2026 · Full-Size Pickup · Gas / Flex-fuel

2026 GMC Sierra MPG & fuel economy

The 2026 GMC Sierra is a full-size pickup offered in 16 EPA-rated configurations. The most efficient version returns 20 MPG combined (18 city / 21 highway) on regular gasoline. Across the lineup, combined ratings range from 15 to 20 MPG. That's up 1 MPG from the 2025 model. Among 21 full-size pickups rated for 2026, it ranks 17th for lowest fuel cost. At 15,000 miles a year with $3.10/gal regular gas, it costs about $2,325 a year to fuel.

Compare
Combined 20 MPG 18 MPG city · 21 MPG hwy
Driving range — not published for this model
Your fuel cost $2,325 15,000 mi/yr · $15.50 per 100 mi
Class rank, 2026 #17 of 21 Full-Size Pickups by fuel cost

What will it cost you?

Your mileage and prices are saved and used across the site.

Fuel average

The 2026 GMC Sierra's fuel average is 8.5 km/L (11.8 L/100 km), or 20 MPG combined: 7.7 km/L in the city and 8.9 km/L on the highway.

MPGkm/LL/100 km
City187.713.1
Highway218.911.2
Combined208.511.8

How it ranks among 2026 Full-Size Pickups

Full class ranking →
  1. 1Rivian R1T87 MPGe $1,048
  2. 2Tesla Cybertruck79 MPGe $1,158
  3. 3Chevrolet Silverado EV70 MPGe $1,291
  4. 4GMC Sierra EV68 MPGe $1,336
  5. 5Ford F150 Hybrid24 MPG $1,938
  6. 17GMC Sierra20 MPG $2,325
  7. 21Jeep Gladiator19 MPG $2,447
2026 SierraOther full-size pickupsClass median: $2,214/yr

Annual fuel cost at 15,000 miles and default prices; shorter bars cost less.

Sierra MPG across model years

Full history →

16 EPA-rated configurations

ConfigurationTypeCityHwyCombinedRangeYour cost / yr
RWD · 2.7L 4-cyl turbo · 8-speed automatic
Sierra 2WD		 Gas 18 MPG 21 MPG 20 MPG — $2,325
RWD · 2.7L 4-cyl turbo · 8-speed automatic
Sierra 2WD with Sport Mode		 Gas 17 MPG 21 MPG 19 MPG — $2,447
RWD · 5.3L 8-cyl · 10-speed automatic
Sierra 2WD with Sport Mode		 Gas 16 MPG 21 MPG 18 MPG — $2,583
4WD · 2.7L 4-cyl turbo · 8-speed automatic
Sierra 4WD		 Gas 17 MPG 20 MPG 18 MPG — $2,583
RWD · 5.3L 8-cyl · 10-speed automatic
Sierra 2WD		 Gas 16 MPG 20 MPG 17 MPG — $2,735
4WD · 2.7L 4-cyl turbo · 8-speed automatic
Sierra Mud Terrain Tires 4WD		 Gas 16 MPG 17 MPG 17 MPG — $2,735
4WD · 2.7L 4-cyl turbo · 8-speed automatic
Sierra 4WD with Sport Mode		 Gas 17 MPG 18 MPG 17 MPG — $2,735
4WD · 5.3L 8-cyl · 10-speed automatic
Sierra 4WD FFV		 Flex-fuel 15 MPG 19 MPG 17 MPG — $2,735
4WD · 5.3L 8-cyl · 10-speed automatic
Sierra 4WD with Sport Mode		 Gas 15 MPG 19 MPG 17 MPG — $2,735
4WD · 5.3L 8-cyl · 10-speed automatic
Sierra Mud Terrain Tires 4WD (Sport Mode)		 Gas 15 MPG 18 MPG 16 MPG — $2,906
4WD · 5.3L 8-cyl · 10-speed automatic
Sierra Mud Terrain Tires 4WD		 Gas 14 MPG 17 MPG 16 MPG — $2,906
RWD · 5.3L 8-cyl · 10-speed automatic
Sierra Cab Chassis 2WD		 Gas 15 MPG 18 MPG 16 MPG — $2,906
4WD · 5.3L 8-cyl · 10-speed automatic
Sierra Cab Chassis 4WD		 Gas 14 MPG 16 MPG 15 MPG — $3,100
4WD · 6.2L 8-cyl · 10-speed automatic
Sierra 4WD		 Gas 15 MPG 19 MPG 16 MPG — $3,703
4WD · 6.2L 8-cyl · 10-speed automatic
Sierra Mud Terrain Tires 4WD		 Gas 14 MPG 17 MPG 15 MPG — $3,950
4WD · 6.2L 8-cyl · 10-speed automatic
Sierra 4WD AT4X		 Gas 14 MPG 16 MPG 15 MPG — $3,950

Specs (most efficient configuration)

Fuel
Regular gasoline
Engine / motor
2.7L 4-cyl turbo
Transmission
8-speed automatic
Drivetrain
RWD
Tailpipe CO₂
464 g/mi
EPA fuel economy score
4/10
EPA greenhouse gas score
4/10

2026 GMC Sierra vs. rivals

vs Chevrolet Silverado 20 MPG · $2,325/yr Same fuel cost vs Toyota Tundra 20 MPG · $2,325/yr Same fuel cost vs Chevrolet Silverado Diesel 25 MPG · $2,220/yr Silverado Diesel saves $105/yr vs Ford F150 21 MPG · $2,214/yr F150 saves $111/yr vs Nissan Frontier 21 MPG · $2,214/yr Frontier saves $111/yr vs Chevrolet Colorado 21 MPG · $2,214/yr Colorado saves $111/yr vs Jeep Gladiator 19 MPG · $2,447/yr Sierra saves $122/yr vs GMC Sierra Diesel 25 MPG · $2,220/yr Sierra Diesel saves $105/yr vs GMC Sierra EV 68 MPGe · $1,336/yr Sierra EV saves $988/yr

Compare the 2026 Sierra

With any other car from any year, including other Sierra model years. Type a year to jump, e.g. "2015 Accord".

Same year, other powertrains: 2026 GMC Sierra Diesel (25 MPG), 2026 GMC Sierra EV (68 MPGe)

Frequently asked questions

What is the gas mileage of the 2026 GMC Sierra?

Up to 20 MPG combined (18 city / 21 highway); ratings range from 15 to 20 MPG depending on configuration.

What fuel does the 2026 GMC Sierra use?

Regular gasoline.

What is the fuel average in km/L for the 2026 GMC Sierra?

The 2026 GMC Sierra's fuel average is 8.5 km/L (11.8 L/100 km), or 20 MPG combined: 7.7 km/L in the city and 8.9 km/L on the highway.

How much does it cost to fuel the 2026 GMC Sierra per year?

About $2,325 at 15,000 miles a year with $3.10/gal regular gas, or $15.50 per 100 miles. Use the calculator on this page to plug in your own mileage and prices.

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