New Update on our 2017 Colorado Diesel while towing.

New Update on 2017 Colorado. About a year ago I added full size 2500/3500 factory type extendable towing mirrors to the truck included some pics of it.
In mid May we took a trip to West Virginia pulling our new 22 ft. long, 8 ft wide 10.6 ft. tall camper weighing in at about 5,000 lbs loaded.
Another 500 lbs in the truck not counting my wife and I and two little munchkin dogs.
From Central Florida to North east W.V. Route 4 to Route 95 N. to Route 26 west to route 77 North. Then Route 81 North to our destination.
Drove speed limit 60 & 70 mph.
Truck pulled the camper as well as our 2016 High Country Silverado with 5.3 LS 1 engine and 8 speed trans. did.
Can't believe the power this little truck has when pulling those steep mountain grades.
It walked up every grade at the speed limit and a couple of times I stepped down on it to pass slower traffic like other R.V.'s and trucks.
Not one other truck our size pulling even lighter campers could hang with us on the hills.
We averaged 14 mpg on that stretch.
We dropped the trailer at our Sons place up on top of a mountain.
Then we put about 200 miles not towing going up into PA and MD.
Our total miles driven was 2,650 miles for the round trip.
We averaged 15.5 mpg for the whole trip.
The only thing that is different about this truck is the transmission temps while towing hard. It can run 225+ degrees F at highway speeds 70 mph + on hot summer days. Or while in heavy stop and go traffic in 90+ temps. It hit 237 degrees when we pulled and insane grade up to our sons place in 85 degree temps. That is the highest I've ever seen it go.
The last grade was so steep and gravel for about 3 tenths of a mile that I thought I would need 4 wheel drive, but it walked up it fine in 2 wheel drive.
It had no problem walking up that 2 mile or so insane hill terrain , basically off road driving to our Son's place.
The temp shot up on the last pull of just under a 1/2 mile.
I let it idle when we reached our destination and it cooled down pretty quickly.
GM say's that those are normal temps while towing. I think it's extremely high, but it never acted up or shifted funny.
I dropped the trans pan and changed the trans fluid when we finished the trip.
The fluid was fine, no burnt smell and still a nice red color not dark.
I refilled it with Amsoil ATF Fuel efficient fluid. That is what is called for the 6L50 six speed in the truck. The factory fluid is Dexron 6 synthetic.
It's the new style trans with no dipstick. You have to fill it from underneath thru a plug that is where the dipstick would be. Then go thru the gears and bring it up to a certain temp range and while running take out the drain plug on the pan. If no fluid comes out you have to add until it flows out.
Then you wait for it to stop flowing and start to dribble. Then put the plug back in.
We had 33,300 miles on it at the return of the trip.
I found two plastic covers totally blocking the air flow from the louver's just above the front spoiler.
I have a friend who is a G.M. Master Tech.
I asked about the covers and he said they were there to block air flow to the lower part of the radiator for trucks up North that need to get the trans temp up in winter.
The only trans cooler is a large finned area on the bottom part of the radiator.
And that is what those covers blocked ? Go figure!
I was thinking about adding an external cooler but it would be difficult to plumb in.
I haven't towed since removing the covers but it does run 10 to 20 degrees cooler running around in our Florida Heat 93 degrees and up.
We did get an honest 37 mpg on the hwy while in the semi mountain hilly Country around Hagerstown,MD and PA.
Strange that it gets better mpg in hilly country than it does in the flat land.
Really love this truck and the way it easily handled the trailer and load and was very stable while towing.
I have a Reese old style weight distribution hitch with twin cam anti sway.
The nature of this trailer was to sway some on uneven highways and heavy winds. The hitch solved that issue.
Truck and trailer was under the weight specifications for trailer load tongue weight and Gross Vehicle Combination Weight Rating.
Haven't had any issues with the truck, just a recall about DEF re gen stuff, Dealer did an update ECM re flash to address issues on some trucks that were re genning too often. We never had that issue.
I have only added a jug and a half of DEF fluid since owing it.
The dealer did the first 3 oil changes and topped off the DEF then. Not sure how much they added, but I wasn't paying for it LOL
I heard a rumor that GM isn't going to offer the diesel in the Colorado after next year.
Very sad. I wouldn't buy a new GM now just because of the Apple Car Play Radio system that comes in them now.
We have a 2019 Equinox with the Apple car play and we love the car and "
"HATE THE APPLE CAR PLAY SYSTEM".
Issues with our Android blue tooth phones working properly , unless it's an Apple Phone it won't work properly .
I refuse to buy another phone, especially an Apple $$$$.
Hope everyone stays safe and well and doesn't have a bout with the COVID.
These young jerks down here are running around in large groups with no Social distancing or mask or Common Sense.
They are getting it and spreading it like wildfire.
Sorry for such a long post, but just wanted to give our experiences with this truck. Thanks