The 2021 GMC Sierra HD Review

You don't really care about fuel economy, right?

SAN DIEGO — I've driven a lot of large vehicles, but it's hard to overstate how enormous a heavy-duty truck is these days. These are the 2500/3500 variants of the big pickups from Ford, RAM, Chevrolet and GMC.

I heard from one of the big three that while something like 25 percent of half-ton, medium-duty truck owners (AKA the 1500-variants) tow once per month, a whopping 75 percent of heavy-duty 3/4- and 1-ton truck owners do.

That's an awful lot of towing, and it's the big dividing point between the 1500 and 2500/3500 truck buyers. Whether it's horse trailers, campers, toy haulers, construction equipment, a whole bunch of cows, or agriculture products, big American pickup trucks can get the job done.

That's why the big truckmakers use such sturdy language for their slogans: Guts. Glory. Ram.; Built Ford Tough; Professional Grade. You can almost feel the testosterone surging.

But it's more than just heavy trailers and rugged capabilities that people want from a truck. While some might opt for a luxurious auto like a Mercedes-Benz or a BMW, there are plenty of well-to-do truck buyers too. Truckmakers have been only too willing to sell lux trucks to anyone who will buy them, and the sky's the limit.

This brings us to my test vehicle this week: the 2021 GMC Sierra HD Denali, weighing in at a really-quite-reasonable $69,305. That's a whopping 14 grand less than the GMC Yukon Denali I tested a few months back and for a whole lot more capability.

But what do you get for your 70 large? In my case, a 6.6-liter V8 engine making 401 horsepower and 464 lb-ft of torque. That's nothing to sneeze at, but the $10,000 diesel option ups the torque figure to a deeply impressive 910 lb-ft if you're towing particularly hefty stuff.

But if you don't need to tow five figures of weight with regularity, the gas engine is excellent, and you save a boatload of money. Sure, your fuel economy will be a bit lower with the gasoline option, but anyone buying this truck honestly doesn't care about fuel economy. The EPA doesn't even measure the fuel economy because it's so enormous, which is probably a point in its favor if you're the target market for this truck.

The exterior of the Denali HD is where things shine. The massive, enormous, gigantic, spectacular, monumental chrome grille is jaw-droppingly imposing. GMC says on its marketing website that it's "engineered to be large and in charge" and was "built big so you can tow big."

Subtle this ain't, and the best way to illustrate that is to park it next to the GMC Yukon Denali, which somehow looks diminutive next to its bigger brother. When something can make a Yukon look small, you know it's monstrously large.

Take a jog around the back of the Sierra HD, and you'll find GMC's terrific six-function MultiPro tailgate, which makes the bed easier to load and unload. While you're there, take a look at all the different cameras looking every which way to make your life easier when towing or just trying to fit into a parking spot at Costco.

The Denali HD comes standard with a slew of helpful safety and convenience features, including park assist, blind-spot monitoring, lane departure warning and automatic emergency braking. Notably missing is adaptive cruise control, which is a painful miss that GMC will hopefully rectify in the next update.

But where the exterior is excellent, the interior falls a bit flat. If you never looked at a competitor truck's interior, the GMC Sierra HD is fine — but it's just not up to snuff compared to what else is out there. The 8-inch screen is tiny compared to what you can get from RAM, but that's not to say it's a bad setup.

I'll just say that it'll be a good day for GMC truck buyers when the Sierra HD gets updated with the interior from the new Yukon.

That said, the dated interior hasn't seemed to slow sales. These trucks are flying off of dealer lots and with good reason. The Sierra HD is gorgeous and incredibly capable, and the hood scoop that's almost at eye-level with me when I stand in front of it is actually functional. That's not relevant to Sierra sales numbers, but I thought it worth mentioning because it's so cool.

The GMC Sierra HD is enormous, slathered in chrome, seats four in serious comfort, and is, for what you get, a relatively reasonably priced truck. Perhaps that's why GMC dealers are selling them as fast as they can get them from the factory.

The as-tested window sticker: