• Jun 15, 2007
Mark your calendars, because we're calling today a watershed moment for the advancement of diesel's acceptance in the U.S. General Motors has just announced a new 4.5L V8 Duramax turbo-diesel powerplant it plans to use in the Chevy Silverado and GMC Sierra half-ton pickups, as well as the HUMMER H2. The new oil burner is expected to produce at least 310 horsepower and 520 ft-lbs. of torque. It features dual-overhead cams, four valves per cylinder, a variable-vane turbocharger and aluminum cylinder heads with integrated manifolding that helps keep the overall package small enough to fit in the same space as the automaker's small-block gas V8s.

That's right, just imagine the possibilities. Wherever GM uses a small-block V8 gas engine, it could potentially use the 4.5L V8 Duramax diesel. In a few years we could be driving diesel Impalas, diesel Camaros, maybe even a diesel Corvette! To quote GM's press release, the engine's small size gives it "the flexibility to introduce this engine in a wide variety of vehicle applications should there be future market demand." Indeed.

GM estimates that the engine will improve fuel efficiency by 25 and decrease particulate and NOx emissions by at least 90% in its GMT900 pickups and the HUMMER H2. Whoever said the HUMMER H2 was on its way out will likely be proven incorrect after this engine debuts. Scheduled to be built at the GM Tonawanda engine plant outside Buffalo, NY, the 4.5L V8 Duramax diesel will be 50-state emissions compliant and meet 2010 diesel emissions standards, as well. GM claims its new diesel will also have NVH (Noise, Vibration and Harshness) levels approaching those of today's current gas V8s, though we'll have to wait and see if that wish comes true. That wait should end in a couple of years, as the automaker states the engine will be available in Silverado, Sierra and H2 models built after 2009.

UPDATE: Pickuptruck.com's Mike Levine has learned from GM that despite sharing its name with the older 6.6L Duramax diesel that was developed in partnership with Isuzu, the new 4.5L Duramax was developed completely in-house by GM.

Check out GM's full press release after the jump for more details.

[Source: GM]

PRESS RELEASE:

GM Plans First Light Duty V-8 Clean Diesel For North America
  • High-efficiency V-8 scheduled for pickup trucks under 8,600 pounds Gross Vehicle Weight and HUMMER H2
  • Low emissions, high performance and excellent fuel economy
  • Expected to deliver class-leading torque, power and refinement
  • Manufactured at the GM Powertrain Tonawanda engine plant
TONAWANDA, N.Y. – General Motors Corp. will introduce a new, state-of-the-art 4.5L V-8 Duramax turbo-diesel that improves engine fuel efficiency by 25 percent, reduces CO2 emissions by 13 percent and cuts particulates and NOx emissions by at least 90 percent for North American light duty trucks and the HUMMER H2 built after 2009.

The premium V-8 diesel is expected to deliver class-leading torque, power and refinement while maintaining a significant fuel efficiency advantage over comparable-output gasoline engines.

The new dual-overhead cam, four-valve V-8 diesel engine will fit within the same space of a small-block V-8 gasoline engine. This compact size is made possible by using integral cylinder head exhaust manifolds, integral cam cover intake manifolds and a narrow block.

"This new GM light duty diesel is expected to become a favorite among customers who require excellent towing ability and fuel efficiency," said Tom Stephens, group vice president, GM Global Powertrain and Quality. "It will meet the stringent 2010 emissions standards, and it will be compliant in all 50 states, making it one of the cleanest diesel vehicles ever produced."

Environmental benefits of the new engine include a 13-percent reduction in CO2 versus gasoline engines, and at least a 90-percent reduction in particulates and NOx compared to diesel vehicles today. This will be GM's first engine to use a selective catalytic reduction NOx aftertreatment system with a diesel particulate filter to help achieve the Tier 2 Bin 5 and LEV 2 emissions standards.

Technical highlights of the engine include aluminum cylinder heads with integrated manifolding; a variable-vane turbocharger with intercooling; a Compacted Graphite Iron (CGI) block for a stronger and lighter engine base (compared to lower-strength aluminum or heavier grey cast iron); and fracture-split main bearing caps and connecting rods for a precise fit. An electronically controlled, ultra-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.

"This new V-8 is not only a clean diesel meeting the toughest emissions requirements in North America, 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 other diesels on the road today, with noise and vibration performance approaching gasoline V-8 levels."

Freese said the new V-8's compact size enables it to fit in the envelope of a gasoline small-block engine, which provides GM the flexibility to introduce this engine in a wide variety of vehicle applications should there be future market demand.

The premium V-8 diesel engine is expected to deliver class-leading refinement, horsepower and torque and fulfill multiple vehicle applications with ratings in excess of 310 horsepower and 520 lb-ft of torque.

GM (Opel, Saab, Vauxhall and GMDAT ) currently offers 17 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 sold in the Opel Agila and Corsa, up to the 6.6L V-8 Duramax diesel sold in full-size vans, heavy duty pickups and medium duty trucks in the U.S.

GM first introduced the Duramax diesel 6.6L V-8 in the U.S. in the 2001 model year and since then, customer enthusiasm for this heavy duty diesel has been outstanding. In fact, GM's heavy duty pickup truck market share has jumped nearly tenfold in the six years that Duramax engines have 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 280,000 people around the world. With global headquarters in Detroit, GM manufactures its cars and trucks in 33 countries. In 2006, nearly 9.1 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.


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  • 71 Comments
      • 5 Years Ago
      I'm in if it will get at least 24 mpg empty. My primary hope is that GM does not put a premium price tag on the thing. Regardless the mpg-40 thousand bucks or higher knocks me out of the market.
      • 6 Years Ago
      Just wanted to let you guys know...My buddy at work gets 22-26mpg in his 2500 Ram Big 4 seater dually 4x4. I laughed at him until we went on a 600 mile round trip/ hunt outing in north AZ and he let me do the math for the fuel costs. He's tweaked the engine and fuel system somehow and chipped the computer, whatever that means. Long story short, I'm out shopping for a new diesel. My gasser gets 11mpg consistantly (no OD and 4X4). The rumor I heard was that this 1500 diesel would conservatively get 25-30 mpg. I can't wait.After tweaking, then what? My current fuel costs will pay for my new truck. I'm in line.
      • 6 Years Ago
      For those asking about "what a light duty truck would be like." Just take a step into the past.

      I drive a 1981 Chevy LUV. It's really a re-badged Isuzu P'up. The beginning of their relationship.

      I make 59hp, and only slightly more torque. 2.2l of naturally-aspirated bulletproof love. Yeah, over 1.7 MILLION miles on this thing. All original.

      Look at VW's current engine offerings in the same displacement, and we can easily see how this size of an engine can be advanced by 25 years.

      And yes, that's exactly why I bought it; there are no new ones to buy.

      I get almost 50mpg no matter where or how I drive it, and it loves alternative fuels. This is due to the IP tho. Who knows what a new IP will do. Dodge/Cummins has shown us plenty of times that they know how to screw up a good engine by using a crap IP. Even VW's new engines use a weak IP that can't handle heavier fuels. The Conspiracy Theorist in me wonders if that's an accident.

      Anyway, look at how sweet this little truck is. But it tanked sales because American Buyers were too dumb to know better. Repeat? Does Detroit want to run that risk again?
      • 6 Years Ago
      okay, i love GM and all, but i just dont know about this 4.5L diesel...i think ill stick to the 6.6L turbo diesel, but for what they are compairing it to...i think its the 4.8L 1500 small block, or the 5.3L 1500...but it might be a good truck for travel, i just dont see it hauling a big farm fifth wheel...so i still say 6.6L is on top but very expensive
      • 7 Years Ago
      @ Snix -

      building a reliable 4-banger turbodiesel isn't the issue, there are plenty of those plying the streets of Europe (mostly around 2.0L displacement). The problem is that EPA/CARB emissions standards are so strict that the technology required to meet them would price such a small diesel out of the market.

      Example: MY2007 Colorado Work Truck, 2.9L I4 gasoline, 2WD, 5-speed manual officially gets 20/26 MPG. Figure 15,000 miles annually and $3.50 average for gas over the next 8 years. Total lifetime fuel cost $18260.

      Now figure a clean diesel option offering similar performance would cost $3000 more but get 25/33 MPG of *gasoil*. Figure same mileage, same length of ownership, but an average of $3.80 per gallon of diesel. Total lifetime fuel cost $15724, i.e. about the difference in initial purchase cost. However, you'd also have spend more on AdBlue, VLF, insurance and maintenance.

      Unless the MPG improvement were substantially more than 25% higher, you would qualify for a tax credit and/or you could write off the asset as a business expense, such a small diesel might not be the better choice. The externalities of the US market don't favor diesels the way those of the European market do.
        • 7 Years Ago
        That's some interesting data you're using. Current diesel prices are lower than gasoline prices. This should continue as more diesel output comes online. Then again, perhaps you've seen far different forecasts than I have. a 3L or smaller engine, like what would be appropriate in a midsize truck, should be able to use a NOx trap instead of SCR. That's what Honda is going for with their V6.
        Also, at least here in the Midwest, most people I know drive far more than 15k per year. I do about twice that- about 20k of it is for work. I suppose it holds true, as it always has- Diesel makes sense to the serious user, not so much for the casual user.
      • 7 Years Ago
      Build a reliable 4 cylinder version for the Colorado/Canyon trucks and I'll be impressed.
      • 7 Years Ago
      "This will be GM's first engine to use a selective catalytic reduction NOx aftertreatment system with a diesel particulate filter to help achieve the Tier 2 Bin 5 and LEV 2 emissions standards."

      The emissions control system seems conceptually similar to the Daimler Blue-tec diesel engine.
        • 7 Years Ago
        Sorry - I should have been more explicit. In half-ton pickups (GMT900 compared to Ram), GM is using urea while Chrysler is going urea-free.

        BlueTec, of course, is the name of a suite of diesel emissions technologies from DCX, among which you can find both urea (AdBlue) or urea-free approaches to scrubbing NOX.
        • 7 Years Ago
        Actually, they only share commonality around the diesel particulate filter (DPF) which is used to trap and incinerate soot.

        For NOX control, GM has chosen to use urea SCR to remove NOX while Dodge is using Cummins's "adsorber" catalyst - a urea-free approach that uses a specially coated metal filter that stores NOX and later converts it to nitrogen and water vapor.

        The pros and cons: GM's urea solution is cheap but requires owner maintenance to refill the urea tank. The Cummins adsorber is maintenance free but it requires some expensive precious metals for its composition.
      • 7 Years Ago
      i hope that it is a low cost option because not to many buyers are going to add $4k/$6K to the price of a new half ton pickup. it also better be available in the base truck not just in a full decked out top of the line
        • 7 Years Ago
        I agree - I want to be able to select an engine without it being part of a package that includes heated leather seats, a navigation system, and an in-dash espresso machine. I don't want to pay for all of that if I don't want it.
        • 7 Years Ago
        That's a good point - I never thought of it from that perspective.
      • 7 Years Ago
      I'm glad there is a diesel on the way. Im not so happy that it will only get 20% better fuel milage. Around 17 mpg is'nt anything to shout about. What about just tapping Isuzu for a six cylinder. Not all of us with half ton's need 510 lb/ft. I guess i'm left out again.
      • 7 Years Ago
      Albert,
      I'm sorry the blatant sarcasm, mocking the stupidity of a great number of those posting on this site, was either too obvious or not blunt enough for you understand its point.
      • 7 Years Ago
      Nice diesel. Time to laugh at me. HAHAHA. I have full-size 2 door Pontiac Bonneville with an Olds. 350 diesel. Yes, it runs. Not high horsepower, but great mileage for a vehicle that big. I like being different.
      • 7 Years Ago
      A fuel-efficient H2? I'll have to find a new reason to hate them...
        • 7 Years Ago
        Crappy headlights.
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