Today GM released power figures for the heavily-revised 2011 Chevrolet Silverado HD. Thanks to a few well-connected sources, regular GM Authority readers (and listeners) knew in advance that this was going to be a surprise. And what a shocker it was!

6.6 Duramax Diesel

GM’s top-of-the-line 6.6-liter Duramax diesel is the most powerful heavy duty engine in its class – putting out a whopping 397 hp (296 kW) and 765 lb.-ft. (1,037 Nm) of torque!

6.0 Vortec Gasoline

On the gasoline side of the spectrum, GM’s Vortec small-block – the standard powerplant for the Silverado HD trucks – also received some revisions for the 2011 model year. When in the 2500 and 3500 HD models, the 6.0L small-block V-8 is rated at 360 horses (268 kW) and 380 lb.-ft. (515 Nm) of torque. In chassis cab and box-delete models, as well as Silverados with a GVWR greater than 10,000 pounds, the gas engine’s horsepower rating drops to 322 horsepower (240 kW) while retaining the same torque rating. The 6-liter Vortec is further enhanced by “greater idle refinement” and achieves “excellent fuel economy” by the engine’s low-friction OHV set-up and cam phasing. Needless to say, this is GM’s small-block architecture (LS family) known for its strength, smoothness, and durability.

Warranty

What we haven’t mentioned is that all 2011 Silverado models are covered under the best warranty coverage in America – a five-year/100,000-mile limited powertrain warranty that includes roadside assistance and courtesy transportation, among other features.

Yet even with these massive numbers, the Silverado Heavy Duty is still out-trucked by Ford’s latest incarnation of the F350 Super Duty. That’s right – not only can the updated SuperDuty tow more, but its payload is also higher than that of the most-powerful Silverado. In any event, we have GM’s full press release after the jump! and images upon images in the gallery of the 2011 Silverado HD (more…)