2026 GMC Sierra 4WD AT4XFuel Economy & MPG Ratings

Diesel Standard Pickup Trucks 4WD4-Wheel Drive
City
19
MPG
Highway
20
MPG
Combined
19
MPG

Trim Comparison

Automatic 10-spd
Diesel Diesel
City
19
Hwy
20
Comb
19
Fuel cost: $4,450/yr
Automatic 10-spd
Premium
City
14
Hwy
16
Comb
15
Fuel cost: $5,450/yr
Annual Fuel Cost
$4,450

Based on gasoline at $3.67/gal, 15,000 miles/year

5-Year Fuel Savings
$-10,250

vs. average new vehicle

EPA Fuel Economy Score: 4/10
GHG Score: 3/10

Environment

CO₂ Tailpipe Emissions
524 g/mile
Annual Petroleum Consumption
18.8 barrels

Specifications

Engine
6.2L 8-cyl
Transmission
10-speed Automatic
Drivetrain
4WD
Body Style
Pickup Truck
GVWR
Class 2-3 (6,001–10,000 lbs)

Source: EPA fuel economy data & NHTSA vPIC. Specifications reflect the most common trim configuration.

Engine & Efficiency Details

Source: EPA fueleconomy.gov

Engine Size
3L, 6-cylinder
Efficiency Tech
Auto Start-Stop
Fuel Type
Diesel

Annual Fuel Cost by State

Prices as of week ending May 18, 2026 · Source: EIA

National AvgEPA default
$4.490/gal$3,545/yr
California
$5.957/gal$4,703/yr
Texas
$3.888/gal$3,069/yr
Florida
$4.136/gal$3,265/yr
New York
$4.522/gal$3,570/yr
Ohio
$4.510/gal$3,561/yr
Washington
$5.591/gal$4,414/yr
Colorado
$4.618/gal$3,646/yr
Minnesota
$4.344/gal$3,429/yr
Massachusetts
$4.448/gal$3,512/yr

Calculated at 15,000 miles/year (EPA standard assumption) using 19 MPG combined. Regular gasoline prices. Actual costs vary.

Recall History

Source: NHTSA

No recalls reported for this vehicle.

Owner-Reported Problems43 complaints

Source: NHTSA

NHTSA has received 43 owner complaints for the 2026 GMC Sierra 4WD AT4X. Top reported issues include engine, power train and advanced safety (adas). The data below is sourced from consumer complaints filed directly with NHTSA.

Problems by System / Component

Engine
28
Power Train
14
Advanced Safety (ADAS)
6
Electrical System
4
Fuel System
3
Brakes
3
Steering
2
Speed Control
1

2026 GMC Sierra 4WD AT4X problems by category: Engine: 28 complaints, Power Train: 14 complaints, Advanced Safety (ADAS): 6 complaints, Electrical System: 4 complaints, Fuel System: 3 complaints, Brakes: 3 complaints, Steering: 2 complaints, Speed Control: 1 complaints.

Sample Owner Complaints

EngineFiled: 05/12/2026ODI#11737424
On or about 12/14/25 at approximately 2,000 miles my engine began smoking to the point that it was pushing in to the interior of the cabin and created a cloud like atmosphere that smelled of burning o…
Power TrainFiled: 04/20/2026ODI#11732292
I bought the truck brand new from Gregg Young in Atlantic, IA. While an hour into the drive home, the truck began shuttering as if the transmission was having problems finding the gear. I immediately …
EngineFiled: 03/14/2026ODI#11724264
I am the owner of a 2026 GMC Sierra 1500 Denali Ultimate equipped with the 6.2L V8 L87 engine (VIN: [XXX] ), purchased new approximately three months ago. I am filing this complaint proactively. I hav…

Complaint data is sourced from the NHTSA Complaints Database. Reports are filed by vehicle owners and may not reflect confirmed defects. Last updated via NHTSA API.

Related

GMC Sierra 4WD AT4X MPG History
See how this model's fuel economy changed by year

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