According to a recent article, the Hummer H2 and Chevrolet and GMC light-duty pickups built after 2009 will come available with an all-new 4.5L V8 Duramax turbodiesel. The new powerplant will be produced at General Motors Corp.'s Tonawanda, New York, plant.
According to the article, the 4.5L Duramax is a means of improving the fuel efficiency of some of the automaker's biggest vehicles. The new engine is expected to emit 13% less carbon dioxide than existing gasoline engines. It will also reduce the particulates and oxides of nitrogen emissions by 90% over today's diesel powerplants. Tom Stephens, group vice-president of GM's global powertrain and quality, says that the new diesel "is expected to become a favorite among customers who require excellent towing ability and fuel efficiency." The new Duramax will meet all 2010 emissions standards in the United States and will be 50-state compliant.

The 4.5L will be a DOHC V8 with more than 310 hp and 520 lb.-ft. of torque. It will also be the first GM engine to feature selective catalytic-reduction exhaust aftertreatment and a diesel particulate filter, which will help it meet the new U.S. Tier 2 Bin 5 emissions standards. The powerplant will feature a graphite-iron block, aluminum cylinder heads with integrated manifolds, an intercooled variable-geometry turbocharger and a high-pressure common-rail fuel-injection system capable of five injection events per cycle.
GM officials who were on hand for test drives of the 2008 Hummer H2 and H3 Alpha declined to confirm any details on the aftertreatment technology. However, a urea-injection system will likely be needed to meet future emissions standards, according to the article. One of the most interesting features of new Duramax is its ability to be mounted in the same space as GM's small-block V8 lineup. This allows for easier adaptation for a wide variety of vehicles, as the diesel market continues to grow. Could we see this Duramax in any of GM's passenger cars?
Not only will the new Duramax serve to boost the fuel efficiency of vehicles such as the H2, but as points out, it will also help to improve the image of the Hummer brand, which is under constant attack by the environmentalists. The 4.5L Duramax will also be capable of running on some mix of biodiesel, according to Martin Walsh, Hummer General Manager. GM will be investing $100 million in the Tonawanda, New York, plant where the new diesel will be produced. GM will also dispense an additional $41 million for vendor tooling, containers and investment at other locations. Output of the new diesel is slated to get underway in the fourth quarter of 2009, and the project is expected to retain 150 hourly jobs at the plant.

Source: Sutton, Mike. (June 15, 2007). "Hummer H2 to Feature All-New Diesel After 2009." Retrieved June 18, 2007 from