This 2021 GMC Sierra 2500HD AT4 Crew Cab 4WD delivers heavy-duty capability with premium refinement, powered by the legendary Duramax 6.6L Turbo-Diesel V8 paired with an Allison 10-speed automatic transmission for exceptional towing performance and smooth power delivery. Finished in Summit White with a bold AT4 stance, this truck is built to handle demanding work while offering upscale comfort.
Inside, the cabin features Jet Black interior with Kalahari accents, heated and ventilated front seats, a heated steering wheel, and dual-zone automatic climate control to keep you comfortable in any condition. The 10-way power front seats with driver memory and premium materials throughout elevate every drive.
Technology is front and center with an 8" GMC Infotainment System featuring navigation, Apple CarPlay and Android Auto capability, Bluetooth audio streaming, and a Bose premium sound system. Convenience features like remote start, keyless open and start, wireless charging, and a universal home remote make daily use effortless.
Designed for both work and adventure, this Sierra is equipped with Z71 Off-Road suspension, Rancho shocks, skid plates, and an auto-locking rear differential, along with a bed view camera, spray-on bedliner, and LED cargo lighting. The MultiPro tailgate adds unmatched versatility for loading and access.
Safety features include forward collision alert, automatic emergency braking, lane departure warning, front and rear park assist, rear cross traffic alert, blind zone alert, and a following distance indicator, providing confidence whether youre towing or commuting.
Riding on 20" machined aluminum wheels with high gloss black accents and equipped with a trailer brake controller and hitch package, this Sierra AT4 is ready for any job or weekend escape.
"Our people make the difference!!" Pellegrino Buick GMC proudly serving Williamstown, Washington Twp, Sicklerville, Turnersville, Blackwood, Deptford, Clayton, Pitman and all the surrounding Southern New Jersey communities. To take your next vehicle for a ride, simply call Bryan Schuler, Used Car Manager. 856-629-0101 Ext. 203 or email BryanS@pellegrinopbg.com.
Used 2021 GMCSierra 2500HD AT4
- Diesel
- Exterior Color
- Summit White
- Interior Color
- Jet Black With Kalahari Accents
- Odometer
- 167,393 miles
- Body/Seating
- Truck/5 seats
- Transmission
- 10-Speed Automatic
- Drivetrain
- 4WD
- Engine
- Duramax 6.6L V8 Turbodiesel
- VIN
- 1GT49PEY4MF137668
- Stock Number
- 37668
Highlighted Features
- Leather upholstery
- Automatic temperature control
- Premium audio system
- Wireless phone connectivity
- Front dual zone A/C
- Auto-dimming rearview mirror
- Split folding rear seat
- Memory seat
- Heated front seats
- Ventilated front seats
- Perimeter/approach lights
- Remote keyless entry
Included Packages & Accessories
- Heavy Duty Front Spring/Camper Package
- Hitch Package (LPO)
- 6 Speakers
- AM/FM radio: SiriusXM with 360L
- Premium audio system: Premium GMC Infotainment System
- Air Conditioning
- Automatic temperature control
- Front dual zone A/C
- Rear window defroster
- Memory seat
- Power driver seat
- Power steering
- Power windows
- Remote keyless entry
- Steering wheel mounted audio controls
- Speed-sensing steering
- Traction control
- 4-Wheel Disc Brakes
- ABS brakes
- Dual front impact airbags
- Dual front side impact airbags
- Front anti-roll bar
- Front wheel independent suspension
- Low tire pressure warning
- Occupant sensing airbag
- Overhead airbag
- Pickup Box
- Brake assist
- Electronic Stability Control
- Lane Departure Warning System
- Delay-off headlights
- Front fog lights
- Fully automatic headlights
- Panic alarm
- Security system
- Speed control
- 220 Amps Alternator
- Engine Block Heater
- Exhaust Brake
- Heavy-Duty 80 Amp Battery
- High Idle Switch
- AT4 High Clearance Step (LPO)
- Auto-dimming door mirrors
- Bumpers: body-color
- Heated door mirrors
- Power door mirrors
- Rear step bumper
- Turn signal indicator mirrors
- Winter Grille Cover
- 2 USB Ports (1st Row)
- Apple CarPlay/Android Auto
- Auto-dimming Rear-View mirror
- Compass
- Driver door bin
- Driver vanity mirror
- Front reading lights
- Heated steering wheel
- Illuminated entry
- Outside temperature display
- Overhead console
- Passenger vanity mirror
- Rear reading lights
- Rear seat center armrest
- Tachometer
- Telescoping steering wheel
- Tilt steering wheel
- Trip computer
- Voltmeter
- Front Center Armrest
- Heated front seats
- Heated rear seats
- Perforated Leather-Appointed Front Seat Trim
- Power passenger seat
- Split folding rear seat
- Ventilated front seats
- Passenger door bin
- Hitch Guidance w/Hitch View
- In-Vehicle Trailering System App
- Trailer Tire Pressure Monitor Sensors
- 18" Machined Aluminum Wheels
- 20" Machined Aluminum Wheels
- Alloy wheels
- Variably intermittent wipers
- AT4 Preferred Package
- AT4 Premium Plus Package
- Driver Alert Package I
- Driver Alert Package II
- Gooseneck/5th Wheel Package
- Gooseneck/5th Wheel Prep Package
- Preferred Equipment Group 4SB
- Technology Package
- X31 Off-Road Package
- 6-Speaker Audio System Feature
- Bose Premium 7 Speaker Sound System
- HD Radio
- Radio: AM/FM w/Premium GMC Infotainment System
- Radio: Premium GMC Infotainment Sys w/Navigation
- SiriusXM w/360L
- Steering Wheel Audio Controls
- Electric Rear-Window Defogger
- 12-Volt Rear Auxiliary Power Outlet
- 120-Volt Bed Mounted Power Outlet
- 120-Volt Instrument Panel Power Outlet
- Driver Memory
- Power Windows w/Driver Express Up/Down
- Remote Vehicle Starter System
- Universal Home Remote
- Manual Tilt-Wheel/Telescoping Steering Column
- Off-Road Suspension
- Electrical Lock Control Steering Column
- Keyless Open & Start
- Power Door Locks
- Power Sunroof
- Hill Descent Control
- Unauthorized Entry Theft-Deterrent System
- 2-Speed Active Transfer Case
- IntelliBeam Automatic High Beam On/Off
- LED Cargo Area Lighting
- LED Smoked Amber Roof Marker Lamps
- Painted Black Surround Grille
- Rear Wheelhouse Liners
- Spray-On Pickup Box Bed Liner w/AT4 Logo
- 2 USB Ports
- 2nd Row Dual USB Charge-Only Ports
- 4.2" Diagonal Color Display Driver Info Center
- 4G LTE Wi-Fi Hotspot Capable
- 8" Multicolor Driver Information Center
- Automatic Emergency Braking
- Bed View Camera w/2 Trailer Camera Provisions
- Compass Located In Instrument Cluster
- Floor-Mounted Center Console
- Following Distance Indicator
- Forward Collision Alert
- Front Prem Floor Liners w/Removable Carpet Insert
- GMC Connected Access Capable
- HD Rear Vision Camera
- HD Surround Vision
- Inside Rearview Auto-Dimming Rear Camera Mirror
- Lane Change Alert w/Side Blind Zone Alert
- Multicolor 15" Diagonal Head-Up Display
- OnStar & GMC Connected Services Capable
- Rear Cross Traffic Alert
- Rear Prem Floor Liners w/Removable Carpet Insert
- Ultrasonic Front & Rear Park Assist
- Wireless Charging
- Wireless Phone Projection
- 10-Way Power Driver Seat Adjuster w/Lumbar
- 10-Way Power Passenger Seat Adjuster w/Lumbar
- Front Bucket Seats
- Heated & Ventilated Front Bucket Seats
- Heated 2nd Row Outboard Seats
- Heated Driver & Front Outboard Passenger Seats
- Safety Alert Seat
- Integrated Trailer Brake Controller
- Deep-Tinted Glass
- Power Front Passenger Windows w/Express Up/Down
- Power Rear Windows w/Express Down
- Power Sliding Rear Window w/Defogger
Detailed Specifications
- 1-touch down
- 1-touch up
- Air conditioning
- Auto-dimming rearview mirror
- Automatic temperature control
- Driver door bin
- Driver vanity mirror
- Front beverage holders
- Front dual zone A/C
- Heated steering wheel
- Illuminated entry
- Memory seat
- Overhead console
- Passenger door bin
- Passenger vanity mirror
- Power windows
- Proximity key: doors and push button start
- Rear beverage holders
- Rear door bins
- Remote engine start: keyfob
- Remote keyless entry
- Speed control
- Telescoping steering wheel
- Tilt steering wheel
- Alloy wheels
- Front anti-roll bar
- Front wheel independent suspension
- Power steering
- Single rear wheels
- Speed-sensing steering
- Tires: all-terrain
- 1st row LCD monitors: 2
- AM/FM radio: SiriusXM with 360L
- Premium audio system: Premium GMC Infotainment System
- Primary LCD size: 8.0"
- Smart device integration: Android Auto/Apple CarPlay
- Steering wheel mounted audio controls
- Wireless phone connectivity: Bluetooth
- Front center armrest
- Front seats: bucket
- Heated front seats
- Heated rear seats
- Leather upholstery
- Max seating capacity: 5
- Power 2-way driver lumbar support
- Power 2-way passenger lumbar support
- Power driver seat
- Power passenger seat
- Rear seat center armrest
- Rear seats: split-bench
- Rear seats Folding position: fold-up cushion
- Seat Upholstery: leather
- Split folding rear seat
- Ventilated front seats
- Cylinder configuration: V-8
- Drive type: four-wheel
- Engine liters: 6.6L
- Engine location: front
- Fuel tank capacity: 36.0gal.
- Hybrid traction battery type: none
- Manual-shift auto
- Mode select transmission
- Rear locking differential
- Standard fuel economy fuel type: gasoline
- Variable valve control
- Ground clearance (min): 257mm (10.1")
- Auto-dimming door mirrors
- Bedliner
- Bumpers: body-color
- Heated door mirrors
- Left rear passenger door: conventional
- Power door mirrors
- Rear cargo: tailgate
- Rear step bumper
- Right rear passenger: conventional
- Skid plates
- Trailer hitch receiver
- Trailer sway control
- Turn signal indicator mirrors
- Exterior body width: 2,079mm (81.8")
- Exterior height: 2,023mm (79.7")
- Exterior length: 6,352mm (250.1")
- Front headroom: 1,093mm (43.0")
- Front hiproom: 1,554mm (61.2")
- Front legroom: 1,131mm (44.5")
- Front shoulder room: 1,677mm (66.0")
- Rear headroom: 1,013mm (39.9")
- Rear hiproom: 1,530mm (60.2")
- Rear legroom: 1,102mm (43.4")
- Rear shoulder room: 1,659mm (65.3")
- Turning radius: 8.0m (26.3')
- Wheelbase: 4,037mm (158.9")
- Appearance: analog
- Compass
- Delay-off headlights
- Front fog lights
- Front reading lights
- Fully automatic headlights
- Low tire pressure warning
- Oil pressure gauge
- Outside temperature display
- Rear reading lights
- Rear window defroster
- Tachometer
- Trip computer
- Variably intermittent wipers
- Voltmeter
- 4 wheel disc brakes
- ABS brakes
- Brake assist
- Dual front impact airbags
- Dual front side impact airbags
- Electronic stability
- Ignition disable
- Occupant sensing airbag
- Overhead airbag
- Panic alarm
- Perimeter/approach lights
- Security system
- Traction control
Standard Features
- AT4 Preferred Package
- Driver Alert Package I
- Driver Alert Package II
- Power Sunroof
- Technology Package
- Bed View Camera w/2 Trailer Camera Provisions
- HD Surround Vision
- Universal Home Remote
- Power Sliding Rear Window w/Defogger
- Radio: Premium GMC Infotainment Sys w/Navigation
- Bose Premium 7 Speaker Sound System
- LED Smoked Amber Roof Marker Lamps
- Wireless Charging
- Inside Rearview Auto-Dimming Rear Camera Mirror
- Multicolor 15" Diagonal Head-Up Display
- 8" Multicolor Driver Information Center
- Ultrasonic Front & Rear Park Assist
- Lane Change Alert w/Side Blind Zone Alert
- Rear Cross Traffic Alert
- Gooseneck/5th Wheel Prep Package
- Bed View Camera w/2 Trailer Camera Provisions
- Forward Collision Alert
- Automatic Emergency Braking
- IntelliBeam Automatic High Beam On/Off
- Following Distance Indicator
- Safety Alert Seat
- 6-Speaker Audio System Feature
- SiriusXM w/360L
- HD Radio
- Radio: AM/FM w/Premium GMC Infotainment System
- Wireless Phone Projection
- Floor-Mounted Center Console
- Compass Located In Instrument Cluster
- 4.2" Diagonal Color Display Driver Info Center
- Electric Rear-Window Defogger
- Power Door Locks
- Remote Vehicle Starter System
- Keyless Open & Start
- Front Prem Floor Liners w/Removable Carpet Insert
- Rear Prem Floor Liners w/Removable Carpet Insert
- OnStar & GMC Connected Services Capable
- 12-Volt Rear Auxiliary Power Outlet
- 120-Volt Instrument Panel Power Outlet
- 120-Volt Bed Mounted Power Outlet
- 2 USB Ports
- 2nd Row Dual USB Charge-Only Ports
- HD Rear Vision Camera
- Spray-On Pickup Box Bed Liner w/AT4 Logo
- Heated Driver & Front Outboard Passenger Seats
- Heated & Ventilated Front Bucket Seats
- Heated 2nd Row Outboard Seats
- Steering Wheel Audio Controls
- Manual Tilt-Wheel/Telescoping Steering Column
- Electrical Lock Control Steering Column
- Unauthorized Entry Theft-Deterrent System
- Deep-Tinted Glass
- Painted Black Surround Grille
- Power Windows w/Driver Express Up/Down
- Power Front Passenger Windows w/Express Up/Down
- Power Rear Windows w/Express Down
- LED Cargo Area Lighting
- Rear Wheelhouse Liners
- X31 Off-Road Package
- Integrated Trailer Brake Controller
- 2-Speed Active Transfer Case
- 4G LTE Wi-Fi Hotspot Capable
- GMC Connected Access Capable
- 10-Way Power Driver Seat Adjuster w/Lumbar
- 10-Way Power Passenger Seat Adjuster w/Lumbar
- Driver Memory
- Off-Road Suspension
- Hill Descent Control
Dealer Notes
KBB.com Consumer Reviews
- 2.0
Transmission trash
By Jason on Monday, April 07, 2025
Bought a 2023 GMC Duramax diesel Sierra SLT had it for two years hit 50,000 miles. The throttlebody broke went in for service. Got it back three weeks at 62,000 miles now my transmission is slipping. I travel back-and-forth from South Carolina to North Carolina for work daughter’s truck would be my forever truck. What a joke Hundred thousand dollar truck junk - 3.0
Infotainment system unreliable!
By Brian C on Friday, June 27, 2025
The servicing dealer has been great, the GM engineers not so much! The truck will without warning have no sound for the radio and the blinkers. GM told the dealership to reprogram then when that didn't work they said replace the amplifier and when that didn't work, they said replace a module, and when that didn't work they said to replace the amplifier again, and when that didn't work they said we know it's a known problem but we don't know how to fix it. All of this with less than 9k miles. The dealer has done everything that GM has asked them to do, but none of it works. It's very frustrating to pay this much for a truck and you can't get the radio to stay working. It also got away from the factory with paint damage and a dent in the hood,( the dent is from the inside out on a double wall). I thought I was upgrading when I went from a F250 Lariat to a Denali, but I may have traded one headache for another. - 5.0
Fantastic truck
By Jjj on Sunday, November 07, 2021
This one of the most solid vehicles that I have ever driven! The 401 hp engine is more than enough power and the transmission is smooth! Highly recommend this truck!