Towing our trailer to Mammoth, CA
We chose the Canyon because we liked its smaller size and its 7,000 lbs towing capacity. Coming from a two door hatchback the prospect of going to a full size truck seemed to far apart to grasp.
TLDR: The 2016 Canyon/Colorado v6 the engine can handle the 1995 even up some big grades but the transmission fluid temps rise pretty fast.
From the Canyon manual 1. Drive 500 miles before you tow anything (we drove 750) 2. Drive your first 500 towing miles under 50 mph and don't rev the engine too high (we kept under 50 except when going down hill we let it climb to 60)
The Canyon/Colorado V6 has 7,000 lbs of towing capacity with the towing package. Our Lance 1995 is close to fully equipped and was 4378 lbs out of the factory with 1 full propane tank. We added solar, 2 6v batteries, a second propane tank, a bike rack with 2 bikes and all our stuff. We're full timing in the Lance so we have a decent amount of stuff. The most cargo we can carry to stay within the trailer rating is 1322 lbs. That brings the total for the Lance to a max of 5700 lbs.
Then you add: 330# - Hitch ~300# - Running board and truck bed topper ~200# Cargo in the truck bed ~100# Passenger aka my wife
6630# - Total if we have the trailer at max cargo
6000# - Our likely total - still at 86% of our max towing capacity.
So we decided to climb 6%+ grades up 3000 feet in 101 degrees on brand new black asphalt to test it out (more like by happenstance)... It was a bit rough. We have a digital read out on the transmission fluid temp on the dash. It jumped from about 170F to 220F about halfway up the first big hill. We pulled over to let the truck cool down, leaving the engine on to keep the transmission cooling going. It took about 15 minutes to cool down to 180F so we could keep going. (Note we had not issued with the engine temp).
We tried it one more time like that with grey at 1/3 tank (not a good idea) up 395 to Mammoth. Had to stop 3 times to get up that hill without going above 210F for transmission fluid. When we took off up the hill we knew what we were getting ourselves into and budgeted time to stop on the side of the hill to let the transmission cool down. Worth it right...?
Arrowhead Lake, Mammoth
In Mammoth we decided to cut weight. Threw out a bunch of stuff we had two of and things we hadn't used yet and didn't feel like we'd use. 1 large black trash bag that was probably only 50 pounds but it made us feel better. Plus our neighbors took a few things and the camp host took the rest to a local thrift store.
We kept the golf clubs and few other things for now to see how we do in cooler temperatures and to see what we actually use in our first month. Not quite ready to really downsize for just another 50 ish pounds so... we went for an evening walk at Convict Lake.
Convict Lake, Mammoth
Leaving Mammoth a few days later we had another 6% grade 2,500 foot climb. (We are using this great app called inRoute, pic below). This time it was only 75F out and we had empty tanks (a little in the potable tank). The transmission fluid stayed under 205F as we reached the top. Felt a lot better.
App Called inRoute - shows Elevation
Tips - run the RPMs higher and down shift when going up hills. Try not to shift too often and consider putting it into manual to have better control. Empty all your tanks. We even started taking some hills at half a tank of gas when we knew there was a gas station on the other side. The gas tank is over 20 gallons.
According to a GMC towing expert our dealer directed us to:
"The 3.6 Canyon with Z82 is the perfect combo for towing your customer's 5000lb trailer, nicely within the 75% rule for towing. The V6 comes standard with an external transmission cooler and engine oil cooler. I don't see a need to add additional coolers for this combination.
Transmission temperatures should average between 185-195 degrees under normal, non towing conditions. During sustained towing, including mountainous terrain, temperatures between 195-220 are common and not a concern. If transmission temperatures go above 230 I would start to be concerned, especially if they stay high and refuse to come down."
I hadn't heard about the 75% rule. But we've gone over a few big grades since our first few mishaps and did much better when the outside temperatures were in the 80s and below.
Should we have gone with the v4 turbo diesel for $4K more? Maybe but I'm still happy with the v6 gas now that we're getting used to it. I was told the 7,700# towing capacity diesel was better for pulling from the start 0-10 mph. But if I was told it would have taken hills much better we might have given it more consideration. As others have pointed out - the added maintenance costs for diesel out weight the mpg savings that the diesel has over the gas truck. The $4K extra won't pay back but might give you some more piece of mind. All that said we haven't tried towing with the diesel so this is just speculation.
A few more engine details (when towing): When climbing: 3rd Gear - 3-3.5k RPMs can keep us at 45-55. But when the hill gets too steep we drop to 2nd. 2nd Gear - 4K-5k RPMs can keeps us at 40-50 if we have momentum or 4K will keep us at 30ish from a slow start. 1st gear - 4-5k we had to drop to 1st at slow speeds going up big hills
When cruising: 3rd gear: 2.5-3k rpm around 50-55 4th gear: 2-2.5k rpm around 55-60 (most of time when cruising) 5th gear: 1.5-2k rpm - usually use this when I'm doing a long slight downhill. Don't usually get into 6th when towing.