Pros & Cons of TPMS for Class 3-8 Truck Tires
May 23, 2008
By Mike Antich
The U.S. Department of Transportation is expected to release its
revised medium-truck tire standard (FMVSS No. 119) during the second half of
the year. However, it is anticipated that it won’t contain a provision calling
for the use of a Tire Pressure Monitoring System (TPMS) for Class 3-8 commercial
trucks.
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 the
most common reasons for premature tire failures of truck tires is
underinflation. This is especially true with retreads, as the excessive heat
generated from underinflation will quickly break down a retread,” said David
Lodding, senior vice president, Donlen Fleet Management Services.
This is also the view of Bob Shipp, national truck sales manager
for Automotive Resources International (ARI). “You can see the results of
underinflated tires on the roadside every day (road gators). The inside tires
on dual rear tires are the most neglected tires on a vehicle, which causes wear
problems on the other tires,” said Shipp. “TPMS eliminates this problem.”
2. Fuel Savings: One
underinflated tire can cut fuel economy by 2-percent per pound of pressure
below the proper inflation level. “With today’s continual increases in fuel
costs, 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 without
having to check each tire,” said Dave Decker, manager of truck engineering for
Wheels Inc.
3.Extended Tire Life: A key advantage of TPMS is its ability to
reduce tire expense, the third-highest fleet expense. “Tire expense is right up
there with the cost of fuel and TPMS will extend tire life, lessen emergency
breakdown events, minimize crashes from tire failure, and increase fuel
economy. When you eliminate side wall damage, you increase the number of times
a tire can be retreaded. This is a saving for fleets,” said Shipp.
Echoing this assessment is Ken Gillies, manager, truck operations for GE
Capital Solutions Fleet Services. “TPMS allows for extended tire life, a positive
impact on fuel economy, lower maintenance costs, and high driver satisfaction
since less hands-on time for tires would be needed during the pre- and post-trip
inspection,” said Gillies.
Disadvantages of TPMS
Not everyone believes a TPMS mandate for commercial trucks is
needed. “I believe Class 3-8 trucks, as long as they are on a regular maintenance
schedule, need not make large investments in TPMS,” said Steve Byrd, CTP, regional
fleet services manager for PHH Arval’s truck services. “In fact, drivers of
most medium and heavy trucks are required to do a pre- and post-trip
inspection. During these inspections, the drivers will most likely be able to
identify underinflated tires. To assist drivers, a company may invest in a low-cost
solution such as a valve cap system. Yellow indicates low tire inflation and
red indicates a significantly low level of inflation. Any underinflated tire can
be identified during the pre- and post-trip inspections. Automated inflation
systems that draw air from a reservoir ($600-$800) may have more applicability
on tractors/trucks with super singles that carry heavy loads and traverse bridges
and highways where traffic essentially is not allowed to stop or pull over.”
One possible disadvantage of TPMS is that it may increase maintenance
expense. “This includes maintenance cost for the system itself and potentially
increased labor cost when performing work on the wheel ends for brakes, and
tire changes,” said Gillies.
Another potential disadvantage occurs during certain upfitting applications
when factory-installed wheels and tires need to be changed, such as with Hi-rail
systems. “How will the upfitter recalibrate the system for the new wheels and
tire?” said Decker.
Prospects of a Future TPMS Mandate
Some believe it is just a question of time before TPMS is mandated
for commercial trucks. With advances in wireless technology, some observers
predict that the TPMS mandate will be expanded to include Class 3-5 medium-duty
trucks by 2011 or 2012. These same observers go on to predict that several
years later, the TPMS mandate will be ultimately expanded to include Class 6
and 7 trucks. In the final analysis, a commercial truck TPMS mandate will benefit
the industry. “Any option that makes vehicles safer to operate is of great
value in our industry. Following the manufacturer’s suggested tire inflation
tables, coupled with proper alignment and suspension, is the easiest way to
increase overall tire life and, as a result, reduce tire replacement costs. I
would 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.
mike.antich@bobit.com