Since my last update we have added another 4,000 km to the odometer on our 2019 Canadian Truck King Challenge winner – the Sierra Denali. We now have a total of 15,000 km on the truck.
I wish it was more as many readers won’t consider this very “long-term”. However short of buying the Denali and reporting on for the next 5 years – this is the best we can do. I hope readers will agree that it certainly beats the reviews generated by most writers who drive the truck for a week and never even tow with it.
Instead we’ve been driving it for three months now and continue to driveit daily. There have been no mechanical issues to date, instead we’ve now had enough seat time to have found those small features that we really like and a few habits the truck has that we don’t. But more about those later.
Today I want to go into its towing ability and the systems that the truck offers to assist drivers with that task. Over the past two months the Denali has been doing a lot of towing for us. Luckily our having it to test just happened to coincide with two major family moves. My son Matthew moved from Georgetown (my basement actually) to his new house in Victoria Harbour, on Georgian Bay, ON. My mother, after 50 years in her Brampton home is selling and temporarily taking up residence in the digs vacated by Matthew – till her seniors’ condo is ready later this year. So, with all these pieces in motion, I am the chief mover and the Sierra is at the center of it all – well it and my trailer.
The trailer I’ve been using for these moves is an enclosed four-place snowmobile trailer. At 27-feet long with a full-wall ramp door at the rear it’s ideal for the chore. The twin-axle trailer weighs around 4,000 lb empty and will carry another 4 to 5,000 lb of cargo. This is a good match for the Sierra; a fact I can verify by simply checking the weight sticker on the truck’s door jamb.
This weight sticker is worth mentioning right off as it is a feature unique to GM. On each GM truck (Chevrolet and GMC) the factory places a label specific to that truck. Based on the build (by VIN number) the company calculates and clearly states the relevant weight information. And, in the case of my truck those numbers are:
- GVWR – 3,221 kg / 7,100 lb
- GCWR – 6,804 kg / 15,000 lb
- GAWR – 1,724 kg / 3,800 lb
- Max Payload – 674 kg / 1,486 lb
- Max Tongue – 422 kg / 930 lb
- Curb Weight – 2,547 kg / 5,614 lb
Curiously the number they don’t print is Max tow weight. However it’s an easy calculation. Take the GCWR minus Curb Weight = 9,386 lb. That’s the max tow rating. And, that number is 100% accurate. It’s not a guesstimate – or what my buddy told me I could tow – or what the latest over-the-top TV truck commercial claims. No; it’s a factory number based on my one-off, uniquely built truck – and it’s SAE J2807* approved. (*This is a tow testing protocol that is agreed on by all the manufacturers. It was conceived and endorsed by the Society of Automotive Engineers).
I’ve talked about the 6.2L V8 with the Dynamic Fuel Management system and its performance previously. What I want to add today are comments on the 10-speed automatic transmission. First, the power of this combination is more than ample in any situation – including while towing up to the max allowable number.
Now, with that much trailer strain on the powertrain you might think you’d notice some rougher shifting or perhaps a hesitation as the DFM engages or drops out. There is none.
As proof – I’ve passed traffic, foot to floor, with my loaded trailer in tow and there isn’t even a squeak from these systems. It is obviously engineered to the point where the weight has no adverse effect on its overall powertrain performance even under severe stress.
So, these observations cover the weight and the power questions that come with a new truck; and at one time, (back in the dark ages) this is all a truck owner cared about. Well, that and a good set of mirrors. Today the towing landscape has changed. Thankfully though, it’s for the better.
Anyone who’s been towing for a while knows that the maximum tow weight limits on half-tons have doubled in the past twenty years. So while the manufacturers continue to build these larger trucks with more capacity they have also (in the last five years or so) realized that they must add “driver assist features”. These are not to be confused with a convenience feature like a power-seat. Driver assist features are there to help you safely manage these new higher load limits. I want to look at these now and comment on my experiences.
- Heads-up display: Projected onto the windshield, this 3×7-inch multi-colour display conveys information to the driver. The speed readout is the main focus; but it also projects Nav, phone and infotainment settings. So, why do I include this in a list of towing assist features? Because as the driver you are being fed information without ever having to take your eyes of the road. Anything that cuts down on distractions is a safety feature and while towing you can’t afford to be looking anywhere accept at the road. In future I expect all manufacturers to mimic this innovation.
- Adaptive Ride Control: This electronic system mimics an air-ride suspension as it reacts to road conditions and driver inputs. It adjusts shock damping in milliseconds for optimal ride comfort. What the brochure doesn’t say – but which I noticed right away – is that it also reacts to the weight of a hitched trailer. While hooking up I could hear it try to counteract the rear-end drop as the trailer weight settled on the hitch. It brought it back up somewhat – not to complete level – but I felt that the added resistance in the shocks certainly helped the attitude of truck and trailer.
- Tow-haul – Adjusts the shift points in the transmission to maximize torque – particularly from a standing start. This is a system that’s been around for a while, but it’s still important to manage your load. It’s accessed using a rotary dial at the top left of the dashboard. Turn the dial to it and select. It’s lumped in with the various “ride” settings that switch up the Adaptive Ride Control feel. It took me a while to find it the first time I looked and I also noted that it has to be reset each time the truck is shut off for more than an hour. I prefer the old “button” on/off control that I could clearly see on the dash.
- Cameras – If you’ve towed with only mirrors for visibility you know that there are huge blind spots around a truck/trailer combination. This Denali however offers four cameras that virtually eliminate those vision dead- zones. These even stitch images together creating a virtual surround- vision camera – that provides a bird’s eye view of your truck. Also camera’s in the side mirrors help see down the full length of the towed combination. A camera on the nose of the truck shows images of potential obstacles –as does the rear mounted camera. This one in particular is the one every driver learns to love right away. With it you can back your ball right under the trailer coupler the first time. The screen has guidance lines on it – that bend as you turn the steering wheel guiding you precisely to the coupler. A magnifying feature (which you activate on the centre stack screen) lets you zoom in as you reverse those last two-inches. Once you experience the various camera views the system offers you’ll wonder how you ever managed with mirrors alone.
- Pro-Grade trailering system – This includes an in-vehicle app as well as an optional myGMC smart phone application. There are several trailering information features within this app – but the single best one is the trailer light test. This chore, (checking your trailer lights) that everyone has done a zillion times after hooking up, is made so easy with the app. The old school method required a helper or if you were alone – turning on the lights – walking to the back of the trailer to look – then walking back to flip on the signals – then walking back to check again – and so on. Now, with the app, you stand at the rear of the trailer and cycle through the lights without ever having to take a step. Brilliant.
Other functions include custom profiles for up to five trailers. These files can keep track of mileage, tire pressure, maintenance needs and set trailer brake gain settings.
There is ever a pre-departure checklist that offers a step-by step illustrated guide to the connection process. Obviously this is great for the novice – but for those of us who tow all the time, well – just remember that veteran pilots consult a written checklist before every flight. We all forget things.
To sum up I have to say that this GMC Sierra Denali is a competent and comfortable tow vehicle. Even at its load limits it feels good on the road and with the 6.2L V8 and 10-speed transmission it’s powerful enough in every driving situation. I’ve towed well over 1,000 km in the past three months and I’m satisfied with its performance.