By all accounts, GM’s current full-size truck twins, the Chevrolet Silverado and GMC Sierra, are good trucks that are in many ways competitive with the sales-leading Ford F-150 and a fresh Ram 1500 that’s regularly nipping at the Bowtied truck’s tailgate. Considering the cashflow generated by the segment, though, it’s no surprise to see a refreshed version of the GMC Sierra testing with some light camouflage hiding some of the upgraded bits and pieces.

We’ll get to what we can see in just a moment, but first we’ll point out what we can’t see in these spy shots. What the GM pair really needs is a competitive interior. The current Silverado and Sierra are bridled by dashboards, door panels and instrument clusters that simply aren’t good enough when compared to their Ram and Ford competitors. We’ve spoken with a few designers from GM, and they are well aware of the criticisms that have been levied at their full-size truck duo, so we’d be shocked if there wasn’t a heavily revised interior lurking for the trucks’ next refresh.

Hopefully a future set of spy photos will give us a better look at what’s inside, because from this far-away, through-the-windshield look doesn’t give us much information. Will the Sierra share an interior with the redesigned Yukon? We’ll just have to wait and see, but suffice it to say that any improvement will be welcome.

Moving to the exterior, we can clearly see that the blocky, angular look of the current Sierra will continue through this refresh. A tiny look through the heavy tarp covering the truck’s face reveals a black plastic mesh grille, but we’re sure there’s plenty of chrome hiding under there, too. We’re left to wonder if that opening allows for a camera or radar to peek through, but rumors suggest GM’s well-regarded Super Cruise could be on the menu within the next few years.

We have no idea what’s under this test truck’s hood, but we wouldn’t imagine there will be much change to the current truck’s solid list of powertrain options. Here’s hoping the 3.0-liter Duramax inline-six diesel engine gets the cooling it needs to raise its tow rating to match its class-leading efficiency, because it’s arguably otherwise the best light-duty diesel offering in America. We know the automaker is working on electric powertrains, too, but we expect to see those debut first in the Hummer-branded truck that will be sold in GMC dealerships. We look forward to what we assume will be a rapidly incoming rush of spy photos as these trucks continue testing.

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