Purchased a 2016 Colorsdo…
Purchased a 2016 Colorsdo Crew Cab LT with the 2.8L diesel as a 16k mile certified vehicle from a GMC dealer in 2017. Loved the truck until 2018 with about 20k miles the trans started slipping and hard shifting. Took it back to dealer and they reprogrammed it. Problem continued, I took it back a few more times, they replaced the torque converter, a month later the truck was stuck in 3rd or 4th gear. Took it back again. This time the mechanic found wire chafing on the wire harness, not one. Not 2, but 7 of them. Repaired them and all my problems went away until 2025 and 95k miles, when towing a 7k trailer it started shifting into 3rd hard. I took it to the Chevy dealer and had the trans flushed. Have towed a 7k trailer over 4k now with no problems since the flush.
I was about ready to trade my Colorado in 2018 when it was just totally unreliable, I'm glad now that I did not, only other issue I've had is a phantom voltage draw on the battery I've not found yet but I put a remote battery disconect on it that cuts the battery off at under 11.5v if the truck is not running and zi just push a keyfob button hanging from my rear view mirror and pwr is restored. Not a fix but it works. This Midsize with the 2.8L diesel pulls a 7k enclosed 8.5ft wide tall trailer 70 mph down the highway pretty darn well occasionally, for regular daily towing of a load that size. I'd upgrade to a full sized 150 or 250 but for occasional such towing it dose the job well at about 12.5 mpg, 25 to 32 mpg when not towing.