REDFORD, Mich. — Detroit Diesel has unveiled its new heavy-duty engine, the DD15, which the company says will offer improved performance and fuel mileage along with a quieter ride.

The new 14.8-litre engine will be available in the Freightliner Cascadia in the second quarter of 2008. It will be complimented by a 12.8- and 15.6-litre version which will ultimately replace the MBE-4000 and Series 60 engines, likely by 2010.

The new engine series will utilize a new Amplified Common Rail System (ARCS), Detroit Diesel officials announced, as well as a new turbo compounding technology. The DD15 will also serve as the base for future Daimler Truck engines manufactured around the world, with 90% parts commonality.

The DD15 was five years in the making and represented an unprecedented investment of US$1.5 billion, the company announced at the product launch in Detroit on Friday. The investment includes US$275 million in plant upgrades to allow for production at Detroit Diesels Redford, Michigan factory.

The 14.8-litre DD15 will be available with horsepower ranging from 455 to 560 hp and torque outputs from 1,550 lb.-ft. to 1,850 lb.-ft. The engine will be able to accommodate Selective Catalytic Reduction (SCR) components to comply with EPA2010 emissions standards, the company said.

Instead of revamping one of our current engines to comply with EPA standards, we designed a brand new platform that takes all of the emissions requirements into account, explained Jim Gray, Detroit Diesel program director for the DD15.

Detroit Diesel officials say the DD15 is an upgrade over the Series 60 in many areas, including fuel consumption. A fuel savings of 3-5% over the Series 60 is expected, thanks to the ACRS fuel system and simplified turbocharger technology. It is also superior when it comes to torque, delivering full torque sooner and maintaining it longer than the Series 60, engineers explained. In fact, Detroit Diesel is touting a 75% improvement in torque response over its current engines.

The ARCS injection system is an industry-first, and results in quiet operation with improved fuel economy, the company said. Also contributing to fuel economy improvements is the engines turbo compounding technology.

At the rated engine speed of the DD15, the turbine reaches a rotation speed of more than 40,000 RPM, the company explained. Power is transferred to the gear drive, and therefore to the crankshaft, via a shaft and a hydrodynamic coupling. This arrangement produces a uniform and smooth crankshaft rotation despite the higher torque.

The DD15 has undergone extensive testing and has already racked up more than 100,000 operating hours, the company said. That equals several million miles on the road. There are currently 20 tractor-trailer combinations on the road today.

“The DD15 is a best-in-class engine that embodies what the Detroit Diesel brand is all about: performance and efficiency,” announced Chris Patterson, president and chief executive officer of Freightliner LLC. “Paired with our trucks, financing, and an expansive service network, DD15 is destined to make our customers even more successful in the years to come.”

For a full report on the new engine, including first-hand observations, see the December issues of Truck News and Truck West.