Filed under: Diesel, Chevrolet, GM, HUMMER
More information on GM's new light duty diesel V-8

We gave a pretty detailed write-up last summer on GM's new light-duty diesel V-8 that will premiere in 2009. The new engine was specifically designed to fit within the same package dimensions as the long-running small-block V-8. As such, the diesel can potentially be installed in any GM vehicle that currently carries the V-8. GM has announced that the new 4.5L engine will have output of 310hp and 520lb-ft of torque. The Duramax 4500 will also provided a 25 percent reduction in fuel consumption compared to the similarly powerful gasoline engines. That puts it on a par (when comparing combined city/highway numbers) with the two-mode hybrid system when it debuts in the Chevy Silverado and GMC Sierra pickups next year.
When the engine debuts for the 2010 model year it will be the first GM diesel to use selective catalytic reduction (SCR) to reduce NOx emissions. SCR is also known as urea injection. Vehicles with this engine will meet Tier 2 Bin 5 standards and be fifty-state legal. In order to fit the dual overhead engine in the space of the cam-in-block small-block, GM engineers reduced the angle of the block and reversed the intake and exhaust flow through the cylinder heads. The intake valves are now on the outside of the heads and the manifold feeds air in from the top. The exhaust manifolds are now in the valley of the block along with the turbocharger. Previously, GM has also indicated that this engine would also go into the Hummer H2 which would do a lot to improve that vehicle's mileage.
[Source: General Motors]
PRESS RELEASE
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.
Technical highlights
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.

Reader Comments (Page 1 of 1)
Ernest Barrow 7:11PM (5/06/2008)
I am very interested in a diesel Hummer H3 which I plan to buy later this year. However, I cannot find much information about this possibility. There is talk about biodiesel but that needs to be explained as opposed to regular diesel.
There is a gentleman that can retrofit biodiesel Hummers to produce up to 60 MPG. That is where my interest is
Reply
Sam Abuelsamid 7:20PM (5/06/2008)
Ernest, it's highly unlikely any Hummer is going to get 60mpg no matter what kind of diesel you put in it. The horrible aerodynamics, and high weight just don't make that a realistic proposition. As for a diesel H3, that's probably at least two years away. The h2 will be first.
Reply
Stéphane Dumas 8:54PM (5/06/2008)
#1 Ernest, I digged the AutoblogGreen archives and I found the article about the 60 mpg Hummer (who also use biodiesel, but note then he used a turbine however)
http://www.autobloggreen.com/2007/10/20/biodiesel-turbine-super-capacitor-series-hybrid-hummer-60/
Reply
why not the LS2LS7? 10:22PM (5/06/2008)
That guy is a scam artist.
Reply
rob 10:54PM (5/06/2008)
I'd be far more impressed if they'd lopped off a bank of cylinders and announced they'd be sticking a 2.25L 4-cyl with 160hp and 260ft-lbs in their cars as a volume engine for the US market...
Reply
Michael Hippenhammer 3:43AM (5/07/2008)
I totally agree with #5 rob. That will have the biggest impact on reducing the amount of fuel the US uses. But, you will need to talk to the people in charge of refining diesel fuel to increase the size of their diesel production or we will see diesel go up in price. I think it's a conspiracy to discourage diesel vehicles in the US.
Reply
Guenther 8:50AM (5/07/2008)
Ernest- The only Diesel H3s currently on the horizon is the Right-hand drive South African model. The base motor for the US H# will switch to the High Feature V6 in the next 18 months (2010 MY IIRC). At that time the VM 2.9L V6 diesel could be fitted. As for the 60mpg claim, cannot be done with conventional technology. You can hope for mid to high 20's at best.
Reply
2007 Sierra Classic 8:27AM (5/09/2008)
Its good to see a little more information on this engine. From what I am seeing it's looking to be exactly where I thought it would be at for numbers. Now I just want to know about the cost compared to my same power 5.3Litre gasoline model. In Canada currently Diesel is more expensive or on par with gas in all situations other than comercial and farm. If the engine even costs say 7500 more than its gas counterpart my math says that it doesn't make the cut in the cost department.
Reply