Any tire expert will tell you that nitrogen filled tires help reduce air pressure loss and eliminate moisture that accompanies ambient air.
“One of the benefits of nitrogen is that it does not diffuse through the inner-liner of the tire as quickly as air,” said Greg Kidd, application engineer for Bridgestone Americas tire operations. “Therefore, nitrogen does reduce inflation pressure loss over time when compared with air.”
Airlines and race car teams that are particularly cautious about maintaining proper tire pressure have used nitrogen for years, but is this something that could be beneficial to truck fleets as well?
Over 10 years ago, you might have noticed several stories of fleets announcing thay’d signed up for nitrogen by acquiring machines that can render the common element from the air. In recent years, technology has continued to advance with improved tire pressure monitoring systems (TPMS) which have helped fleets to more consistently maintain ideal tire pressure on the road, something that seems to be more of a challenge for nitrogen users.
Some companies, such as Ryder System, have passed on the gas noting some of the downfalls. You see, once a truck hits the road with nitrogen-filled tires, those tires will need to be inflated with nitrogen while away from the home base in order to realize the benefits. Even small amounts of oxygen added to the mix can compromise the outcome.
“A nitrogen tire inflation program can be effective to aid tire performance if a 95% nitrogen saturation level inside the tire air chamber is maintained. Below this level, the program does not add benefits to a tire program,” said Ryder Director for National Tire Maintenance Elijah Williams. “Additionally, there is limited availability of nitrogen inflation stations and few providers who can support the program if a vehicle is outside of the Ryder network.”
The North American Council for Freight Efficiency (NACFE) has included nitrogen in its long list of fuel-saving practices, since, after all, properly inflated tires are proven to improve fuel economy. The agency’s latest report, however, did not indicate any fleets participating in the study use the gas.
“That’s been in our study forever and none of these fleets use it,” said NACFE executive director Mike Roeth, “but we keep hearing about it out in the field. We actually talked about taking it off but we decided to keep it on just in case, and so we keep asking the fleets year over year.”
The upfront cost of switching to nitrogen may also prove a deterrent for some fleets, with prices for commercial tire generators ranging from $8,000 to $15,000.
“The two primary disadvantages of nitrogen use are added cost and issues related to availability,” Kidd said.
He went on to note how much TPMS systems have come into play as of late to help fleets more consistently achieve ideal tire pressures.
“Certainly, TPMS systems have improved the monitoring and visibility of tire inflation pressure overall,” Kidd said. “A good inflation pressure maintenance program, coupled with a TPMS system, should yield positive results in maintaining consistent inflation pressure.”
Nitrogen could still make sense for some carriers, however, especially those with equipment that sits for long periods of time.
“We did a company outside of Pittsburgh two years ago that does lowboy hauling and those trailers sit and sit and sit,” said Frank Ruscitti, owner of NitrogenMan, a marketer of nitrogen generators for commercial fleets near Pittsburg, Pennsylvania. “Every time they went out West, they lost tires. It’s because those trailers sit and those tires deteriorate.”
“As trailers sit, any moisture that’s in that compressed air sits in the bottom of that tire and it eventually permeates into the rubber,” Ruscitti said, “and then – when you have oxygen with heat – you get oxidation. So normally when tires blow, they blow at that weak point where that moisture was.”
Kidd added that since nitrogen cuts out moisture, it can also benefit sensitive TPMS electronics.
“It is important to note that nitrogen inflation utilizes dry inflation, where air inflation typically contains water and water vapor,” Kidd explained. “The presence of water in air-inflated tires can have a negative effect on TPMS sensors, potentially causing them to report inaccurate readings or fail prematurely. Thus, it is important for fleets to maintain dry air when using air inflation.”
When nitrogen is not an option, Kidd explains that moisture can be purged “by utilizing a dependable dryer near the compressor output, as well as a drain or some type of moisture-removing device at each airline drop within the shop.”
This method is more likely to be used by fleets t this time, given the higher upfront cost of switching to nitrogen.
“I am not aware of a trucking fleet in North America that is utilizing nitrogen inflation,” Kidd said. “It’s mostly typically used in aircraft and racing tires, and occasionally in off-road tires.”