Sierras Duramax 66 liter is top of its class

Automobile Staff

Sometimes you just need the biggest engine possible to get the job done.

Thanks to an optional Duramax 6.6-liter V-8 diesel, GMC truck owners breathe a little easier than their Ford and Dodge counterparts when it comes to hauling heavy work loads.

Pushing out 660 lb-ft of torque and 365 hp, the Sierra HD is the most powerful full-size truck on the market. Comparatively, Dodge's full-size trucks feature an engine with 650 lb-ft of torque and only 325 hp, while Ford's Super Duty engine can’t measure up with just 650 lb-ft of torque and 350 hp.

But if you're more concerned about green technology, GMC’s FlexFuel Vortec 5.3-liter V-8 runs on any combination of E85 and regular-grade gasoline. With the Vortec engine, Sierra two-wheel drive models get 315 hp and can return 20 mpg thanks to an Active Fuel Management system that deactivates four cylinders during light-load conditions.

And if GMC owners ever have any problems getting all that bullish, green power, all GMC vehicles come with a 5-year/100,000-mile powertrain warranty.

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