Fleet Maintenance - 16

der turning into a 3-cylinder engine. You're no
longer pumping that much air through the system
[and] you no longer have to combust that much
air at a low load or idle condition. The remaining
cylinders that are sweeping air can now be raised
to a slightly higher load, raising the temperature. That keeps the aftertreatment system hot,"
explains Robb Janak, director of new technology
for Jacobs Vehicle Systems. Known traditionally
for the development of its "Jake Brake" engine
brake, Jacobs Vehicle Systems develops and manufactures commercial vehicle retarding and valve
actuation technologies.
VVA technology can also offer additional engine
braking power, which is especially important at
a time when changes to vehicle design and function have improved the operating efficiency of the
vehicle. Aerodynamic fairings and body designs,
lower rolling resistance tires, coupled with a lower
engine displacement volume capacity (from 15L
to 13L, for instance) and downspeeding impact
the stopping distance of a heavy duty truck using
today's engine braking technology.
"We used to cruise at 1,400 or 1,500 rpm; now
we're down to 1,100 rpm," Dr. Dorobantu advises. "We're talking about, in the future, cruising at
1,000 rpm, or sub-1,000 rpm. That means fewer
and fewer engine compression strokes happening."
Jacobs Vehicle Systems has also been working to
address these concerns, with the development of the
company's High Power Density (HPD) engine brake.
"By having the HPD two-stroke engine brake,
that allows us to get that second compression
release with every revolution," explains Janak.
"You can improve the performance [of the engine
brake] at those lower engine speeds."
Making a business case for these technologies
can be the biggest hurdle to overcome as new
products are released to the market. This is why,
Dr. Dorobantu believes, it's important to have
multiple functionalities for a technology in order
to see the return on investment.
"CDA is mainly thought of as a NOx reduction
technology," Dr. Dorobantu says. "It's very hard
to put a price on NOx reduction. It's important
from a regulatory perspective, and from a societal
perspective. But from a freight efficiency perspective, NOx does not have an economic business case.
But, if the same CDA technology is also now part
of the high-capacity engine brakes which enable
significant CO2 reductions ... now there's a positive
economic value to the same CDA technology."
"We have invested our efforts to try to make
sure we have simultaneous CO2 and NOx reduction and that we can actually provide a positive
value proposition for the NOx reduction - making
fuel economy help pay for the NOx reduction technology," Dr. Dorobantu adds.

Possible updates to
the SCR system
The Cleaner Truck Initiative (CTI), a proposal for
rulemaking introduced in January of 2020, aims
to create regulations that will further reduce
NOx emissions beyond the previously set GHG
federal emissions standards, and establish separate standards from the current Phase 1 and
Phase 2 regulations.

16 Fleet Maintenance | February 2020

┬╗┬╗Cylinder deactivation (CDA) technology is
being developed and tested by a number of
industry groups, including Eaton and Jacobs
Vehicle Systems, to determine the viability
of improving engine efficiency. It works
through variable valve actuation, allowing
the valves to limit the number of cylinders
operating on an engine at a given time.

Considered a passive thermal management
strategy, a dual SCR system, also referred to as a
parallel SCR system, may help address this. Dual
SCR systems have the same design as a traditional
SCR catalyst, but an additional smaller SCR catalyst would be added to the aftertreatment system
upstream near the turbocharger exhaust. Because
of the closer proximity to the turbocharger, and
subsequently, the engine, the smaller SCR system
could heat up more quickly to allow diesel exhaust
fluid to be injected more readily once the engine
is initially started.
Experts are still working out the possibility of
implementing this technology. Current designs
may pose questions from a service perspective because the smaller SCR catalyst would be
upstream from the DOC and DPF.

New engine and
emissions system
technologies are
on the horizon.

What to expect, sooner
rather than later
Technologies fleets will see on late model trucks
will be higher compression ratios and methods to
improve combustion, such as component design
improvements to control the placement of fuel
during the combustion process, CDA, and lower
engine displacement volumes. Turbochargers may
become more readily implemented to provide
additional power in downspeeding applications
and at lower idling and cruising rpm. Changes
to the aftertreatment system will also ramp up.
"Initially, there will be many small changes to
improve friction, air management, and combustion efficiency," advises Paccar Vice President
Landon Sproull. Paccar is the parent company for
Kenworth, Peterbilt, and DAF trucks. "Advanced
controls and even deeper powertrain integration
will also provide benefits. Further out, increased
electrification of major engine systems, advanced
turbocharging concepts, and faster combustion
are other technologies OE's may turn to deliver
increased performance and economy."
"It will take more than one new technology to
meet future targets, but there is an industry-wide
push to increase fuel efficiency from the powertrain, chassis, and cab, along with the trailer," adds
John Moore, product marketing manager, Volvo
Trucks North America. "That will involve improvements such as faster ratios, more downspeeding,
idle reduction technology, improved aerodynamics between tractor and trailer, enhanced 6x2
technology, lighter-weight components, and low
rolling-resistance tires that meet demands for
traction and longevity."


Fleet Maintenance

Table of Contents for the Digital Edition of Fleet Maintenance

Vehicles: What's Next in Federal Vehicle Emissions Standards?
In the Bay: Technician Tool Support
Shop Operations: State of the Industry
Taking the Extra Step to Prevent Wheel-offs
Planning Ahead for Vehicle Cybersecurity Threats
Management: How Do You Know When to Replace a Vehicle?
Economic Outlook: Won't Get Fooled Again
Letter from the Editor: Real-world Views on Parts, Service, and Operations
Tools & Equipment
Guest Editorial: Moisture in Trailer Brakes is Not Just a Nuisance
Hand & Specialty Tools Supplement
Specialty Hand Tools: The Problem Solvers
Time to Multitask
Get a Hold on Hand Tool Safety
Electric Vehicle Tool Set
Tool Review
Fleet Maintenance - 1
Fleet Maintenance - 2
Fleet Maintenance - 3
Fleet Maintenance - 4
Fleet Maintenance - 5
Fleet Maintenance - 6
Fleet Maintenance - 7
Fleet Maintenance - 8
Fleet Maintenance - 9
Fleet Maintenance - Vehicles: What's Next in Federal Vehicle Emissions Standards?
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 - 20
Fleet Maintenance - 21
Fleet Maintenance - 22
Fleet Maintenance - 23
Fleet Maintenance - 24
Fleet Maintenance - 25
Fleet Maintenance - In the Bay: Technician Tool Support
Fleet Maintenance - 27
Fleet Maintenance - 28
Fleet Maintenance - 29
Fleet Maintenance - Shop Operations: State of the Industry
Fleet Maintenance - 31
Fleet Maintenance - 32
Fleet Maintenance - 33
Fleet Maintenance - 34
Fleet Maintenance - 35
Fleet Maintenance - 36
Fleet Maintenance - 37
Fleet Maintenance - Taking the Extra Step to Prevent Wheel-offs
Fleet Maintenance - 39
Fleet Maintenance - Planning Ahead for Vehicle Cybersecurity Threats
Fleet Maintenance - 41
Fleet Maintenance - 42
Fleet Maintenance - 43
Fleet Maintenance - Management: How Do You Know When to Replace a Vehicle?
Fleet Maintenance - 45
Fleet Maintenance - Economic Outlook: Won't Get Fooled Again
Fleet Maintenance - 47
Fleet Maintenance - Letter from the Editor: Real-world Views on Parts, Service, and Operations
Fleet Maintenance - 49
Fleet Maintenance - 50
Fleet Maintenance - Tools & Equipment
Fleet Maintenance - 52
Fleet Maintenance - Classifieds
Fleet Maintenance - Guest Editorial: Moisture in Trailer Brakes is Not Just a Nuisance
Fleet Maintenance - 55
Fleet Maintenance - 56
Fleet Maintenance - Hand & Specialty Tools Supplement
Fleet Maintenance - A2
Fleet Maintenance - Specialty Hand Tools: The Problem Solvers
Fleet Maintenance - A4
Fleet Maintenance - Time to Multitask
Fleet Maintenance - A6
Fleet Maintenance - Get a Hold on Hand Tool Safety
Fleet Maintenance - A8
Fleet Maintenance - Electric Vehicle Tool Set
Fleet Maintenance - Tool Review
Fleet Maintenance - A11
Fleet Maintenance - A12
Fleet Maintenance - Products
Fleet Maintenance - A14
Fleet Maintenance - A15
Fleet Maintenance - A16