About 1 out of 5 tractors/trucks is operating with one or more tire underinflated by at least 20 psi.
Federal Motor Carrier Safety Administration
Proper tire inflation pressure is critical to the proper operation of a commercial vehicle. Correct tire inflation reduces tire wear, increases fuel efficiency, and leads to fewer roadside breakdowns due to tire failures. However, only 46% of all inspected tractor tires are within ±5 psi of the desired target pressure. A tire pressure monitoring system can help with diagnosing this problem sooner for quicker correction.
Tire pressure monitoring systems (TPMS) track the pressure levels of tires using various sensor locations and indication methods. Tire pressure monitoring systems are designed to let drivers know the inflation condition of each tractor tire. They provide direct measurement of tire pressure and compare the measured pressure to a pre-set target pressure to let drivers know when tires are underinflated.
Adoption rate of these systems on tractor is still relatively small.
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.
The system may report false positives of underinflation.
The payback for TPMS on tractors may not currently be sufficient to justify wide-scale adoption given the initial cost of the system.
Because the system does not correct underinflation, the driver must stop the vehicle to correct the underinflation.
The value of appropriate tire pressure is significant, especially given high fuel prices. Fleets are realizing that having their drivers manually check tire pressure may not be the best option for ensuring appropriate tire pressure.
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. In 2011, the fleet decided to purchase TPMS on all new tractors. The calculated payback for the tractor systems was 13.74 months and a 0.75% fuel economy improvement and a 4% improvement in tire life were predicted. The fleet has not conducted fuel efficiency testing at this point.
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.
Truck manufacturers indicate that fleets are doing a better job of maintaining proper tire inflation on tractors than on trailers without the use of tire pressure systems. One tire pressure monitoring system is production-available at three truck manufacturers, but there has been limited adoption. Other manufacturers’ products are available for installation at upfitters or dealerships prior to delivery. Truck manufacturers believe that system payback is not attractive enough to encourage adoption. Truck builders indicated they would be willing to engineer various TPMS into their tractors if there was a reasonable order volume. Some truck manufacturers are studying whether it makes sense to offer these systems as part of their regular truck production.
The ability to know the actual tire pressure by wheel position and to capitalize on the data transmission capability of electronic sensors and on-board systems are key advantages of TPMS over ATIS. Private fleets are more likely to choose TPMS and actively engage their drivers in proper tire maintenance procedures.