Smooth, Powerful Diesel Performance
The 2021 GMC Sierra 1500 Duramax 4WD Crew Cab AT4 CarbonPro showed-up in my driveway and the neighbors took notice. Only of a few of them would be considered “truck people”, so their comments were interesting. I heard how nice it looked, how it wasn’t overly garish and, while big, it wasn’t too big. This last one was curious as this truck is pretty darn big! But maybe since the predominant vehicles on the road these days are midsize to large SUVs, a big truck really isn’t so big.
Power and Torque and Fuel Sipping
Clean Fleet Report recently drove the 2021 GMC Sierra 1500 4WD Crew Cab AT4, powered by a 3.0-liter Duramax turbodiesel engine. The numbers of 277 horsepower and 460 pound-feet (lb.-ft.) of torque, while mated to a 10-speed automatic transmission, only begin to tell the story of smooth performance with plenty of grunt when needed. There is a low diesel rumble upon start-up that becomes a nice note when accessing the ample torque to get off the line, but then purrs at freeway speeds. Stand next to the hood when the engine is at idle, and you will be amazed at how quiet it is. About that torque: you get full max 460 lb.-ft. at a very low 1,500 rpm. This means that when you are towing up a grade, it will pull strong and still deliver good fuel economy. Not enough can be said about how excellent the General Motors 3.0L Duramax turbodiesel is.
Weighing in at 5,640 pounds, the Sierra 1500 AT4 has a maximum payload of 1,810 pounds and can tow 8,800 pounds. These numbers are a bit lower than competitor trucks, but the trade-off is better fuel economy in exchange for less payload and towing.
Fuel economy for the 3.0-liter Duramax turbodiesel is EPA rated at 22 mpg city/26 highway/24 combined. In 235 miles we averaged 25.2 mpg, but on a 100-mile all-freeway run with the adaptive cruise control set at 65 mph, we got an impressive 29.8 mpg. When fully loaded or pulling a trailer, mileage numbers will be less. But nudging 30 mpg is impressive, which was aided by the engine stop/start system, which shuts off the engine rather than idling. Fuel economy numbers reported by Clean Fleet Report are non-scientific and represent the reviewer’s driving experience using the dash gauge computer. Your numbers may differ.
On the Road: Smooth and Responsive
The Sierra 1500 AT4 was comfortable out on the road, where it shines on long distance trips. The even acceleration, with very useable torque coming on at 1,500 rpm, made it a breeze to drive in-town or on the freeway. Even under the most severe road conditions, the Sierra’s ride was never rough with little road noise, harshness or vibration transmitted into the cabin. Aiding the driving is GMC’s Stabilitrak stabilizer control.
There was no learning curve with the hydraulic-assisted brake system that included four-wheel anti-lock discs and electronic stability assist, which brought the truck to confident stops. The electric-assisted steering had good road feel with responsiveness and little body roll in most cornering situations.
Clean Fleet Report didn’t have the opportunity to do any off-roading, nor did we encounter any wet or sloppy weather during our week driving through Southern California. But from the standard and optional equipment, we can tell the Sierra AT4 would handle pretty much whatever you threw at it, short of serious rock crawling. Our Sierra AT4 had the X31 off-road suspension, a two-inch lift, Rancho monotube shocks, skidplates and mud-rated Goodyear Wrangler DuraTrac 275/65 tires mounted on 18-inch machined aluminum wheels with dark grey accents.
The dash has controls for 2WD, 4WD and Auto 4WD. The first two are self-explanatory, but the latter is a nice feature as it automatically sends torque to the front tires if the system senses any tire slippage. This is not an AWD system, but pretty close, that offers a sense of security and confidence in slippery or sloppy road conditions. Our Sierra AT4 also was equipped with the trailering package that included a trailer brake controller, jackknife alert and trailer electrical hook-ups.
Upscale Interior
The well laid-out interior uses upgraded materials, many of which rival the high-end GMC Denali. Clean Fleet Report’s Sierra AT4 had an attractive two-tone interior of Jet Black with Kalahari accents. The leather-trimmed seats were firm and comfortable with the heated, ventilated, 10-way power front buckets (the driver gets memory) separated by a center console large enough to hold a laptop. The 60/40 folding rear seat, with storage compartments in the back and under the seat, was heated for the outbound passengers and can easily hold three full-size adults. The power rear sliding window and power sunroof were nice features, along with the wireless charger for mobile phones, dual zone climate control and leather-wrapped, heated steering wheel with audio and cruise controls.
The standard rear vision camera provided clear, wide images on the 8.0-inch color touchscreen monitor with up-to 15 camera views, including surround vision, two trailer and one bed view. The screen also is home for navigation and the seven-speaker Bose Premium Sound System with FM/HD AM radio, wireless Apple CarPlay, Android Auto and SiriusXM. Bluetooth handled voice communication for hands-free phone, audio and OnStar. Multiple front and rear USB ports and an auxiliary power outlet kept everything charged and ready to go. The dash gauges were easy to read, and the radio passed the Clean Fleet Report minimum driver safety test as it had volume and channel selection knobs. About those radio knobs and the climate control wheels: they are constructed using a cheap-feeling chromed plastic. These were the only drawbacks to this fine interior, but certainly not a deal breaker.
A note regarding OnStar: a simple push of a button connects you with a friendly General Motors representative to handle emergencies, directions and general assistance to make your driving experience safer and more enjoyable. This is one area where GM is the industry leader, and after the trial service plan expires, it is well worth renewing.
Another convenience was the 4G LTE Wi-Fi Hotspot that can connect multiple devices and has a 50-foot range. If you are packing the family for a road trip, then the Wi-Fi is a must to keep the backseat crew happy, occupied and quiet.
Bold Design
Clean Fleet Report was driving the Sierra 1500 AT4 with the CarbonPro trim line. CarbonPro designates the box is made of weight-reducing carbon fiber where the standard steel inner panels and floor are replaced with a lightweight, purpose-designed carbon fiber composite that offers best-in-class dent, scratch and corrosion resistance. This is a big step in box design, so expect to see this material used soon elsewhere on other General Motor’s trucks. The CarbonPro package was enhanced by the Onyx Black paint with a tasteful use of chrome and red tow hooks poking out from under the front fascia. The grille, with its LED reflector high-intensity headlights, C-shaped daytime running lights and fog lights did not present as massive as front ends found on other trucks. The power-adjustable and heated exterior mirrors provided excellent rear visibility and were quiet going through the wind.
The Sierra 1500 AT4 came with the GMC MultiPro tailgate, which has six functions that make it extremely useful. Excellent access to the box is made possible by the tailgate that drops down in one piece and has two built-in load stops; has a section that drops so you can stand even closer to the box and your cargo; a section that drops to create a full-width step that can handle 375 pounds; and, lastly, for a cool factor, the gate has a built-in Kicker audio system that runs off a flash drive.
The box has LED lighting and 12 fixed tie-down rings with the corner rings rated at 500 pounds. The 120-volt power outlet is a useful feature, as was the running board step and the corner steps on the rear bumper outer edges. The tailgate can also be power-operated down by the key fob or a piano switch on the dashboard.
Safety and Convenience
The 2021 Sierra AT4 has front and side curtain airbags, electronic stability control with rollover mitigation, trailer sway control and hill start assist and a tire pressure monitoring system. The standard advanced driver assistance systems (ADAS) include lane change and blind zone alert, rear cross traffic alert and front and rear parking assist. The Driver Alert Package II ($1,095 option) included automatic emergency braking and forward collision alert, lane keep assist and departure warning, front pedestrian braking and a vibrating driver’s seat which lets you know something about your driving isn’t just right. Also available on the Sierra was the Teen Driver safety system, which helps inexperienced drivers develop safe driving habits.
The multi-color 15-inch diagonal head-up display was both a convenience and safety feature. Clean Fleet Report feels a HUD should be standard on all vehicles if auto manufacturers and the government are serious about reducing distracted driving.
To aid in rear visibility, the rear view mirror can act like a conventional mirror, but also as a high definition camera. The camera mode takes some getting used to, as the perspective is different, showing a wider view. I found it especially helpful when parking, used in conjunction with the multiple rearview cameras.
The 2021 Sierra has earned a US Government NationalHighway Traffic Safety Administration (NHTSA) 4 out of 5 Stars Overall Vehicle Score. The Insurance Institute for Highway Safety (IIHS) has given the Sierra an overall Good rating.
Pricing and Warranties
Clean Fleet Report’s 2021 GMC Sierra 1500 Duramax 4WD Crew Cab AT4 CarbonPro had a base MSRP of $53,800. With $10,125 in options and the $1,595 destination charge, the total came to $65,520.
The 2021 GMC Sierra comes with these warranties:
- Bumper-To-Bumper – Three years/36,000 miles
- Powertrain – Five years/100,000 miles
- Roadside Assistance – Five years/100,000 miles
- Corrosion – Three years/36,000 miles
- Rust-Through – Six years/100,000 miles
- Maintenance – First Visit
Observations: 2021 GMC Sierra 1500 Duramax 4WD Crew Cab AT4 CarbonPro
Is the 2021 GMC Sierra 1500 Duramax the best 1500 pickup on the market? Talking with “truck guys and gals” and reading truck forums, it seems to be near or at the very top. Obviously, if you need a truck for a specific reason, say towing a large weight or the ability to go serious rock climbing, then the 2021 GMC Sierra 1500 Duramax 4WD Crew Cab AT4 CarbonPro may not be for you.
However, if you are looking for comfort, versatility, great looks, a very accommodating and large interior, some innovative features and, of course, excellent fuel economy, then this may be the truck for you.
It used to be that diesel engines were only found in heavy-duty trucks. No more, as they are becoming more prevalent. The 3.0L Duramax turbo diesel is the most efficient engine offered in any GMC Sierra pickup. It falls between the 4.3L V6, 5.3L V8 and 6.2L V8 gasoline engines, offering a smooth power plant that can flirt with 30 miles to the gallon on the highway.
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Story by John Faulkner. Photos by John Faulkner and GMC.
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Disclosure:
Clean Fleet Report is loaned free test vehicles from automakers to evaluate, typically for a week at a time. Our road tests are based on this one-week drive of a new vehicle. Because of this we don’t address issues such as long-term reliability or total cost of ownership. In addition, we are often invited to manufacturer events highlighting new vehicles or technology. As part of these events we may be offered free transportation, lodging or meals. We do our best to present our unvarnished evaluations of vehicles and news irrespective of these inducements.
Our focus is on vehicles that offer the best fuel economy in their class, which leads us to emphasize electric cars, plug-in hybrids, hybrids and diesels. We also feature those efficient gas-powered vehicles that are among the top mpg vehicles in their class. In addition, we aim to offer reviews and news on advanced technology and the alternative fuel vehicle market. We welcome any feedback from vehicle owners and are dedicated to providing a forum for alternative viewpoints. Please let us know your views at publisher@cleanfleetreport.com.
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