The redesigned, next-generation Sierra HD's exterior is more visually distinguished from the Sierra 1500. Aside from its roof, which is shared with the light-duty Sierra, all other visible elements are unique to the work-focused HD truck. The standard engine is a 401-hp, 6.6-liter V8 with a six-speed transmission. A 445-hp, 6.6-liter turbodiesel V8 engine with a 10-speed transmission is also available.
Alerts
There are 6 recalls on this vehicle. Learn More.

Road Test Results

Performance
Acceleration Acceleration Acceleration tests are conducted on a smooth, flat pavement straightaway at the track. Time, speed, and distance measurements are taken with a precise GPS-based device that’s hooked to a data-logging computer.
NA
0 to 60 mph 0 to 60 mph (sec.) The time in seconds that a vehicle takes to reach 60 mph from a standstill with the engine idling.
Transmission Transmission Transmission performance is determined by shifting smoothness, response, shifter action, and clutch actuation for manual transmissions.
NA
Braking Braking The braking rating is a composite of wet and dry stopping distances and pedal feel. Braking distance is from 60 mph, with no wheels locked.
NA
Emergency Handling Emergency Handling Several factors go into the rating, including the avoidance maneuver speed and confidence, as well as how the vehicle behaves when pushed to its limit.
NA
Comfort / Convenience
Ride Ride Our expert judgment of how well the suspension isolates and absorbs road imperfections and how steady it keeps the body on various road surfaces.
NA
Noise Noise Our expert judgment of the vehicle's interior noise level in everyday driving.
NA
Front Seat Comfort Front Seat Comfort Our judgment of how comfortable the front seat is for drivers of various heights.
NA
Rear Seat Comfort Rear Seat Comfort Our judgment of how comfortable the rear seat is for two passengers to sit across.
NA
Interior Fit and Finish Interior Fit and Finish An expert evaluation of the interior quality and craftsmanship.
NA
Trunk/Cargo Area Trunk/Cargo Area Our rating is based on the amount of luggage or cargo space that a vehicle has in the trunk or cargo area.
NA
Fuel Economy & Emissions
Fuel Economy Fuel Economy We perform our own fuel-economy tests, independent of the government's often-quoted EPA figures and the manufacturers' claims. Using a precise fuel-flow measuring device spliced into the fuel line, we run two separate circuits to represent city and highway consumption.
NA
CR's Overall Mileage CR's Overall Mileage CR's overall mileage is a composite of measured fuel usage on a prescribed city course and highway cruising; and CR's 150-mile test trip of mixed driving, if tested. In recent road tests, we've discontinued the 150-mile trip test.
CR's City Mileage CR's City Mileage Measured fuel usage on a prescribed city course.
CR's Highway Mileage CR's Highway Mileage Measured fuel usage on a prescribed highway cruising.
Annual Fuel Cost Annual Fuel Cost The cost and amount of fuel used in 12,000 miles and is calculated from CR's overall mileage.
Greenhouse Gas Greenhouse Gas The Greenhouse Gas Rating represents the amount of carbon dioxide the vehicle emits compared to other vehicles of the same model year. This score from the EPA ranges from 1 (worst) to 10 (best).
NA
Smog Rating Smog Rating The Smog Rating represents the amount of health-damaging and smog-forming airborne pollutants the vehicle emits compared to other vehicles of the same model year. This score from the EPA ranges from 1 (worst) to 10 (best).
NA

Owner Reports

Worse Better
Reliability History Reliability History The reliability charts are based on responses on hundreds of thousands of vehicles from our latest Annual Auto Survey. Consumer Reports subscribers reported on any serious problems they had with their vehicles during the past 12 months that they considered serious because of cost, failure, safety, or downtime, in any of the trouble spots included in the table below. The results are presented relative to the average model that year. Extra weight is given to the more serious areas such as major engine or transmission problems. Based on this data and further analysis, we predict reliability for the latest year. N/A indicates that we did not receive a large enough sample size to provide data for a specific year. An X indicates that the vehicle was not manufactured for a specific year.
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
NA
2011
2012
NA
2013
2014
2015
2016
2017
2018
2019
2020
Reliability Trouble Spots
Engine Major Engine Major Engine rebuild or replacement, cylinder head, head gasket, turbo or supercharger, timing chain or timing belt.
NA
Engine Minor Engine Minor Accessory belts and pulleys, engine computer, engine mounts, engine knock or ping, oil leaks.
NA
Engine Cooling Engine Cooling Radiator, cooling fan, antifreeze leaks, water pump, thermostat, overheating.
NA
Transmission Major Transmission Major Transmission rebuild or replacement, torque converter, clutch replacement.
NA
Transmission Minor Transmission Minor Gear selector or linkage, leaks, transmission computer, transmission sensor or solenoid, clutch adjustment, rough shifting, slipping transmission.
NA
Drive System Drive System Driveshaft or axle, CV joint, differential, transfer case, 4WD/AWD components, driveline vibration, traction control, electronic stability control (ESC), electrical failure.
NA
Owner Satisfaction Owner Satisfaction To learn about satisfaction, CR has collected survey data from our annual survey on more than half a million vehicles. Our subscribers provide great insights into their satisfaction by answering one simple question: If they had it to do all over again, would they definitely buy or lease the same model? In addition, respondents also rate their cars in six categories: driving experience, comfort, value, styling, audio, and climate systems. N/A indicates that we did not receive a large enough sample size to provide data for a specific year. An X indicates that the vehicle was not manufactured for a specific year.
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
Driving Experience Driving Experience Includes acceleration and handling
Comfort Comfort Includes seats, climate control, noise, and ride
Value Value Did you get what you wanted relative to the price you paid?
Styling Styling How it looks inside and out
Safety Equipment
ABS standard. ESC available from 2009, standard from 2011. Side and head protection air bags available from 2011.
First Drive

General Motors has redesigned its large 2500HD truck line for 2020. (The 2500 references a three-quarter ton payload capacity. This is a historic reference; modern trucks in this class can haul much more than that. The HD is shorthand for heavy-duty.) In any parlance, we can tell you that these GMC and Chevrolet behemoths are bigger and tougher than ever.

GM has supersized these trucks in just about every way, marking the first time the GM HD trucks are truly bigger than their light-duty counterparts.

Seating
3 front, 3 rear
Drive Wheels
4WD , Rear
Warranty
Coverage varies among versions of this vehicle

In most cases, automotive warranties are based on the vehicle identification number (VIN), and the warranty will be valid regardless of ownership. The dealership can tell you exactly how much warranty is left.

Read more about extended warranties
Body Styles
extended cab
regular cab
crew cab
Transmissions Available
  • 10-speed Automatic
  • 6-speed Automatic
Engines Available
  • 6.6-liter V8 (401 hp)
  • 6.6-liter V8 turbodiesel (445 hp)

Owner Reported Trouble Spots

The Reliability score is based on our latest subscriber survey of 2020 GMC Sierra 2500HD owners. The owner comments describe problems respondents experienced with this vehicle.

In-car Electronics

CD or DVD players, radio, speakers, GPS, communication system (e.g., OnStar), display screen freezes or goes blank, phone pairing (e.g. Bluetooth), voice control commands, steering wheel controls, portable music device interface (e.g., iPod/MP3 player), backup or other camera/sensors.

What Owners Say

External music device interface (e.g., smart phone, MP3 player)

"fails to connect to Sirius Satellite and won't pair with my phone. Happened 3 times but the next time I use the vehicle it works."

Anonymous, PA (2020 GMC Sierra 2500HD Denali 6.6-L V8 diesel)
Phone pairing (e.g., Bluetooth)

"seems to be connected to satellite radio issue as they occur at the same time"

Anonymous, PA (2020 GMC Sierra 2500HD Denali 6.6-L V8 diesel)
Radio

"The Sirius XM portion of the tuner often is searching for the satellite and sometimes does not work at all. The vehicle has to be shut off for several minutes to reset."

Anonymous, (2020 GMC Sierra 2500HD SLE 6.6-L V8)

Electric System

Alternator, starter, hybrid battery and related systems, regular battery, battery cables, engine harness, coil, ignition switch, electronic ignition, distributor or rotor failure, spark plugs and wires failure.

What Owners Say

Body control module

"Trailer lights wouldn't work had to get a resistor to make the lights work"

Anonymous, OH (2020 GMC Sierra 2500HD Denali 6.6-L V8 diesel)

Power Equipment

Cruise control, clock, warning lights, body control module, keyless entry, wiper motor or washer, tire pressure monitor, interior or exterior lights, horn, gauges, 12V power plug, remote engine start, alarm or security system

Climate System

Blower (fan) motor, A/C compressor, condenser, evaporator, heater system, automatic climate control, refrigerant leakage, electrical failure.

Engine Minor

Accessory belts and pulleys, engine computer, engine mounts, engine knock or ping, oil leaks.

Engine Major

Engine rebuild or replacement, cylinder head, head gasket, turbo or supercharger, timing chain or timing belt.

Transmission Minor

Gear selector or linkage, leaks, transmission computer, transmission sensor or solenoid, clutch adjustment, rough shifting, slipping transmission.

Drive System

Driveshaft or axle, CV joint, differential, transfer case, 4WD/AWD components, driveline vibration, traction control, electronic stability control (ESC), electrical failure.

Suspension

Shocks or struts, ball joints, tie rods, wheel bearings, alignment, steering linkage (includes rack and pinion), power steering (pumps and hoses, leaks), wheel balance, springs or torsion bars, bushings, electronic or air suspension.

Paint/Trim

Paint (fading, chalking, cracking, or peeling), loose interior and exterior trim or moldings, rust.

Exhaust

Muffler, pipes, catalytic converter, exhaust manifold, leaks.

Body Integrity

Squeaks, rattles, wind noises, loose or cracked seals and/or weather-stripping, air and water leaks.

Brakes

Antilock system (ABS), parking brake, master cylinder, calipers, rotors, pulsation or vibration, squeaking, brake failure or wear.

Engine Cooling

Radiator, cooling fan, antifreeze leaks, water pump, thermostat, overheating.

Body Hardware

Power or manual windows, locks and latches, tailgate, hatch or trunk, doors or sliding doors, mirrors, seat controls, safety belts, sunroof, convertible top.

Fuel System

Check engine light, sensors (includes O2 or oxygen sensor), emission control devices (includes EGR), engine computer, engine computer, fuel cap, fuel gauge/sender, fuel injection system, fuel pump, fuel leaks, stalling or hesitation.

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