GM has recently announced the power ratings for the 2011 Duramax Diesel V8, and its up – WAY up. The 2011 Duramax will have 397 hp and a whopping 765 lb.-ft. of torque, up 32 hp and 105 lb.-ft. from the previous Duramax. As you can see from the chart below, that gives the Silverado/Sierra HD an advantage in both horsepower and torque over its diesel bretheren from Ford and Dodge. (Thanks to pickuptrucks.com for the chart.) Some of the features of the new Duramax, from the official GM press release:
* Main bearing profiles changed to enhance oil film thickness
* Oil pump flow increased for more pressure at low speeds
* A revised turbocharger oil circuit for increased pressure at the turbo and faster oil delivery
* Connecting rod pin ends modified to provide increased piston support
* New, higher-strength piston design
* A new 30,000-psi (2,000 bar) piezo-actuated fuel injection system – capable of operating on ASTM grade B20 biodiesel – ensures more precise fuel delivery, improving emission performance
* An EGR cooler bypass reduces high-mileage soot deposits in the cooler and EGR circuit (pickup versions only).
The more powerful 6.6L Duramax is also more fuel-efficient – up to 11-percent greater highway fuel economy than the outgoing model – reduces NOx emissions by up to 63 percent and helps enable greater towing ratings. Silverado 3500HD equipped with a fifth wheel hitch can tow up to 20,000 pounds (9,072 kg). The increased fuel efficiency, combined with a new, 36-gallon (136 L) fuel tank, provides up to 680 miles (1,090 km) of highway driving between fill-ups.
With nearly 1.3 million Duramax diesel engines put into operation since its launch in 2000, no other automaker has as much diesel engine development experience for meeting the demands of the heavy-duty truck customer