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Torque time | 2017 GMC Sierra HD First Drive

It's not the truck that counts, it's how you use it. It's the heavy stuff you fit in its bed or the extremely heavy stuff that gets hooked up to the tow hitch. The ATV, the Jet Skis, the trailer with more square footage than a Greenwich Village apartment. Perhaps you need to get Seabiscuit or, uh, Mr. Ed to wherever they need to gallop next. In our case, there's a pair of very serious-looking snowmobiles perched atop the bed of a GMC Sierra. They spread out as wide as the extended tow mirrors, and their back halves are dangling precariously beyond the truck. Sterling Archer would be giddy; I'm a little nervous. But only because canyon roads and wide vehicles with a high center of gravity go together like peas and custard. The added weight is no sweat at all. That's because this is the 2017 GMC Sierra HD Denali, a truck with the sort of enhanced power, torque, suspension, and stopping capability expected of a heavy-duty pickup. And for this year, the power and torque get a serious bump courtesy of a new 6.6-liter Duramax turbodiesel engine reengineered from almost the ground up with 90 percent new parts. It's quieter and more efficient and it emits less, while most importantly producing 445 horsepower and 910 pound-feet of torque. That's up from 397 and 765, respectively. Chevy fans will note that the same engine is also available in the updated 2017 Silverado HD. Now, for those keeping score at home, that horsepower is best-in-class but the torque number still falls short of the new Ford Super Duty and its Power Stroke diesel V8's 925 lb-ft. Aw shucks. For the record, GM's engineers didn't seem too concerned that they weren't able to eke out an extra 16 torques just to say they're No. 1. "We wanted to first meet emissions and then deliver the maximum horsepower and torque we could, and deliver it over the widest usability range possible," said chief engineer Eric Stanczak. And let's be honest here, 910 pound-feet is herculean, and once again, a jump of 145 lb-ft. Or one Subaru Impreza's worth. Or 110 more than the best Ram can do on a 2500, and its Cummins turbodiesel's 800 pound-feet was eye-popping not too long ago. (The Ram 3500 maxes out at 900 lb-ft with the right transmission.) Ah, but here's the rub. That Cummins-equipped Ram 2500 can still tow more weight according to SAE-compliant measurements – 17,510 pounds for a Ram crew cab with a short bed versus 13,000 in the similar Sierra 2500. The Ford F-250 can manage 15,000.

GM exploring ways to raise half-ton Duramax diesel tow rating

Lots of truck owners cheered when GM announced fuel economy numbers for the 2020 Chevrolet Silverado with the 3.0-liter Duramax diesel inline-six. Even after Ram let loose its EPA mileage ratings for the 2020 Ram 1500 EcoDiesel, the Chevy oil-burner still took the trophy. The victory was years in the making, GM engineers spending an entire four-year development cycle refining the LM2 Duramax to increase mileage. The tradeoff, as well all know by now, is towing; the Duramax in half-ton duty pulls a maximum 9,300 pounds in the Silverado. Rivals across town can do more, the Ford F-150 PowerStroke rated at 11,500, the Ram 1500 EcoDiesel game to pull 12,560. GM engineer John Barta told Muscle Cars & Trucks that more hauling chops could be on the way, explaining, "We’re actually looking at upgrading some of the materials around (the engine bay) to see if we can maybe raise our tow rating." Engine bay materials are at issue due to thermal complexities underhood. John Barta, GM's assistant chief engineer of diesel engine controls, said the Duramax's inline-six configuration allowed engineers to get emissions hardware like the combined selective catalytic reduction, diesel oxidation catalysts, and diesel particulate filter unit closer to the engine, where it heats up quicker, getting emissions down quicker. But that filter puts another heat source in those confines, enforcing a cap on the tow rating to keep the engine and other systems from overheating. "If you look under the hood," he said, "youÂ’ll see a significant amount of silver ‘moon tapeÂ’ around to make sure things arenÂ’t getting overheatedÂ… if we were to go up in higher towing, which we can, we start impacting the possibility of deteriorating some of the components.” There isn't much space for more grille, so swapping for a better grade of "moon tape" or a different kind of material could reduce engine bay heat, extracting a higher tow rating in the process.  It's important to note a point Barta's been making for months about the Duramax figures, though. "Even though itÂ’s nice to brag about big numbers, in reality, light duty customers are not towing that large with their trucks," and, "We do know that (95 percent) of our light duty customers donÂ’t tow over 9,000 pounds." On our First Drive of the 2020 Silverado diesel we called out the tow rating, but emphasized that the Chevy and GMC have more important challenges to overcome.

GMC Hummer EV will be unveiled during the World Series and 'The Voice'

A big-time vehicle reveal deserves a prime-time multi-platform debut. At least, that seems to be the opinion of the folks tasked with reintroducing the American public on October 20 to the Hummer nameplate, this time affixed to pickups and SUVs that also wear General Motors' "Professional Grade" GMC badge. And instead of a standalone brand with dealerships full of gas-guzzling off-road beasts, this new, kinder, gentler and fully electric Hummer won't sip any gas at all. The debut will take place across several channels. As has been the de facto process during the pandemic, the event will be streamed online. But — taking a page from the reveal of the Ford Bronco this past July — it will also be witnessed by watchers of the World Series on Fox and "The Voice" on NBC (at least those who are watching live and aren't skipping commercials). Interestingly, according to The Detroit News the television segments will be spread across multiple commercial breaks as sort of a mini film. Naturally, we'll be covering the unveiling live right here on Autoblog, and we'd argue that's the best place to see it all unfold (we admit we may be biased). In any case, no matter where you watch you'll be treated to a host of details about what GMC is calling "the worldÂ’s first super truck." We know it'll boast 1,000 horsepower, go from 0-60 in around 3 seconds, have the next generation of GM's Super Cruise autonomy technology, have removable roof panels and be able to crab walk. Sounds pretty super to us, and we're looking forward to the full reveal in just a couple of weeks. See you then. Related Video: