Meet this 2021 GMC Sierra 1500 AT4, a capable crew cab short box crafted for both work and adventure. With its 3.0L turbocharged diesel engine, 10-speed automatic transmission, and 4WD capability, this truck delivers impressive fuel economy at an estimated 22 city and 26 highway MPG. The striking white exterior pairs beautifully with a premium jet black leather interior featuring Kalahari accents, creating a refined cabin that doesn't compromise on durability.
Key Features:
- 3.0L I-6 Diesel Turbocharged Engine with Engine Block Heater
- 4WD with Off-Road Suspension and Hill Descent Control
- Premium GMC Infotainment System with Apple CarPlay and Android Auto
- Heated and Ventilated Front Seats with 10-Way Power Adjusters
- HD Rear Vision Camera with Hitch Guidance and In-Vehicle Trailering App
- ProGrade Trailering System with Integrated Trailer Brake Controller
- Remote Vehicle Starter System and Keyless Open & Start
- Goodyear Wrangler DuraTrac Tires on 18 Machined Aluminum Wheels
This AT4 comes well-appointed with modern conveniences including SiriusXM satellite radio, heated steering wheel, power windows and locks, and premium floor liners. The truck sits on LPO sport step and body-color wheel arch moldings, with a spray-on bed liner featuring the AT4 logo. Every detail has been thoughtfully designed for those who demand serious capability.
Stop by to experience this exceptional truck firsthand. We're offering free delivery anywhere in Colorado, and our team is ready to schedule your test drive today.
Proudly serving Longmont, Boulder, Denver, Loveland, Erie, Fort Collins, Thornton, Westminster, Lakewood, Broomfield, Golden, Brighton, and Greeley.
2021 GMC Sierra 1500 AT4
- Used
- Diesel
$895Includes Dealer Handling of:
Mike Maroone Chevrolet Longmont
Call 720-316-0591
We’re here to help
The overview
- Exterior Color
- Summit White
- Interior Color
- Jet Black
- Odometer
- 73,959 miles
- Fuel Economy
- 14/19 MPG City/Hwy
- Transmission
- Automatic
- Drivetrain
- 4x4
- Engine
- I-6 cyl
- VIN
- 1GTU9EET7MZ397814
- Stock Number
- L397814
The full specifications
- 3-point seatbelt : Rear seat center 3-point seatbelt
- ABS Brakes : 4-wheel antilock (ABS) brakes
- Auto headlights : Auto on/off headlight control
- Brake assist system : Brake assist system
- Brake type : 4-wheel disc brakes
- Cab mounted cargo light : Cab mounted cargo light
- Child door locks : Manual rear child safety door locks
- Delay off headlights : Delay-off headlights
- Electronic stability control : StabiliTrak w/Proactive Roll Avoidance electronic stability control system with anti-roll
- Fog lights : LED front fog lights
- Front impact airbag driver : Driver front impact airbag
- Front impact airbag passenger : Passenger front impact airbag
- Front side impact airbag driver : Seat mounted side impact driver airbag
- Front side impact airbag passenger : Seat mounted side impact front passenger airbag
- Headlight type : Reflector headlights
- Headlights : LED low and high beam headlights
- High mount stop light : High mounted center stop light
- Hill control : Hill Descent Control (HDC)
- Hill start assist : Hill Start Assist (HSA)
- Illuminated entry : Illuminated entry
- Immobilizer : Immobilizer
- Instrumentation display : Analog instrumentation display
- LED brake lights : LED brake lights
- Low tire pressure warning : Tire specific low air pressure warning
- Multiple headlights : Multiple enclosed headlights
- Number of airbags : 6 airbags
- Occupancy sensor : Airbag occupancy sensor
- Overhead airbags : Curtain first and second-row overhead airbags
- Perimeter approach lighting : Remote activated perimeter approach lighting
- Rear camera : HD Rear Vision Camera w/Hitch View rear mounted camera
- Remote panic alarm : Remote panic alarm
- Restricted driving mode/alerts : Teen Driver restricted driving mode/alerts
- Running lights : LED daytime running lights
- Seatbelt pretensioners : Front seatbelt pretensioners
- Seatbelt pretensioners number : 2 seatbelt pre-tensioners
- Security system : Security system
- Air conditioning : Yes
- Armrests front center : Front seat center armrest
- Armrests rear : Rear seat center armrest
- Cabback insulator : Cabback insulator
- Climate control : Automatic climate control
- Cooled front seats : Ventilated driver and front passenger seats
- Door panel insert : Simulated wood and metal-look door panel insert
- Door trim insert : Vinyl door trim insert
- Driver lumbar : Driver seat with 2-way power lumbar
- Driver seat direction : Driver seat with 8-way directional controls
- Dual-zone front climate control : Dual-zone front climate control
- Floor coverage : Full floor coverage
- Floor covering : Full carpet floor covering
- Floor mats : Rubber front and rear floor mats with carpet inserts
- Folding rear seats : 60-40 folding rear seats
- Front head restraint control : Manual front seat head restraint control
- Front head restraints : Height adjustable front seat head restraints
- Front passenger lumbar : Front passenger seat with 2-way power lumbar
- Front seat upholstery : Leather front seat upholstery
- Front seatback upholstery : Plastic front seatback upholstery
- Gearshifter material : Urethane gear shifter material
- Headliner coverage : Full headliner coverage
- Headliner material : Cloth headliner material
- Heated front seats : Heated driver and front passenger seats
- Heated rear seats : Heated rear seats
- Heated steering wheel : Heated steering wheel
- Interior accents : Chrome interior accents
- Number of memory settings : 2 memory settings
- Panel insert : Metal-look instrument panel insert
- Passenger seat direction : Front passenger seat with 8-way directional controls
- Power driver seat controls : Driver seat power reclining, lumbar support, cushion tilt, fore/aft control and height adjustable control
- Power passenger seat controls : Passenger seat power reclining, lumbar support, cushion tilt, fore/aft control and height adjustable control
- Rear console climate control ducts : Rear console climate control ducts
- Rear head restraint control : 2 rear seat head restraints
- Rear head restraint control : Manual rear seat head restraint control
- Rear head restraints : Height adjustable rear seat head restraints
- Rear seat folding position : Fold-up rear seat cushion
- Rear seat upholstery : Vinyl rear seat upholstery
- Rear seatback upholstery : Carpet rear seatback upholstery
- Rear seats : Split-bench rear seat
- Rear seats fixed or removable : Fixed rear seats
- Seating capacity : 5
- Split front seats : Bucket front seats
- Steering wheel material : Leather steering wheel
- Steering wheel telescopic : Manual telescopic steering wheel
- Steering wheel tilt : Manual tilting steering wheel
- Tinted windows : Deep tinted windows
- 12V power outlets : 2 12V power outlets
- Accessory power : Retained accessory power
- All-in-one key : All-in-one remote fob and ignition key
- Auto door locks : Auto-locking doors
- Auto-dimming door mirror driver : Auto-dimming driver side mirror
- Battery charge warning : Battery charge warning
- Beverage holders : Front beverage holders
- Beverage holders rear : Rear beverage holders
- Brake pad warning : Brake pad wear indicator
- Capless fuel filler : Capless fuel filler
- Clock : Digital clock
- Compass : Compass
- Cruise control : Cruise control with steering wheel mounted controls
- DEF fluid gauge : Diesel exhaust fluid (def) gauge
- Day/Night rearview mirror : Day/Night rearview mirror
- Door ajar warning : Door ajar warning
- Door bins front : Driver and passenger door bins
- Door bins rear : Rear door bins
- Door locks : Power door locks with 2 stage unlocking
- Door mirror with tilt-down in reverse : Power driver and passenger door mirrors with tilt down in reverse
- Driver foot rest : Driver foot rest
- Driver information center : Driver information center
- Easy lift tailgate : EZ Lift
- Easy lower tailgate : EZ Lower
- Engine hour meter : Engine hour meter
- Engine temperature warning : Engine temperature warning
- Engine/electric motor temperature gauge : Engine/electric motor temperature gauge
- Exterior 120V AC power outlet : 1 exterior 120V AC power outlet
- First-row windows : Power first-row windows
- Floor console : Full floor console
- Floor console storage : Covered floor console storage
- Folding door mirrors : Power folding door mirrors
- Front reading lights : Front reading lights
- Glove box : Locking glove box
- Headlights on reminder : Headlights on reminder
- Heated door mirrors : Heated driver and passenger side door mirrors
- Ignition type : Push-button
- Inclinometer : Inclinometer
- Integrated tailgate step : Integrated tailgate step
- Interior 120V AC power outlets : 1 interior 120V AC power outlet
- Key in vehicle warning : Key in vehicle warning
- Keyfob cargo controls : Keyfob trunk control
- Keyfob keyless entry : Keyfob keyless entry
- Keyfob remote start : Keyfob remote start
- Keyfob window controls : Keyfob window control
- Low level warnings : Low level warning for oil, coolant, fuel, washer fluid, brake fluid and diesel exhaust fluid (DEF)
- Memory settings : Memory settings include: door mirrors
- Number of beverage holders : 6 beverage holders
- Oil pressure gauge : Oil pressure gauge
- Oil pressure warning : Oil pressure warning
- One-touch down window : Front and rear one-touch down windows
- One-touch up window : Driver and passenger one-touch up windows
- Overhead console : Mini overhead console
- Overhead console storage : Overhead console storage
- Passenger doors rear left : Conventional left rear passenger door
- Passenger doors rear right : Conventional right rear passenger door
- Proximity key : Proximity key with hands-free access and push button start
- Rear cargo door : MultiPro Tailgate tailgate
- Rear reading lights : Rear reading lights
- Rear seat check warning : Rear seat check warning
- Rear seat direction : Front facing rear seat
- Rear window defroster : Rear window defroster
- Rear windshield : Fixed rear windshield
- Rearview mirror : Auto-dimming rear view mirror
- Seatback storage pockets : 2 seatback storage pockets
- Second-row windows : Power second-row windows
- Service interval warning : Service interval indicator
- Speedometer : Redundant digital speedometer
- Steering mounted audio control : Steering wheel mounted audio controls
- Tachometer : Tachometer
- Tailgate control : Tailgate/power door lock
- Temperature display : Exterior temperature display
- Tire pressure : Tire Fill Alert tire pressure fill assist
- Transmission fluid temperature warning : Transmission fluid temp warning
- Transmission temperature gauge : Transmission fluid temperature gauge
- Trip computer : Trip computer
- Trip odometer : Trip odometer
- Turn signal warning : Turn signal on warning
- Under seat tray rear : Rear under seat tray
- Variable panel light : Variable instrument panel light
- Visor driver mirror : Driver visor mirror
- Visor illuminated driver mirror : Illuminated driver visor mirror
- Visor illuminated passenger mirror : Illuminated passenger visor mirror
- Visor passenger mirror : Passenger visor mirror
- Voltmeter : Voltmeter
- Wipers : Variable intermittent front windshield wipers
- Bed extender : Pickup bed extender
- Bed liner : Spray-in pickup bed liner
- Bed-rail protectors : Pickup bed-rail protectors
- Body panels : Galvanized steel/aluminum body panels with side impact beams
- Box style : Standard style pickup box
- Bumper rub strip front : Black front bumper rub strip
- Bumpers front : Body-colored front bumper
- Bumpers rear : Body-colored rear bumper
- Door handle material : Body-colored door handles
- Door mirror style : Black door mirrors
- Door mirror type : Standard style side mirrors
- Fenders : Body-colored fender flares
- Grille style : Chrome grille with body-color surround
- In-box lighting : LED in-box lighting
- License plate front bracket : Front license plate bracket
- Number of doors : 4 doors
- Paint : Non-metallic paint
- Rear bumper step : CornerStep rear bumper step
- Running boards : Running boards
- Skid plate : 2 underbody skid plates
- Spare tire : Full-size spare tire with steel wheel
- Spare tire location : Crank-down spare tire
- Special paint : Monotone paint
- Tires : LT275/65QR18 MT BSW front and rear tires
- Tow hooks front : 2 front tow hooks
- Towing brake controller : Trailer brake controller
- Towing class : Class IV tow rating
- Towing hitch : Trailer hitch
- Towing hitch light : Trailer hitch light
- Towing trailer sway : Trailer Sway Control (TSC) trailer sway control
- Towing wiring harness : Trailer wiring harness
- Trailer light malfunction warning : GMC ProGrade Trailering System trailer light malfunction warning
- Trailer light test : GMC ProGrade Trailering System trailer light test
- Trailer theft alarm : GMC ProGrade Trailering System trailer theft alarm
- Vehicle and trailer reverse assist : Trailering Assist Guidelines vehicle and trailer reverse assist with visual graphic guidance only
- Vehicle to trailer hitching assist : Hitch Guidance vehicle to trailer hitching assist
- Wheels : 18 x 8.5-inch front and rear machined w/painted accents aluminum wheels
- Window Trim : Black side window trim
- Emissions : Federal emissions
- Emissions tiers : Tier 2 Bin 5 emissions
- Fuel economy (city/highway/combined) : 22/26/24 MPG
- Antenna : Fixed audio antenna
- Aux input jack : Auxiliary input jack
- External memory : Premium GMC Infotainment System external memory control
- Internet radio capability : Internet radio capability
- Number of first-row screens : 2 total number of 1st row displays
- Primary display size : 8 inch primary display
- Primary display touchscreen : Primary monitor touchscreen
- RDS : Radio data system (RDS)
- Radio : AM/FM/SiriusXMsatellite
- Satellite trial : 3 month satellite trial subscription
- Seek scan : Seek scan
- Speakers : Standard grade speakers
- Speakers number : 6 speakers
- Voice activated audio : GMC Infotainment System voice activated audio controls
- Wireless streaming : Bluetooth wireless audio streaming
- 4WD type : AutoTrac part and full-time 4WD
- ABS Brakes : Four channel ABS brakes
- Alternator Type : Alternator
- Battery run down protection : Battery run down protection
- Battery type : Heavy-duty lead acid battery
- Block heater : Engine block heater
- Compressor : Intercooled turbo
- Cylinder head material : Aluminum cylinder head
- Displacement liters : 3 L
- Drive type : Four-wheel drive
- Electronic parking brake : Electronic parking brake
- Engine : Duramax 3L I-6 direct injection, DOHC, variable valve control, intercooled turbo, diesel, engine with 277HP
- Engine Configuration : I6
- Engine Location : Front mounted engine
- Engine Mounting direction : Longitudinal mounted engine
- Engine Short : Duramax 3L I-6 DOHC
- Engine block material : Aluminum engine block
- Front anti-roll : Front anti-roll bar
- Fuel Type : Diesel
- Horsepower : 277 HP @3750 RPM
- Ignition : Compression ignition system
- Lock-up transmission : Lock-up transmission
- Locking hub control : Auto locking hub control
- Overdrive transmission : Overdrive transmission
- Powertrain type : ICE
- Radiator : Radiator
- Rear Springs : Regular grade rear springs
- Rear locking differential : Automatic rear locking differential
- Selectable mode transmission : Tow/Haul Mode selectable mode transmission
- Sequential shift control : Sequential shift control
- Shock absorbers : Rancho shock absorbers
- Speed sensitive steering : Speed sensitive power steering
- Springs front : Front coil springs
- Springs rear : Rear leaf springs
- Start-stop engine : Auto stop-start engine
- Steering : Electric power-assist steering system
- Steering type : Rack-pinion steering
- Suspension : Off-road ride suspension
- Suspension ride type front : Independent front suspension
- Suspension ride type rear : Rigid axle rear suspension
- Suspension type front : Short and long arm front suspension
- Suspension type rear : Leaf spring rear suspension
- Tailpipe : Stainless steel dual exhaust with polished tailpipe finisher
- Traction control : All-speed ABS and driveline traction control
- Transfer case : Electronic transfer case shift
- Transmission : 10-speed automatic
- Transmission Type : Automatic
- Valves per cylinder : 4
- Variable intake manifold : Variable intake manifold
- Ventilated brakes : Front and rear ventilated disc brakes
- Handsfree : Bluetooth handsfree wireless device connectivity
- Internet access : 4G LTE Wi-Fi Hotspot capable mobile hotspot internet access
- Smart device integration : Apple CarPlay/Android Auto smart device mirroring
- USB ports : 6 USB ports
Notes from the dealer
Peace of mind
Vehicle history report
- Title information
- Odometer readings
- Accident data (if applicable)
- Service history
- Vehicle usage
- Recall information (if applicable)
- Warranty status
A name you can trust
Mike Maroone Chevrolet South is dedicated to your satisfaction before, during, and after your purchase. We'll go the extra mile to take care of you.
More about usKBB.com Consumer Reviews
4.0out of 5 overall- 4.0
Depreciation of 50%
by Manny A on 10/28/2026 10:06:36 AM
This is a amazing truck.. Comfortable lots of sensors Etc…. My truck has 30000 miles I when to trade in they offer $46000 I paid $86000 the depreciation is incredible I don’t buy new truck never again. - 5.0
2021 GMC SLT 4WD SIERRA, Great Truck
by Ransom1 on 10/15/2026 4:18:42 PM
This is my 8th truck. This is hands down the very best truck I’ve ever owned. Not only is it the best looking truck on the road I have never had it in the shop except for oil changes and scheduled maintenance. The silver does not show dirt or grime. - 5.0
Great 4 cylinder truck
by Steve on 9/23/2026 2:01:15 AM
I have only pulled a trailer one time and still got 18 mpg down doing 80 down the interstate. Otherwise this vehicle is used for commuting or recreating. I typically get 22-24 mpg driving MT highways to the mountains. The turbo has some spunk for getting up to speed and the five years I've had my truck no complaints.
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