General Motors Corp. plans to ship the 4.5L V-8 Duramax turbo-diesel engine for trucks and Hummers. The diesel engine technology improves fuel efficiency by 25 percent, reduces CO2 emissions by 13 percent, and cuts particulates and NOx emissions by at least 90 percent. ...
... "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. " ...
Via General Motors: Light Duty V-8 Clean Diesel