The GMC Sierra is an upmarket version of the ubiquitous . The Sierra Denali is the varsity version of the Sierra. And the Sierra Denali Heavy Duty, well, my friends, that thing’s badder than Snoopy in a leather jacket. At least that’s what the brochure seems to indicate. I’m test driving it this week, so what do you want to know?

GMC’s HD trucks start at about $35,000, for a basic 2WD 2500, and get into the $60,000 range with the big cab, long bed, dual rear-wheel, Denali diesel luxury loadout. Start adding options and you’re over $70,000.

When we’re talking standard consumer trucks, “heavy duty” is automaker vernacular for three-quarter (2500) and one-ton (3500) vehicles. This refers to the minimum weight the trucks are rated to carry in their beds, also known as payload.

The Sierra HD lineup is revised for 2017 with a new more powerful diesel engine and a vaguely off-roadish “All Terrain X” trim level.

The 2017 truck’s 6.6-liter Duramax V8 turbo diesel has the same displacement as last year’s model, but a new block, cylinder heads, upgrades to the oil cooling system, electronic controls on the turbo, and an upgraded crankshaft. those and a few other tweaks bump the power up to 445 horsepower and 910 lb-ft of torque which comes on from 1,550 rpm through 2,850 rpm.

The 2016 truck was rated to 397 HP at 3,000 rpm and 765 lb-ft of torque at 1,600 RPM. As for the current competition, Ford its recently-updated 6.7-liter Power Stroke diesel at 440 horsepower and 925 lb-ft of torque, while Ram’s 6.7-liter Cummins I6 is “up to” 385 HP and 900 lb-ft of torque.

Frankly, each of the three automaker’s HD truck line is mighty but we’re hoping to dig a little more into what makes the GMC stand out while we drive it from Telluride, Colorado to Moab, Utah.

The model doesn’t seem to be anywhere near as much of a hardcore off-roader as a Ford Raptor, Toyota Tacoma TRD Pro or Chevy Colorado ZR2. Or a Ram Power Wagon, to use a closer size-equivalent. But I must say I dig the look. And as I’ve learned over the last few years, a good set of tires and halfway decent shocks go a long way so hopefully, we get the chance to get one muddy.

Other tweaks to the new truck include some more sound deadening and of course that gaping maw of an air intake, which, according to GM, is functional.

Shoot me your questions about details and specifics you can’t read in the brochure for me to find out and pass along to GM’s engineers while I shake down a few variants of the GMC Sierra HD.