercial airliner tires, some long-haul trucks and in the tires of race cars.

The tipoff that tire contains nitrogen rather than compressed air is a green cap on the valve stem signifying its use.

The Rubber Manufacturers Association in Washington, D.C., doesn't have a formal position on nitrogen, but spokesman Dan Zielinski said the organization, which represents tire producers, agreed that it has advantages over compressed air.

"There's less diffusion through the tire walls and less moisture, which can help the overall life of the tire," he said. "We would not want people to get the impression that compressed air is unsafe, when the real issue is maintaining properly inflated tires."

Surveys conducted by the federal government and tire industry in recent years show that as many as 30 percent of all vehicles on the nation's roadways are driving on at least one under-inflated tire. The U.S. Department of Energy said that wastes about 4 million gallons of gasoline each day.

Many motorists do not routinely check their tire pressures, an exercise manufacturers recommend be done at least once a month. That may be changing as people look to improve their gas mileage, but for those who don't want to worry about it, or simply don't take the time, nitrogen may the best solution, according to Patrick Logue, director of marketing for Dunn Tire in Buffalo, N.Y.

"We put it in all our stores in January of this year, and charge $5 a tire to switch over from compressed air," he said. "For that customer who is conscientious and constantly checking their air pressure, nitrogen won't improve their mileage.

"But statistics say eight out of 10 people do not routinely check their air pressure, so nitrogen would be very helpful for that group."

At the Automobile Association of America's Los Angeles headquarters, spokesman Jeff Spring said the organization has not taken a position on nitrogen vs. compressed air, and has not tested it at its laboratory in Diamond Bar.

Not all of those who service tires are convinced of nitrogen's benefits.

At Goodyear Tire on El Norte Parkway in Escondido, service manager Mark Hahn said the store checked into nitrogen, but decided against it.

"None of us want to tamper with it," Hahn said. "While they say it slows down the loss of tire pressure, we don't think it does."

At Pep Boys, which has tested nitrogen at its stores in the Atlanta region and has 539 stores across the nation, spokesman Bill Furtkevic said about 20 percent of those who purchase tires through the stores are opting for nitrogen.

"We still have to do some analysis on the receptivity by consumers before we test it in other markets," he said.

When the question of whether nitrogen was the way to go was recently posed to Tom and Ray Magliozzi, the brothers whose popular "Car Talk" radio show is broadcast over National Public Radio stations each Saturday, they agreed that it has benefits, but questioned why anyone would pay to switch.

They agreed that nitrogen leaks out at a slower rate than compressed air, and agreed that it expands and contracts at a lesser rate under hot and cold temperatures.

But pay to switch?

"None of these advantages is important to the average driver," Ray Magliozzi said. "They just don't matter enough to ever think about. And they certainly don't matter enough to pay for."

Contact staff writer Mark Walker at (760) 740-3529 or mlwalker@nctimes.com.