History of the diesel car featured an aluminium block, DOHC chain driven valvetrain, common rail direct injection and variable geometry turbocharger. In Spring 2005, Mercedes-Benz unveiled their first application of a mass-produced aluminum block diesel engine for passenger vehicles and commercial use. While aluminum is traditionally considered of inferior strength and temperature resistance to withstand diesel applications, Mercedes engineers made extensive use of CAD/CAM design to arrive at an aluminum block that would meet with Mercedes' testing and reliability standards. First use was in 2006 model-year vehicles in the E-Class sedan and ML-class and GL-class SUVs. Similar in weight () to the five-cylinder it replaced,
Budd Rail Diesel Car Administration under license from Budd. Designated the DR2800 series, the units are organized into 15 permanently-coupled three-car sets (30 powered driving cars and 15 trailers). Like other RDC trainsets before them, each cab unit only has a cab at one end and two cab units bracket a trailer in a standard set. Unlike other RDC sets, however, the trailer's diesel engine is used exclusively to provide head-end power for the entire three-car set, while the engines in the driver car are used for propulsion. To prevent dependency on the trailer's engine for cooling, the cooling fans of the driver cars