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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 considering new powertrain options for large SUVs

Aside from the new General Motors offerings, there's not a whole lot of action going on in the fullsize SUV segment. That doesn't seem to be stopping GM from pushing the envelope in the market as Automotive News is reporting that the automaker is looking to introduce some new powertrain options into the Chevy Tahoe (and Suburban), GMC Yukon (and Yukon XL) and the Cadillac Escalade - all have been redesigned for the 2015 model year.
Now, we already know that GM and Ford are collaborating on nine- and ten-speed transmissions for a broad range of applications (including the big SUVs), but this new report says that GM is also considering other options as a way to one-up the competition and, of course, to optimize fuel economy. AN quotes Jeff Luke, executive chief engineer for GM trucks, as saying that "interesting powertrain technologies" are coming including a return of a hybrid SUV and possibly even a diesel engine. Although it sounds like the latter could come down to how customers respond to the 2014 Jeep Grand Cherokee EcoDiesel.

Leak reveals GM's 2017 heavy duty diesel trucks to get 910 lb-ft of torque [UPDATE]

UPDATE: Chevrolet officially announced specs for the 2017 Silverado HD and the rumors were true. The truck's new Duramax 6.6-liter turbo-diesel V8 puts out 445 horsepower and 910 pound-feet of torque. Chevrolet says the new motor produces 19 percent more torque and 12 percent more horsepower, while producing 35 percent fewer emissions. Overall, the new engine is a big improvement over the current motor, which generates 397 horsepower and 765 pound-feet of torque. According to Truck Trend, GM's newest heavy duty pickup trucks will pick up quite a bit more power and torque. The publication spotted a recent GM Powertrain ordering catalog that had the engine specs for the 2017 model year and managed to get some screenshots before the catalog was taken down, and they can be viewed here. The screenshots revealed that the 6.6-liter turbodiesel V8 powering the Silverado and Sierra heavy duty models will boast 445 horsepower and 910 lb-ft of torque. This is a substantial gain over the current models' 397 horsepower and 765 lb-ft of torque, and as Truck Trend points out, it exceeds the Ford Super Duty line's horsepower output of 440, but comes short of the 925 lb-ft rating. Truck Trend credits part of this output gain to the new intake system GM will introduce on the 2017 heavy duties. The intake gets 60 percent of its air from a scoop on the hood, with the other 40 percent coming from behind one of the front fenders. GM doesn't reveal horsepower figures in the press release about the scoop, but it does say the cooler air helps with maintaining the engine's output, and that the scoop does produce a ram-air affect, providing more air at speed. As we know, more air plus more fuel equals more power, but there's likely more to the power increase in this engine than only the intake. Related Video: News Source: Truck Trend via MSN Chevrolet GM GMC Truck Diesel Vehicles