Classic Buick GMC / Houston

Used

2021 GMC Sierra 1500 AT4

AT4 · 4WD · STOCK TMG344589 · HOUSTON, TX

Advertised price$31,342

Includes $225 doc fee. Excludes tax, title and license.

Est. $565/mo · 72 months · 8.99% APR · $0 down. On approved credit; before tax and licensing.

Odometer: 134,168 mi
Drivetrain: 4WD
Engine: EcoTec3 5.3L V8
Fuel economy: 16 / 21 MPG

In stock

Ask about this vehicle Call (281) 579-4300

Updated November 11, 2026

This 2021 GMC Sierra 1500 AT4 is in stock at Classic Buick GMC in Houston, TX. It shows 134,168 mi on the odometer, is finished in Cayenne Red Tintcoat, is 4WD, and advertised at $31,342.

About this vehicle

No-Haggle, Transparent Pricing: We are a One-Price dealership—the price you see online is our absolute best price, with zero negotiation. Buy with confidence! This 2021 GMC Sierra 1500 AT4 Crew Cab presents a commanding presence in striking Cayenne Red, powered by a potent EcoTec3 5.3L V8 engine with a 10-speed automatic transmission and 4WD capability. The jet black leather interior with Kalahari accents creates a refined cabin that balances rugged durability with premium comfort. With 134,168 miles reflecting steady highway use, this truck delivers the proven reliability and capability AT4 trucks are built for, now priced to move.- Power sunroof with large glass panel- Heated and ventilated front leather seats with 10-way power adjusters- GMC Infotainment System with navigation and 8-inch touchscreen display- Apple CarPlay and Android Auto smartphone integration- HD surround vision cameras with trailer view provisions- Lane Keep Assist, Lane Change Alert, and Forward Collision Alert- All-weather floor liners and spray-on bed liner with AT4 logo- 20-inch machined aluminum wheels with all-terrain tires- Adaptive Cruise Control with following distance indicator- Wireless charging and dual USB charging portsThis AT4 combines advanced safety technology with genuine off-road credentials. The Driver Alert Package II, Hill Descent Control, and proactive braking systems work together to keep you confident in any condition. The truck's professional-grade features—from the integrated trailer brake controller to the ProGrade Trailering System—make it equally at home on the job or on weekend adventures.We invite you to experience this capable Sierra in person and discover why the AT4 remains a top choice for buyers seeking serious truck capability with refined comfort and the latest technology.

Estimate your payment

$565/ month (est.)$31,342 financed

Vehicle price$31,342

Down payment$0

Trade-in value$0

Loan term

Terms over 72 months are not typically written at this vehicle’s age and mileage.

Credit

Pick a band for a typical rate — nothing is checked, nothing is pulled.

Or set the rate yourself (APR)8.99%

Band rates are Classic Buick GMC's configured lender rates. Estimate only, on approved credit; not a financing offer. Taxes, title, registration, and fees are not included. Actual rate and payment will vary.

Buying guides for this vehicle

Specifications

Powertrain & efficiency

Engine: EcoTec3 5.3L V8
Transmission: 10-Speed Automatic
Drivetrain: 4WD
Fuel: Gasoline
Fuel economy: 16 / 21 MPG

Body & dimensions

Body: 4D Crew Cab
Doors: 4
Exterior: Cayenne Red Tintcoat
Interior: Jet Black With Kalahari Accents

Identification

Year: 2021
Make: GMC
Model: Sierra 1500
Trim: AT4
VIN: 3GTP9EED6MG344589
Stock: TMG344589
Condition: Used

Features

01AT4 Preferred Package
02AT4 Value Package
03Driver Alert Package I
04Driver Alert Package II
05Preferred Equipment Group 4SB
06Technology Package
07Trailering Package
086 Speakers
096-Speaker Audio System Feature
10AM/FM radio: SiriusXM with 360L
11Premium audio system: GMC Infotainment System
12Premium Bose 7-Speaker Sound System
13Radio data system
14Radio: Premium GMC Infotainment Sys w/Multi-Touch
15Radio: Premium GMC Infotainment Sys w/Navigation
16SiriusXM w/360L
17Steering Wheel Audio Controls
18Air Conditioning
19Automatic temperature control
20Electric Rear-Window Defogger
21Front dual zone A/C
22Rear window defroster
2312-Volt Rear Auxiliary Power Outlet
24120-Volt Bed Mounted Power Outlet
25120-Volt Instrument Panel Power Outlet
26Driver Memory
27Memory seat
28Power driver seat
29Power Front Passenger Windows w/Express Up/Down
30Power Front Windows w/Driver Express Up/Down
31Power Rear Windows w/Express Down
32Power steering
33Power windows
34Remote keyless entry
35Remote Vehicle Starter System
36Steering wheel mounted audio controls
37Universal Home Remote
38Auto-Locking Rear Differential
39Electrical Lock Control Steering Column
40Manual Tilt-Wheel & Telescoping Steering Column
41Off-Road Suspension
42Speed-sensing steering
43Traction control
444-Wheel Disc Brakes
45ABS brakes
46Dual front impact airbags
47Dual front side impact airbags
48Front anti-roll bar
49Front wheel independent suspension
50Keyless Open & Start
51Low tire pressure warning
52Occupant sensing airbag
53Overhead airbag
54Power Door Locks
55Power Sunroof
56Brake assist
57Electronic Stability Control
58Hill Descent Control
59Delay-off headlights
60Front fog lights
61Fully automatic headlights
62Perimeter Lighting
63Panic alarm
64Security system
65Theft Deterrent System (Unauthorized Entry)
66Adaptive Cruise Control
67Speed control
68170 Amp Alternator
69Auxiliary External Transmission Oil Cooler
70Heavy-Duty Air Filter
71Auto-dimming door mirrors
72Body-Color Surround Grille
73Bumpers: body-color
74Front License Plate Kit
75Heated door mirrors
76IntelliBeam Automatic High Beam On/Off
77LED Cargo Area Lighting
78Power door mirrors
79ProGrade Trailering System
80Rear step bumper
81Rear Wheelhouse Liners
82Spray-On Pickup Bed Liner w/AT4 Logo
832 USB Ports
842 USB Ports (1st Row)
854.2" Diagonal Color Display Driver Info Center
864G LTE Wi-Fi Hotspot Capable
878" Driver Information Center
88All-Weather Floor Liners w/AT4 Logo (LPO)
89Apple CarPlay/Android Auto
90Auto-dimming Rear-View mirror
91Automatic Emergency Braking
92Bed View Camera
93Color-Keyed Carpeting Floor Covering
94Compass
95Driver door bin
96Driver vanity mirror
97Floor-Mounted Center Console
98Following Distance Indicator
99Forward Collision Alert
100Front Pedestrian Braking
101Front Prem Floor Liners w/Removable Carpet Insert
102Front reading lights
103GMC Connected Access Capable
104HD Rear Vision Camera
105HD Surround Vision w/2 Trailer View Camera Provisions
106Heated steering wheel
107Illuminated entry
108Lane Change Alert w/Side Blind Zone Alert
109Lane Keep Assist w/Lane Departure Warning
110Multicolor 15" Diagonal Head-Up Display
111OnStar & GMC Connected Services Capable
112Outside temperature display
113Overhead console
114Passenger vanity mirror
115Rear Camera Mirror
116Rear Cross Traffic Alert
117Rear Dual USB Charging-Only Ports
118Rear Prem Floor Liners w/Removable Carpet Insert
119Rear reading lights
120Rear seat center armrest
121Safety Alert Seat
122Tachometer
123Telescoping steering wheel
124Tilt steering wheel
125Trip computer
126Ultrasonic Front & Rear Park Assist
127Voltmeter
128Wireless Charging
12910-Way Power Driver Seat Adjuster w/Lumbar
13010-Way Power Passenger Seat Adjuster w/Lumbar
131Front Bucket Seats
132Front Center Armrest
133Heated 2nd Row Outboard Seats
134Heated Driver & Front Outboard Passenger Seating
135Heated front seats
136Perforated Leather-Appointed Front Seat Trim
137Power passenger seat
138Split folding rear seat
139Ventilated Driver & Front Passenger Seats
140Ventilated front seats
141Passenger door bin
142Hitch Guidance
143Hitch Guidance w/Hitch View
144In-Vehicle Trailering App
145Integrated Trailer Brake Controller
146Red Recovery Hooks
14718" x 8.5" Machined Aluminum Wheels
148Alloy wheels
149Wheel Locks (Set of 4) (LPO)
150Wheels: 20" x 9" Machined Aluminum
151Deep-Tinted Glass
152Power Sliding Rear Window w/Rear Defogger
153Variably intermittent wipers
1543.23 Rear Axle Ratio

Location & availability

In stock at Classic Buick GMC, Houston, TX.

The record

The details behind this vehicle.

This is the decoded record for this exact vehicle — not the model, not the trim, this serial number. Every figure below is computed from it or from vehicles physically on this lot.

VIN 3GTP9EED6MG344589CHECK DIGIT VALID

3GT

POS 1–3

World manufacturer

Assigned to GMC

P9EED

POS 4–8

Vehicle attributes

Decodes to EcoTec3 5.3L V8 · 4D Crew Cab · 4WD

POS 9

Check digit

Validates the other sixteen

POS 10

Model year

2021

POS 11

Assembly plant

344589

POS 12–17

Serial number

This unit, and only this unit

SOURCE: VIN DECODE RECORDTHE SAME RECORD AI AGENTS READ

Where it sits on this lot

$31,342

$7,937$80,874

In the lower half of this lot by price.

Miles per year

22,361

134,168 mi across 6 model years.

Estimated payment by credit band

Excellent$549/mo · 7.99% · 72 mo

Good$565/mo · 8.99% · 72 mo

Fair$629/mo · 12.99% · 72 mo

Rebuilding$593/mo · 16.99% · 72 mo

With 0% down. Estimates only, on approved credit; not a financing offer.

Every figure here is computed from data tied to this VIN or to vehicles on this lot. Nothing is a market estimate we can’t show the inputs for.

$31,342Enquire

2024 Chevrolet Colorado LT

$36,124

est. $581/mo

21,841 mi8-Speed Automatic4WD

VIN1GCPTCEK2R1304116

34 photos

2024 Chevrolet Tahoe LT

$38,970

est. $627/mo

76,465 mi10-Speed Automatic with OverdriveRWD

VIN1GNSCNKD3RR274600

33 photos

2025 Honda Pilot Elite

$46,037

Elite

est. $740/mo

25,872 mi10-Speed AutomaticAWD

VIN5FNYG1H85SB100579

32 photos

2026 Ram 1500 Big Horn/Lone Star

$39,034

Big Horn/Lone Star

est. $628/mo

25,315 mi8-Speed Automatic4WD

VIN1C6SRFFP6TN249200