General Motors will introduce a new V-8 turbodiesel that improves engine fuel efficiency by 25% for North American light duty trucks after 2009.
Environmental benefits of the new engine include a 13% reduction in CO2 versus gasoline engines, and at least a 90% reduction in particulates and NOx compared to diesel vehicles today. This will be GM’s first engine to use a NOx aftertreatment system along with a diesel particulate filter to help achieve the Tier 2 Bin 5 (T2B5) and LEV 2 emissions standards.
Technical highlights of the engine include aluminum cylinder heads with integrated manifolding, compacted graphite iron (CGI) block for a strong engine base and fracture-split main bearing caps and connecting rods for a precise fit. A high-pressure, common-rail fuel system is used, which has the ability to inject fuel five times per combustion event to control noise and emissions.
The new dual-overhead cam, four-valve V-8 diesel engine will fit within the same space as a small-block V-8 gasoline engine. This compact size is made possible by using an integrated air system and narrow block.
GM says that the premium V-8 diesel will deliver class-leading torque, power and refinement while maintaining a significant fuel efficiency advantage over comparable output gasoline engines.
This new GM light duty diesel is expected to become a favorite among customers who require excellent towing ability and fuel efficiency. It will meet the stringent 2010 emissions standards, and it will be compliant in all 50 states.—Tom Stephens, group vice president, GM Powertrain
GM also announced that it has revised its Duramax 6.6-liter V-8 turbodiesel engine to meet 2007 federal emissions regulations.
Upgrades to the engine and a new diesel particulate filter system help ensure the engine meets government-mandated emissions regulations for diesel engines manufactured beginning in January 2007, which require a 90% reduction in particulate matter and 50% reduction in NOx.
To meet the new emissions regulation, the Duramax 6.6L V-8 engine features:
Additional combustion control, including an even more efficient variable-geometry turbocharging system, cooled (enhanced) Exhaust Gas Recirculation (EGR) and closed crankcase ventilation to reduce NOx.
Additional exhaust control, including oxidizing catalyst and new Diesel Particulate Filter (DPF) to reduce soot and particulate matter.
Increased-capacity cooling system.
New engine control software.
Use of low-ash engine oil.
The new Duramax 6.6L V-8 (LMM) engine offers versions with 300 hp (224 kW) and 520 lb-ft (705 Nm) of torque, as well as a new 330 hp (246 kW) option with 620 lb-ft (841 Nm) of torque.