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  In 2007, General Motors released it's Duramax 6.6 liter V8 Turbo-diesel engine. Designed to be a powerful, efficient diesel engine for use in medium and heavy-duty trucks, vans and transport trucks, the engine underwent strict revisions to maintain it's power while still complying with the then recently mandated new low-emissions standards. These revisions contributed to further enhancing the engine's efficiency and smoothness. The revision also made what was already considered one of the industry's quietest diesels even quieter.
  
  

Operation

• The 6599cc Duramax Turbo-Diesel is outfitted with a direct-injection diesel system, with a compression ratio of 16.8:1 and a bore and stroke of 103mm by 99mm. The valve lifters utilize a mechanical roller and the engine utilizes an overhead valve system, arranged with four valves to each cylinder.
  
  

Horsepower

• The horsepower on the Duramax Turbo-Diesel varies depending on the vehicle where it's installed. The Chevrolet Silverado HD and GMC Sierra HD offer the most power, with 360 horsepower at 3200rpm. Next, the Chevrolet Kodiak Medium Duty, and GMC TopKick Medium Duty, with the LYE option, offer 330 horsepower at 3000rpm. The same model Kodiak and TopKick, with the LRX option, clock in next at 300 horsepower at 3000rpm. The Chevrolet Express and GMC Savana round out the bottom of the Duramax's power output, offering 250 horsepower each at 3200rpm.
  
  

Materials

• The Duramax Turbo-Diesel engine's main block is made of cast iron, while the cylinder heads and intake manifold are made of cast aluminum. The exhaust manifold is made from cast nodular iron, with steel pipe extension, while the main bearing caps are cast nodular iron. The crankshaft is made of forged steel, while the camshaft is made of normal steel. The connecting rods are made of stress fractured forged steel.
  
  

Emissions Control

• To control it's emissions, the Duramax Turbo-Diesel features a catalytic converter, cooled exhaust gas recirculation, an intake throttle and a diesel particulate filter.
  
  

Maintenance

• To maximize the lifespan of the Duramax, use CJ-4 engine oil, and change the coolant every five years or 150,000 miles. The computerized Oil Life System, installed in all GM vehicles using the Duramax Turbo-Diesel, indicates to the driver when the oil needs to be changed and should be checked frequently.