Fleet Maintenance - 22

Proper specs are
integral to the
optimized performance
of a vehicle's engine.

VehicleServicePros.com/10121699

22 Fleet Maintenance | October 2019

in modern commercial vehicles," explains C. G.
(Lilo) Hurtado, applications engineer manager,
North America commercial diesel, ExxonMobil
Fuels and Lubricants. "The new fuel system has
provided better spray characteristics and more
precise control of fueling."
ExxonMobil is an international oil and gas
company serving multiple transportation sectors.
"Increased fuel injection pressure enables better
mixing of the fuel with the air in the cylinder,
resulting in better combustion and improved fuel
economy," adds Landon Sproull, vice president,
Paccar. Paccar is the parent company for Peterbilt
and Kenworth truck brands. "Some older high-pressure systems produced high fuel temperatures
due to inefficient compression processes, but new
engines put much less heat into the fuel. Return
fuel temperatures are now optimized to maintain
acceptable tank temperatures in the summer while
preventing fuel gelling in the winter."
A high-pressure fuel pump connected to the
engine pumps fuel at high pressures to deliver
the fuel to the fuel injectors at a steady rate. This
immense amount of pressure, and the temperature,
changes the composition of the diesel fuel from a
liquid to a gas. This process is known as atomization. Atomization allows the diesel to form smaller droplets to ensure the fuel is more efficiently
utilized during the injection process.
In addition to the injectors themselves, engine
manufacturers have made improvements on other
aspects of the system to help improve fuel efficiency,
says Kris Ptasznik, X15 product manager for heavy
duty engine manufacturer Cummins. "Injection spray
plume and spray angle are optimized in conjunction
with the piston bowl geometry and engine swirl to
ensure proper combustion while controlling emissions and maximizing fuel economy."
Brian Daniels, manager, Detroit powertrain and
component product marketing for Daimler Trucks
North America (DTNA) explains how the manufac-

» While improving fuel economy certainly
addresses environmental concerns and
government regulations, better fuel efficiency
also makes good business sense - because the
less fuel used, the more money a fleet will save.
Photo courtesy of Citgo

turer's proprietary Detroit DD15 engine utilizes a
type of HPCR system to optimize fuel usage, which
pressurizes the fuel at more than 30,000 psi.
DTNA is a heavy duty truck manufacturer,
producing Freightliner, Western Star, and Thomas
Built Buses nameplates.
"Higher temperatures have allowed us to
simplify the engine and remove the fuel heating
element, Daniels says. "Higher pressures have
also brought on increases in robustness of the
crankcase and block which helps improve overall
engine reliability."
HPCR systems communicate with the ECU and
are monitored through numerous sensors and
electronically controlled using solenoids and/or

» To maximize the fuel economy of
heavy duty trucks, it is important to
consider other specifications beyond the
powertrain, such as aerodynamic devices
and lower rolling resistance tires.
Photo courtesy of Cummins


http://www.VehicleServicePros.com/10121699

Fleet Maintenance

Table of Contents for the Digital Edition of Fleet Maintenance

Uptime: Are all systems secure?
Cover Story: Connecting to the future
Vehicles: Engine trends impacting performance and fuel efficiency
In the Bay: Understanding tire pressure monitoring and management systems
Shop Operations: How fleets can benefit from RCM
Management: Are you a good global citizen?
Economic Outlook: WDTKAWDTKI?
Powertrain: What are fault code action plans, and how can they help improve the vehicle diagnostic process?
Braking & Collision Avoidance: How will electric vehicles impact commercial truck braking systems?
Fleet Parts & Components
Tools & Equipment
Classifieds
Guest Editorial: Differences servicing air disc brakes versus drum brakes
Fleet Maintenance - 1
Fleet Maintenance - 2
Fleet Maintenance - 3
Fleet Maintenance - 4
Fleet Maintenance - 5
Fleet Maintenance - 6
Fleet Maintenance - 7
Fleet Maintenance - Uptime: Are all systems secure?
Fleet Maintenance - 9
Fleet Maintenance - Cover Story: Connecting to the future
Fleet Maintenance - 11
Fleet Maintenance - 12
Fleet Maintenance - 13
Fleet Maintenance - 14
Fleet Maintenance - 15
Fleet Maintenance - 16
Fleet Maintenance - 17
Fleet Maintenance - 18
Fleet Maintenance - 19
Fleet Maintenance - Vehicles: Engine trends impacting performance and fuel efficiency
Fleet Maintenance - 21
Fleet Maintenance - 22
Fleet Maintenance - 23
Fleet Maintenance - 24
Fleet Maintenance - 25
Fleet Maintenance - 26
Fleet Maintenance - 27
Fleet Maintenance - 28
Fleet Maintenance - 29
Fleet Maintenance - 30
Fleet Maintenance - 31
Fleet Maintenance - 32
Fleet Maintenance - 33
Fleet Maintenance - In the Bay: Understanding tire pressure monitoring and management systems
Fleet Maintenance - 35
Fleet Maintenance - 36
Fleet Maintenance - 37
Fleet Maintenance - 38
Fleet Maintenance - 39
Fleet Maintenance - 40
Fleet Maintenance - 41
Fleet Maintenance - 42
Fleet Maintenance - 43
Fleet Maintenance - Shop Operations: How fleets can benefit from RCM
Fleet Maintenance - 45
Fleet Maintenance - 46
Fleet Maintenance - 47
Fleet Maintenance - 48
Fleet Maintenance - 49
Fleet Maintenance - Management: Are you a good global citizen?
Fleet Maintenance - Economic Outlook: WDTKAWDTKI?
Fleet Maintenance - Powertrain: What are fault code action plans, and how can they help improve the vehicle diagnostic process?
Fleet Maintenance - 53
Fleet Maintenance - Braking & Collision Avoidance: How will electric vehicles impact commercial truck braking systems?
Fleet Maintenance - 55
Fleet Maintenance - Fleet Parts & Components
Fleet Maintenance - 57
Fleet Maintenance - 58
Fleet Maintenance - 59
Fleet Maintenance - 60
Fleet Maintenance - 61
Fleet Maintenance - Tools & Equipment
Fleet Maintenance - 63
Fleet Maintenance - 64
Fleet Maintenance - 65
Fleet Maintenance - 66
Fleet Maintenance - 67
Fleet Maintenance - 68
Fleet Maintenance - 69
Fleet Maintenance - 70
Fleet Maintenance - 71
Fleet Maintenance - 72
Fleet Maintenance - Classifieds
Fleet Maintenance - Guest Editorial: Differences servicing air disc brakes versus drum brakes
Fleet Maintenance - 75
Fleet Maintenance - 76
Fleet Maintenance - I1
Fleet Maintenance - I2
Fleet Maintenance - S1
Fleet Maintenance - S2
Fleet Maintenance - S3
Fleet Maintenance - S4
Fleet Maintenance - S5
Fleet Maintenance - S6
Fleet Maintenance - S7
Fleet Maintenance - S8
Fleet Maintenance - S9
Fleet Maintenance - S10
Fleet Maintenance - S11
Fleet Maintenance - S12
Fleet Maintenance - S13
Fleet Maintenance - S14
Fleet Maintenance - S15
Fleet Maintenance - S16
Fleet Maintenance - S17
Fleet Maintenance - S18
Fleet Maintenance - S19
Fleet Maintenance - S20
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