The battle of the diesel-powered half-tons is about to begin, and today General Motors revealed more details on its entrant: the 4.5L Duramax turbo-diesel V8. Thanks to a narrow-angle V block, the 4.5L turbo diesel will fit in the same space as the General's small-block V8, which does give us hope for additional applications beyond just its half-ton trucks. Large SUVs are surely going to get the engine as an option eventually, but maybe GM can find a passenger car or two down the line that would benefit from the tons of torque this engine will produce. GM says the 4.5L turbo-diesel will produce 310 horsepower and 520 pound-feet of torque, while bumping fuel efficiency by 25%. In order to help it meet Bin 5 and LEV 2 emissions standards as well as be 50-state legal, the engine will feature both a diesel particular filter and NOx after-treatment system that uses urea to knock out those pesky nitrogen-based particles. Another engineering coup for the 4.5L turbo-diesel is that GM has reduced its parts count thanks to a design that includes integrated aluminum cylinder head exhaust manifolds and an integral cam cover intake manifold. You'll be able to buy the new diesel in model year 2010 Chevy Silverados and GMC Sierra half-ton pickups, no doubt for a sizable premium over their gas-powered counterparts.
GM READYING V-8 DIESEL FOR 2010 MODEL YEAR NORTH AMERICAN LIGHT DUTY TRUCKS
- Scheduled for GM pickup trucks under 8,500 pounds Gross Vehicle Weight
- Low emissions, high performance and excellent fuel economy
The new dual-overhead cam, four-valve V-8 diesel engine boasts a number of innovative design approaches that have enabled its compact size and mass, including integral aluminum cylinder head exhaust manifolds, integral cam cover intake manifolds and a narrow V-angle block. The new V-8's compact size enables it to fit within the same space of a small-block V-8 gasoline engine and offers GM the flexibility to introduce it in a wide variety of vehicles to meet market demand.
The new 4.5L V-8 diesel is expected to deliver more than 310 horsepower (231 kW) and 520 lb-ft of torque (705 Nm), while delivering a 25-percent engine fuel efficiency improvement versus comparable gasoline engines.
"This premium diesel engine is expected to deliver the power, torque and refinement our customers expect," said Tom Stephens, executive vice president, GM Global Powertrain and Global Quality.
The new V-8 diesel will be GM's first engine to use a selective catalytic reduction (SCR) NOx after-treatment system with a diesel particulate filter to help achieve Tier 2 Bin 5 and LEV 2 emissions, making it compliant in all 50 states. SCR was chosen for its proven NOx reduction capability and durability, and high efficiency while operating in optimal diesel combustion modes, making it a very attractive system to achieve high fuel economy.
The environmental benefits of the new engine include a 13-percent reduction in CO2 emissions and at least a 90-percent reduction in particulates and NOx compared to many diesel vehicles today.
Robust and innovative, the new 4.5L diesel V-8's technical details include lightweight aluminum cylinder heads with integrated manifolding; a variable-vane turbocharger with intercooling; a compacted graphite iron (CGI) cylinder block for a stronger and lighter base engine (compared to lower-strength aluminum or heavier grey cast iron); and a fracture-split main bearing cap system. GM has applied for patents on a number of these features and expects to have several patents granted before the engine launches.
Compared to typical production diesel engines, GM's new 4.5L V-8 turbo-diesel innovatively reverses the flow of air and exhaust gases entering and exiting the cylinder heads. Air enters the engine through ports in the top portion of each cylinder head. Exhaust gases exit inward between the cylinder heads and directly into a turbocharger.
"By using integral cylinder head exhaust manifolds, integral cam cover intake manifolds and a narrow cylinder block, designers saved space and reduced the engine's weight. And because the engine makes more efficient use of heat, fuel economy and performance are enhanced, and noise and emissions are reduced," said Gary Arvan, chief engineer for the 4.5L V-8 diesel.
An electronically controlled, 29,000-psi (2,000 bar) common-rail fuel system is also used on the engine. It has the ability to inject fuel five times per combustion event, reducing noise and emissions while enhancing fuel economy.
"This new V-8 diesel meets the toughest emissions requirements in North America, and it also delivers an effortless performance feel because of its high torque across the speed range," said Charlie Freese, executive director of GM Powertrain Diesel Engineering. "It is also significantly quieter than many other diesels on the road today, with noise and vibration performance approaching gasoline V-8 levels."
GM's global diesel offerings
GM (Opel, Saab, Vauxhall and GMDAT) currently offers 16 diesel engine variants in 45 vehicle lines around the world. GM sells more than one million diesel engines annually, with products that offer a range of choices, from the 1.3L four-cylinder diesel engine found in the Opel Agila and Corsa, to the 6.6L V-8 Duramax diesel offered in full-size vans, heavy-duty pickups and medium-duty trucks in the United States.
GM introduced the Duramax diesel 6.6L V-8 in North America in the 2001 model year. Since then, customer enthusiasm for it has helped GM's heavy-duty pickup market share jump nearly tenfold in the seven years the Duramax has been offered.
General Motors Corp. (NYSE: GM), the world's largest automaker, has been the annual global industry sales leader for 76 years. Founded in 1908, GM today employs about 266,000 people around the world. With global headquarters in Detroit, GM manufactures its cars and trucks in 33 countries. In 2007, nearly 9.4 million GM cars and trucks were sold globally under the following brands: Buick, Cadillac, Chevrolet, GMC, GM Daewoo, Holden, HUMMER, Opel, Pontiac, Saab, Saturn and Vauxhall. GM's OnStar subsidiary is the industry leader in vehicle safety, security and information services. More information on GM can be found at www.gm.com.