Detroit DD15 Engine

Taking Innovation and Efficiency to a New Level

Our engineers continue to refine and improve many features of the Detroit® DD15® to reach a new level of performance and efficiency.

Brochures and Videos Maintenance Intervals and Warranties

1550-1750 lb-ft

Torque Range

400-505 HP




Our engineers re-examined, then re-designed many features of the DD15 to reach this level of performance

*Includes 400/1750 rating exclusively in the Integrated Detroit Powertrain

More Specs


  • A three-stage integrated Jacobs® engine brake for quieter engine braking and superior braking power
  • A robust rear gear train
  • A cooling system with shorter fan-on times for increased fuel efficiency
  • A proprietary asymmetric turbocharger to improve performance
  • An Amplified Common Rail System (ACRS™) to optimize combustion control
  • 2017 Greenhouse Gas (GHG17) and 2016 OBD (OBD16) compliance 
  • A proprietary asymmetric turbocharger, optimally matched to the updated Exhaust Gas Recirculation (EGR) system, delivering outstanding performance
  • An Amplified Common Rail System (ACRS) to optimize combustion control
  • Optimized piston design for reduced friction and improved engine performance and durability
  • A variable-speed water pump that utilizes a viscous clutch between the pulley and impeller drive to reduce impeller speeds, making it more efficient than a gear-driven design
  • 2017 Greenhouse Gas (GHG17) and 2016 OBD (OBD16) compliance


Custom-configure your Freightliner Cascadia® with the performance-packed, reliable, fuel-efficient DD15 engine, only from Detroit.


Model Options

Designed for construction, distribution, dump, fire and emergency, government, motor home, oil & gas, refuse, and regional.

Western Star
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Detroit Connect Virtual Technician remote diagnostic system

If maintenance issues come up while on the road, you can count on Detroit Connect Virtual Technician. With Virtual Technician, you are notified within minutes when your vehicles experience a fault event, the severity of the fault and when, where and how to best fix the issue causing the fault so you can make informed service decisions.

Keep running

With the longest service intervals in its class and an easily serviceable design, the Detroit DD15 lowers your cost of ownership by decreasing your time in the shop. With oil and fuel filters positioned above the frame rails, you'll be back in the driver's seat fast.

Integrated Detroit Powertrain


The Integrated Detroit Powertrain delivers the performance and dependability you need to run your business efficiently. Detroit has designed, engineered and manufactured the engine, transmission and axles to work together seamlessly, providing the optimal powertrain solution for your business needs. The Integrated Detroit Powertrain is available in the Freightliner Cascadia.


  • 2017 Greenhouse Gas-Compliant Engines: The flagship DD13® and DD15® engines are compliant 2017 Greenhouse Gas (GHG17) standards.
  • Downsped Engines = Improved Fuel Economy: The DD13® and DD15® with downsped 400 HP and 1750 lb/ft rating deliver greater horsepower and torque at lower RPMs, keeping your truck in top gear longer while cruising at more efficient engine speeds. Lower engine speeds reduce the number of fuel injections, dramatically improving fuel economy.
  • Six-Blade Engine Fan: The six-blade fan reduces power draw without sacrificing cooling capabilities.


  • Integrated Communications Benefits: The DT12® transmission links engine to axles, and communicates with the DD13® and DD15® on an integrated electronics network to share damage-reducing information such as clutch overloading and driveline protection.
  • Super-Finished Gears: Tightly-spaced 12-speed gearing, now with "super-finished" gears in the new DT12® available for the new Cascadia, improves low-speed maneuverability, making the Detroit® Powertrain not only strong and efficient, but also smooth and safe to operate as well.
  • Intelligent Powertrain Management (IPM): The DT12® uses information from a topographical map to manipulate both engine and transmission functions, taking advantage of the truck's surroundings. IPM4 refines the parameters of this technology, making the truck even more capable of utilizing its surroundings efficiently.
  • Transmission Benefits: The DT12's direct drive and over drive gearing, along with eCoast, are integrated with the downsped engine — which now idles at a lower 500RPM when off-throttle — for optimized fuel economy.


Steer Axle

  • Numerous Steer Axle Advantages: Detroit® steer axles offer rugged strength in a lightweight package, and integrate optimally with the other components. They are designed for the life of the axle, with multiple ratings available for tailored weight distribution.
  • Superior Maneuverability: The Detroit® Powertrain's state-of-the-art steer axles provide a 55-degree wheel cut for remarkably nimble maneuvering. 
  • Needle Bearings Improve Durability: With needle bearings instead of bushings, they won't damage the king pins, and offer increased durability.

Tandem Rear Axle

  • New Axles Designed for Fuel Economy: To provide optimum efficiency and performance, the Detroit Powertrain includes an all-new axle specifically designed to integrate with the downsped DD13®, DD15® and DT12®, resulting in rock-solid reliability and durability.
  • Faster 6x4 Axle Ratios: The 6x4 configuration is available for applications requiring 4-wheel drive and superior traction. A variety of faster axle ratios are available, ranging from 2.41 to 2.28.
  • Faster 6x2 Axle Ratios: The 6x2 configuration boasts a 2.28 ratio, allowing the DD15 to turn lower RPMs with the truck cruising at the same speed. It pairs perfectly with the low RPM torque curve and direct drive transmission. This means it can cruise in top gear longer, for better fuel efficiency.
  • Lighter 6x2 Axle: The 6x2 axle configuration incorporates a non-driven tag axle on the tandem, reducing total weight (by 380 lbs) and the number of moving parts, delivering better fuel economy.
  • New Optional Axle Lubrication Management (ALM): The tandem rear axles feature an optional axle lubrication management (ALM) system that actively regulates the oil level at the ring gear and friction-loss optimized pinion bearings to reduce friction and parasitic loss, extending gear life and further improving fuel efficiency.


  • 1-Box: The 1-Box is a complete aftertreatment emissions system that combines the SCR catalyst, the Diesel Oxidation Catalyst (DOC), Diesel Particulate Filter (DPF) and Diesel Exhaust Fluid (DEF) all into one simple component.

Brochures and Spec Sheets

Detroit Powertrain Product Overview Guide (Freightliner New Cascadia) Detroit Integrated Powertrain Brochure

ghg17 vs ghg14 engine fuel efficiency & def usage calculator

Reducing CO2 emissions and meeting 2017 Greenhouse Gas (GHG17) requirements means better fuel economy. Compare how our GHG17 Compliant Detroit® engines stack up against GHG14 engines. Our GHG17 engines provide better fuel economy while using a slightly higher amount of Diesel Exhaust Fluid (DEF). See for yourself how these engines will affect your operating costs.





Sharing common service operations and parts with the DD13® and DD16® ensures that trained technicians are ready to serve you and your DD15® at any of our 800+ authorized Detroit locations across the highways and back roads of North America.

Brochures and Spec Sheets

Detroit DD15 French Brochure Detroit DD15 French Product Overview Guide Detroit Engines Spanish Driver Card Detroit Engines French Driver Card Cascadia Detroit Engines Driver Card - French Cascadia Detroit Engines Driver Card - Spanish Cascadia Detroit Engines Driver Card


Detroit Optimized Idle Training Video Detroit DDEC Training Video Detroit DD15 GHG17 Product Video Detroit Engine Assembly Video Detroit Engines Regeneration Training Video Detroit DDEC Training Video Detroit Engines Family Product Video PasSmart Training Video Detroit DD15 Overview Video Ralenti optimizado - Motor encendido - Video de entrenamiento Ralenti optimizado Detroit - Video de entrenamiento Optimized Idle - Engine Not Running Training Video Optimized Idle - Engine Running Training Video Optimized Idle - System Safety Loops Training Video Parked Regen GHG17 Dash Cluster - Overview Training Video Regeneracion Estacionaria GHG17 - Cluster Dash - información general d - vídeo Ralenti optimizado - Motor apagado - vídeo de entrenamiento Ralenti optimizado - Video de entrenamiento de bucles de seguridad del sistema Diesel Particulate Filter (DPF) Cleaning Procedure Video BlueTec Emissions Technology Video


Detroit Engines Trinity Image Detroit DD15 Hot Profile Image Detroit DD15 Hot 3/4 Image Detroit DD15 Hot 3/4 Low-View Image Detroit DD15 Cold Profile Image Detroit DD15 Cold 3/4 Image Detroit DD15 Six-Blade Fan Image


Maintenance Intervals


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Detroit Connect Portal

The Detroit™ Connect portal is easy-to-use, one-stop-shop for all vehicle performance data gathered, transmitted and analyzed by Detroit Connect.  The portal gives you access to insights delivered by  Detroit Connect Virtual Technician℠. The Detroit Connect portal will also give you access to new features, such as Remote Updates, and Analytics, available late 2017.

Detroit connect portal login


All DDCSN content has been migrated to our DTNAConnect web portal. All information previously on the DDCSN is now on DTNAConnect. We have created a quick reference guide to help you locate the migrated content on DTNAConnect. Existing DDCSN login credentials will also work with DTNAConnect. Please work with your security administrators for login or content issues. If you do encounter any technical issues, please contact the Software Support Center at 855-639-8680 or


DTNA Connect Portal

DTNA Connect is the starting point for working with all brands and franchises that fall under the Daimler Truck North America umbrella: Detroit, Thomas Built Buses, SelecTrucks, Sterling, Freightliner, and Western Star. Here, you can access the full spectrum of online applications, resources and tools you need. Whether you use DTNA online resources to complete repairs, purchase parts, submit warranty claims, spec new vehicles or track the status of your truck orders, DTNAConnect streamlines the tasks and activities that are part of your daily work routine.

DTNA Connect Portal Login