The sixth-generation, 2027 GMC Sierra's new headlight signature looks like a question mark as if to say: can you top this?The last-gen, light-duty Sierra 1500 truck wowed with its MultiPro tailgate, a feature that was soon followed by competitor copycats. New comes a new-gen pickup — highlighted by luxurious Denali and off-road AT4 trims that account for 50% of Sierra sales — that aims to standout for its comprehensive upgrade of all things, including exterior design, interior materials, bigger engines, more horsepower, more, more, more."This is an across-the-board upgrade," said Mark Dickens, GM executive chief engineer for full-size trucks and SUVs, in an interview. "There is not one particular thing that stands out. All things stand out for the 2027 truck."AdvertisementAdvertisementThe available articulated center display may beg to differ.2027 GMC Sierra 1500 AT4Jump into the Sierra and, with the push of a button, the infotainment screen will rise from the dash, revealing a secret storage space behind where passengers can keep valuable items and avoid cabin clutter. The high-tech feature is part of an available MultiPro console that anchors a working interior with all the comforts of a home office.InteriorThe MultiPro console is equipped with dual wireless charging pads, sculpted cupholders and a horizontal surface that can be configured into a mobile desk.Once on the highway, drivers can take their hands off the wheel with Sierra's standard Super Cruise self-driving system with three-year free subscription. With their hands on their knees and the pickup automatically changing lanes, drivers can get comfortable in plush leather materials and survey 60 inches of digital displays, a panoramic roof and premium touches liked forged wood trim.ExteriorAll this is wrapped in a typically handsome, muscular exterior styling that GMC calls "machine-precision design." Those question-mark lights? They are formed by upper, so-called C-clamp LEDs punctuated by mid-fascia headlamps. They feature available welcome and farewell animations and frame a bolder, more vertical grille.EnginesThe engine room has bite to back up the exterior's' bark.AdvertisementAdvertisementDisplacement grows to 5.7 liters and 6.6 liters in the two available sixth-generation small-block pushrod V-8 engines. Other engine options include a TurboMax 2.7-liter 4-cylinder powerplant and Duramax 3.0-liter inline 6-cylinder diesel stump puller. All engines are paired with a 10-speed transmission."The 2027 Sierra is an uncompromising, no-excuses truck," said Dickens. "Not only have we engineered these trucks to be fun to drive, but they'll provide customers with the versatility to haul with confidence, tow with command, head off-road with conviction and arrive to dinner in style. The Sierra represents one of the most advanced and rigorous engineering development and validation programs GM has ever executed; we've taken premium trucks to a whole new level."Emphasizing that new level are the pickup's signature Denali and AT4 trims that sit atop the four-trim lineup that includes Pro and Elevation models. They are sophisticated twins with different lifestyles.Denali UltimateThe pickup's flagship gets the 6.6-liter V-8, the most powerful naturally-aspirated eight-pot in class. It'll need that power to pull a condo-full of features to the country club.AdvertisementAdvertisementThe class-exclusive 16.3-inch articulating center display highlights 60 inches of screens, including a 11.5-inch passenger screen (with an articulating cover, natch) with media and entertainment functions.Behind the steering wheel is a 12.2-inch instrument display augmented by an enormous 15-inch head-up display which projects information onto the windshield, including speed, navigation and driver-assistance alerts. The system is run by Google Built-in for familiar, smartphone-like app and map navigationThe help see behind the 17-foot-plus long barge, Denali Ultimate is equipped with an 8.5-inch rear camera mirror. Other amenities include a 16-speaker Bose Premium Series audio system with front, headrest-mounted speakers.AT4XAdvertisementAdvertisementThis luxurious mud-slinger sits atop meaty, 35-inch Goodyear Wrangler Territory all-terrain tires for where the asphalt ends.Once off-road, new Multimatic dampers help manage high speed impacts as well as and rough rocks. Electronic-locking differentials in front and rear combine with the all-terrains for maximum traction..You'll know it by a unique, power-dome hood design, two-inch suspension lift and unique fascia.To cradle them against more violent tarin, passengers get enhanced seat bolstering while the driver maintains knee-room with flat-bottom steering wheel. Once belted in, passengers can bask in Timber Mahogany trim under a panoramic sunroof. For even more extreme off-roading capability, an AEV Edition package will be offered.AdvertisementAdvertisement"Denali Ultimate and AT4X solidify Sierra as the most powerful, most advanced and most luxurious trucks we've ever built," said Michael MacPhee, GM Global Vice President for GMC and Buick. "The next-generation Sierra is the truck all others will be measured against."The current, fifth-gen truck can tow up to 13,300 pounds and retails for between $40k-$90k. Details of the sixth-gen truck won't be available until production starts this fall in Indiana, Mexico, and Orion Township.Henry Payne is auto critic for The Detroit News. Find him at hpayne@detroitnews.com or Twitter @HenryEPayneThis article originally appeared on The Detroit News: Bold, high-tech GMC Sierra drops the mic