General Motors is shooting for the moon with its 2010 Duramax-equipped HD pickups (GMC Sierra HD and Chevrolet Silverado HD), anticipating that it will meet full Tier 2 Bin 5 federal emissions regulations. The upgraded 2010 Duramax is rumored to be in the 700 lb-ft of torque range, with significant increases in horsepower as well. But what's interesting is that to meet the emissions goals, GM may be utilizing a urea fluid system to cut down on Nox emissions in the V8 diesel. Urea is an ammonium fluid that is injected into the exhaust system, converting nitric oxides in the exhaust into water and atmospheric nitrogen. The system is commonly referred to as Selective Catalytic Reduction, or SCR. Adding an SCR system to a truck requires an auxiliary tank (which must be maintained at regular service intervals), pump, urea fluid lines and exhaust system couplers.