2017 GMC Sierra HD First Drive: It's Got A Ton Of Torque But That's Not What Sells This Truck

The 2017 GMC Sierra HD really only gets one fresh feature, but it’s a biggie. The truck’s new 6.6-liter Duramax turbo diesel V8 has a massive claimed output of 445 horsepower and 910 lb-ft of torque. It feels good to drive, too. But this truck’s real value proposition isn’t under the hood, it’s in the details.