Approximately 40% of all new trailers have tire pressure systems.
Tire pressure monitors track the pressure levels of tires using various sensor locations and indication methods. Having appropriate pressure reduces tire wear, increases fuel efficiency, and leads to fewer roadside breakdowns due to tire failures.
Correct tire inflation is a key component of fuel efficiency. Correct tire inflation also reduces the risk of on-road breakdowns and tire damage. However, about one in five trailers is operating with one or more tires underinflated by at least 20 psi.
Tire pressure monitoring systems (TPMS) are designed to avoid this problem and to let drivers know the inflation condition of trailer tires. They provide direct measurement of tire pressure. Measured pressure is compared to a pre-set target pressure to let the driver know when tires are underinflated.
Drivers get real-time notification of pressure loss, allowing them to add air to the tires before damage occurs.
The sensors tell the exact temperature and inflation pressure of the tire so drivers will know how serious the condition is.
Drivers know exactly which tire is underinflated and don’t have to walk around the truck trying to figure out where the problem tire is.
Tire pressure monitoring systems do not inflate an underinflated tire. They only inform the driver of underinflation.
TPMS may report false positives of underinflation.
Because the system does not correct underinflation, the driver must stop the vehicle to correct the underinflation.
Fleets are recognizing the value of properly-inflated tires and are realizing that having their drivers manually check tire pressure may not be the best option for ensuring appropriate tire pressure. This is especially true for trailer tires since trailers are not often mated to the same tractor and therefore drivers spend less time with any given trailer.
Private Fleet Study
A private carrier adopted TPMS on both its tractors and trailers. The primary motivation was to reduce emergency roadside calls and improve safety. The fleet selected TPMS because of its low acquisition cost and better payback relative to automatic tire inflation systems (ATIS). The fleet also was looking to engage its drivers in its efforts to properly maintain tires. The fleet places a high value on having data about tire condition. Beginning in 2007, the fleet began retrofitting its trailers with TPMS and is currently specifying them on all new trailer purchases. The fleet realized a 1.25% fuel economy improvement, an 8% increase in tire life, and a 9-month payback on the system.
A technology selection chart was developed that identified the major characteristics of the various tire pressure monitoring systems. The tool condenses an immense amount of information into a single matrix that can assist in the selection of the correct technology for the fleet.
The payback calculator allows fleets to input data and estimate the payback of various technologies based on their benefits. It calculates the benefits based on savings from reduced roadside breakdowns, extended tire wear, and improved fuel economy.
A growing number of customers are asking trailer manufacturers about tire pressure monitoring for trailers. Approximately 40% of all new trailers built have tire pressure systems. Trailer manufacturers said they are getting training in sales, assembly, and maintenance from system suppliers. Axles are being shipped already drilled and tapped to trailer assembly facilities to better accommodate integration of tire pressure systems on production lines.
Industry statistics show that 3% of all trailers operate with four or more tires underinflated by at least 20 psi, yet there is a 0.5% to 1.0% degradation of fuel economy for a vehicle running with all tires underinflated by 10 psi. This has caused fleets to focus more of their attention on proper tire maintenance, especially on trailers. 5-15% of new trailers equipped with tire pressure systems have TPMS.