Truck & Off-Highway Engineering - February 2022 - 8

TECHNICAL INNOVATIONS
DIESEL ENGINE DESIGN
Detroit DD15 Gen 5 showcases durability of new diesel tech
When Detroit launched the latest iteration
of the DD15 inline-six diesel engine
for on-highway applications, the company
promised a completely updated
unit that was engineered to deliver the
efficiency the market expects from a
heavy-duty engine platform in the Class
8 truck segment. Less than a year later,
the current generation of DD15 engines
have backed up the company's claim by
hitting the one-billion-mile mark of cumulative
field service.
" Reaching more than one billion
miles in less than one year of service is
not only an impressive milestone, but a
true testament to the performance of
the DD15 Gen 5 engine, " said Admir
Kreso, chief engineer, Daimler Truck
Powertrain. " Our customers have the
confidence to put the DD15 Gen 5 to the
test - with great success. "
The Gen 5 DD15 engine boasted sevRedesigned
components and new technologies
resulted in a 3% improvement in fuel efficiency
for the Detroit DD15 Gen 5 engine compared
to the previous generation.
Roughly 50% of the components for the DD15
Gen 5 were new or redesigned. Improved
electronic controls enabled a new feature
Detroit calls ThermoCoasting.
8 February 2022
eral new technologies and updated features
when it was launched in the first
quarter of 2021. The engine was
equipped with a new aftertreatment
system featuring improvements such as
thermo-management control. The new
system also trimmed 60 lb (27 kg) off
the weight from the previous iteration.
It achieved this weight loss in part by
deploying just one diesel particulate
filter (DPF) instead of two. The filter
utilizes asymmetric cell technology that
traps more particulates while maintaining
sufficient flow levels.
Improved electronic controls are another
enhancement, which enabled a new
feature Detroit calls ThermoCoasting.
According to Detroit, ThermoCoasting
prevents aftertreatment cool down during
regen to keep the system at the optimum
operating temperature. ThermoCoasting
will engage engine brakes, when necessary,
between 900 and 1,500 rpm while
the engine mimics coasting while simultaneously
maintaining zero torque at the
flywheel to balance power delivery.
Powertrain noise levels during
ThermoCoasting are reportedly minimal
and match decibel levels observed
when the engine is in the low engine
TRUCK & OFF-HIGHWAY ENGINEERING
BOTH IMAGES: DETROIT
Truck & Off-Highway Engineering - February 2022

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