The demand for improved fuel economy is driving the industry toward a systems-integrated future to achieve higher standards of efficiency. At an event in Detroit, Detroit Diesel Corp. unveiled its new integrated Detroit powertrain, featuring the Detroit DD15 engine, Detroit DT12 transmission and Detroit axles, a powertrain that boasts an 5 to 7% additional fuel economy improvement above the standard set by Freightliner Cascadia Evolution.
To create the integrated powertrain, Detroit’s axle engineers developed a new axle ratio (and configuration) to match the engine rating. The integrated Detroit powertrain features the DD15 engine, with new downsped rating of 400hp and 1750 lb/ft. The downsped rating enables the engine to turn at lower RPMs regardless of road speed, ultimately reducing fuel consumption and friction. Because it delivers the necessary torque at these low RPMs is the engine is able to deliver the power drivers demand, according to the company.
“Downspeeding improves fuel economy by shifting usable power and torque to a lower RPM range,” said Brad Williamson, manager, engine and component marketing for Daimler Trucks North America. “Because we understand how important driver retention is to the Real Cost of Ownership, Detroit engineers made sure to deliver a product that drivers will like.”
The integrated DT12 offers a new Intelligent Powertrain Management (IPM). This technology uses pre-loaded terrain maps and GPS to know the route ahead and automatically adjusts transmission and engine functions, resulting in an even smoother ride. Features such as eCoast, a technology specific to the DT12 that allows the engine to operate at idle of 500 RPM when road and driver inputs don’t require engine power to move the truck down the road, and creep mode, which improves low- speed maneuverability, perform with the powertrain to benefit performance.
“Whether approaching a grade, cresting a hill or traveling along rolling hills, Intelligent Powertrain Management makes sure the truck is carrying the most efficient momentum into the road ahead,” said Williamson. “The DT12 transmission is the critical link between the engine and the axles, and with the addition of the IPM, we are providing a seamless solution that has a direct impact on fuel savings.”
Working together with the DD15 engine and DT12 transmission, the new Detroit rear axles integrate to provide performance. Detroit now offers a 6×2 configuration with a 2.28 ratio that is specifically designed to work with the downsped engine rating, making it the fastest ratio available in Freightliner and Western Star trucks while still providing the performance. The 6×2 Detroit axle configuration incorporates a non-driven tag axle on the tandem, reducing total weight by almost 400 lbs., while a new 2.41 ratio in its 6×4 axle configuration is also available for applications requiring superior traction. The integrated Detroit powertrain includes steer axles that use low-friction needle bearings for maximum maneuverability and minimal maintenance.
Both Williamson and David Hames, general manager, marketing and strategy for Daimler Trucks North America, stressed the efficiency benefits of a 6×2, while noting that Detroit understands a 6×4 is necessary in a wide array of applications.
“There’s a shift happening in the market,” Hames said, comparing the growing acceptance of 6x2s to that of automated manual transmissions. “We’re not going to have a massive 6×2 conversion, but I think you’ll see a higher acceptance in applications where they work because it’s an undeniable fuel economy advantages.”
Because all of the integrated powertrain components were developed by Detroit, they not only share engineering and manufacturing processes, they are supported by the extensive Detroit Customer Support Center and the Customer Service network. The integrated Detroit Powertrain will be available in January 2015 for the Freightliner Cascadia Evolution and later in 2015 for the new Western Star 5700. The new Demand Detroit App will be available for Android and iOS devices in early June.