18 Fleet Maintenance | AUGUST 2017
Owners and operators of trucks powered by
the more complex EPA-compliant heavy duty
diesel engines experienced a number of problems
with these engines. Among them, a high rate of
engine- and fuel-related problems, resulting in
unplanned downtime. Th e problems were caused
by the technology that was designed to reduce
emissions from heavy duty truck engines.
In August 2011, U.S. EPA and the National
Highway Traffi c Safety Administration (NHTSA)
issued their Phase 1 Greenhouse Gas Emissions
Standards and Fuel Effi ciency Standards for
Medium and Heavy Duty Engines and Vehicles.
The agencies said these standards were
designed to “improve fuel effi ciency and cut
carbon pollution to reduce the impacts of climate
change, while bolstering energy security and
spurring manufacturing innovation.” Th e standards
aff ected model years 2014 to 2018.
In August 2016, the two agencies issued the
Greenhouse Gas Emissions and Fuel Effi ciency
Standards for Medium and Heavy Duty Engines
and Vehicles — Phase 2. It would “promote a new
generation of cleaner, more fuel effi cient trucks
by encouraging the development and deployment
of new and advanced cost-eff ective technologies,”
said EPA and NHTSA.
Th e vehicle and engine performance standards
cover model years 2021 to 2027 for semi-trucks,
large pickup trucks, vans and all types and sizes
of buses and work trucks. Th e standards are being
rolled out in three stages: 2021, 2024 and 2027.
EPA and NHTSA standards also cover model
years 2018 to 2027 for certain trailers. Th is is the
fi rst time trailer OEMs have been regulated by
the U.S. EPA.
Up to the Challenge
How is the industry meeting these objectives
in such a compressed period of time? Th rough
innovation.
Take PACCAR, for example.
PACCAR is a premier diesel
engine manufacturer and
global technology leader in
the design, manufacture and
customer support of light,
medium and heavy duty
trucks under the Kenworth,
Peterbilt and DAF nameplates.
Meeting the vehicle and
engine performance standards
“involves the use of
materials and components that provide the right
combination of strength and weight; advanced
engine control technology; and a commitment
to making the refi nements necessary to exceed
customer expectations,” says Landon Sproull, vice
president, powertrain, PACCAR (www.paccarpowertrain.
com).
Diesel Engine Evolution
“SCR (Selective Catalyst Reduction) in conjunction
with a DPF (diesel particulate fi lter) has become the
established aft ertreatment technology for meeting
U.S. EPA and NTHSA emissions standards,” says
PACCAR’s Sproull. “More than 500,000 vehicles in
the industry are successfully performing with SCR
and DPF technology today.
“Regulated emissions have been reduced to nearzero
levels with no visible smoke emitted from the
engine. A white handkerchief will stay white when
held over the exhaust pipe.”
Advanced electronic control technology provides
more precise combustion timing, reduced emissions
and better fuel economy, he points out. A smart
engine and emission control system can communicate
real-time performance and diagnostic information
to the customer and dealer effi ciently and
in simple language.
“One of the most important developments in the
North American engine market is the ability to
produce more power and performance from a smaller
displacement engine,” notes Sproull. “Engines
with smaller displacements can provide power and
torque that are comparable to larger engines, with
the added benefi ts of less weight, better fuel economy
and reduced emissions.”
Sproull adds that engine life is increasing. A B50
engine — once an industry standard for average
life to overhaul — meant that at 1 million miles,
50 percent of the engines would need a rebuild. In
2010, PACCAR’s MX engine platform was designed
with a B10 life, meaning that 90 percent of these
engines will go beyond 1 million miles without the
need for a major overhaul.
Th e advantages of proprietary engines have
enabled truck OEMs, like Peterbilt and Kenworth, to
better integrate the engine to the vehicle. An example
of this collaborative approach is easier access to
preventive maintenance items on the truck, like oil
and fuel fi lters.
“Industry-leading serviceability of PACCAR
engines and trucks is achieved through intense
design collaboration of PACCAR engineers and
dealer and customer technicians,” Sproull says.
Through technological innovation achieved by
collaboration between the U.S. DOE, national labs,
universities, and the private sector, engine manufacturers
have been able to implement a variety
of state-of-the-art technologies that ensure diesel
engines are running cleanly and efficiently.
More to Come
To be sure, heavy duty diesel engine research and
development to increase understanding of the
combustion process and emissions will continue,
and this will lead to more technological innovation.
In turn, this will help develop even cleaner and
more effi cient engines and promote national goals,
such as protecting public health and promoting energy
security.
» Landon Sproull,
PACCAR
Emissions have
driven change.
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