By Mike Antich
The U.S. Department of Transportation is expected to release itsrevised medium-truck tire standard (FMVSS No. 119) during the second half ofthe year. However, it is anticipated that it won’t contain a provision callingfor the use of a Tire Pressure Monitoring System (TPMS) for Class 3-8 commercialtrucks.
TPMS is an electronic system that monitors the air pressure inside pneumatic tires. Should TPMS be mandated for commercial trucks over 10,000 lbs.? Here are three reasons supporting this.
1. Safety: “One of themost common reasons for premature tire failures of truck tires isunderinflation. This is especially true with retreads, as the excessive heatgenerated from underinflation will quickly break down a retread,” said DavidLodding, senior vice president, Donlen Fleet Management Services.
This is also the view of Bob Shipp, national truck sales managerfor Automotive Resources International (ARI). “You can see the results ofunderinflated tires on the roadside every day (road gators). The inside tireson dual rear tires are the most neglected tires on a vehicle, which causes wearproblems on the other tires,” said Shipp. “TPMS eliminates this problem.”
2. Fuel Savings: Oneunderinflated tire can cut fuel economy by 2-percent per pound of pressurebelow the proper inflation level. “With today’s continual increases in fuelcosts, fleets are looking for any advantage to get better fuel economy. With TPMS,a driver will have the advantage of knowing when tire pressure is low withouthaving to check each tire,” said Dave Decker, manager of truck engineering forWheels Inc.
3.Extended Tire Life: A key advantage of TPMS is its ability toreduce tire expense, the third-highest fleet expense. “Tire expense is right upthere with the cost of fuel and TPMS will extend tire life, lessen emergencybreakdown events, minimize crashes from tire failure, and increase fueleconomy. When you eliminate side wall damage, you increase the number of timesa tire can be retreaded. This is a saving for fleets,” said Shipp.
Echoing this assessment is Ken Gillies, manager, truck operations for GECapital Solutions Fleet Services. “TPMS allows for extended tire life, a positiveimpact on fuel economy, lower maintenance costs, and high driver satisfactionsince less hands-on time for tires would be needed during the pre- and post-tripinspection,” said Gillies.
Disadvantages of TPMS
Not everyone believes a TPMS mandate for commercial trucks isneeded. “I believe Class 3-8 trucks, as long as they are on a regular maintenanceschedule, need not make large investments in TPMS,” said Steve Byrd, CTP, regionalfleet services manager for PHH Arval’s truck services. “In fact, drivers ofmost medium and heavy trucks are required to do a pre- and post-tripinspection. During these inspections, the drivers will most likely be able toidentify underinflated tires. To assist drivers, a company may invest in a low-costsolution such as a valve cap system. Yellow indicates low tire inflation andred indicates a significantly low level of inflation. Any underinflated tire canbe identified during the pre- and post-trip inspections. Automated inflationsystems that draw air from a reservoir ($600-$800) may have more applicabilityon tractors/trucks with super singles that carry heavy loads and traverse bridgesand highways where traffic essentially is not allowed to stop or pull over.”
One possible disadvantage of TPMS is that it may increase maintenanceexpense. “This includes maintenance cost for the system itself and potentiallyincreased labor cost when performing work on the wheel ends for brakes, andtire changes,” said Gillies.
Another potential disadvantage occurs during certain upfitting applicationswhen factory-installed wheels and tires need to be changed, such as with Hi-railsystems. “How will the upfitter recalibrate the system for the new wheels andtire?” said Decker.
Prospects of a Future TPMS Mandate
Some believe it is just a question of time before TPMS is mandatedfor commercial trucks. With advances in wireless technology, some observerspredict that the TPMS mandate will be expanded to include Class 3-5 medium-dutytrucks by 2011 or 2012. These same observers go on to predict that severalyears later, the TPMS mandate will be ultimately expanded to include Class 6and 7 trucks. In the final analysis, a commercial truck TPMS mandate will benefitthe industry. “Any option that makes vehicles safer to operate is of greatvalue in our industry. Following the manufacturer’s suggested tire inflationtables, coupled with proper alignment and suspension, is the easiest way toincrease overall tire life and, as a result, reduce tire replacement costs. Iwould look at a future mandate for TPMS as a plus for the industry,” said Bill Byron,senior truck specialist-medium/heavy duty for Donlen Corp.
Let me know what you think.