The Denali designation has denoted GMC’s top-of-the-line trim package for decades now, and GMC sells more Sierra pickups than any other vehicle in its lineup by a wide, wide margin. So it makes sense that the minds behind GMC would want the top trim package of their best-selling vehicle to be something special, something that rises above the rest of the lineup by offering or debuting the latest and greatest features.

That seems to be the thought behind the 2017 GMC Sierra Denali 2500HD, slated to debut at GMC dealerships this fall. GM is playing mum on just what many of those features will be, but in a handful of teaser pictures release this week, the automaker does highlight the all-new functional hood scoop that it says “hints at what is beneath its bold new appearance.”

A little bit of visual inspection reveals a Duramax badge, meaning only one thing; a new diesel engine arrives this fall in the Sierra Denali 2500HD. Say goodbye to the current 6.6 liter Duramax diesel, which served customers well with its 397 horsepower and 765 lb-ft of torque (although they can make much, much more). A functional hood scoop is a rarity outside of a select few performance cars, which leads us to infer that the new diesel engine will be a heavy breather to necessitate this kind of additional equipment. In 2014, GM announced an investment of $60 million into the factory that produces the current Duramax motor.

Pricing and other features have yet to be released, leaving a lot of questions regarding the 2017 rendition of the Sierra Denali. Arguably, an all-new diesel motor is news enough, but we’re going to guess that a new suite of towing and hauling technologies could be on deck too. Whether or not the Allison 1000 transmission carries on with the new motor or not also remains to be seen.

Keep an eye out for more details as we approach the launch date later this year.