This page collects every fuel-economy figure the EPA publishes for the 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode). Below you will find the headline combined, city, and highway MPG, the estimated annual fuel cost at three different driving levels, the tailpipe CO₂ emissions, and a full breakdown of the engine and drivetrain.

Key takeaways

  • Returns 62% worse combined MPG than the average car in the Standard Pickup Trucks 4WD class for the 2026 model year (41.6 MPG class average).
  • The most efficient car in the Standard Pickup Trucks 4WD class for the 2026 model year is the Rivian R1T Dual Max (22in) at 87 MPG.
  • EPA estimates this car costs around $8,000 more in fuel over five years than an average new vehicle of the same model year.

Fuel economy at a glance

These are the EPA's official ratings for the 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode). The numbers come from a standardised laboratory test cycle and are the same figures that appear on the window sticker of every new car. Real-world mileage varies with driving style, weather, fuel quality, and how heavily loaded the car is.

Combined MPG is a 55/45 weighted blend of the city and highway test cycles. The EPA uses it as the single number you can compare across the entire dataset, including hybrids and EVs (which use the equivalent MPGe figure).

Combined MPG 16 MPG
City MPG 15 MPG
Highway MPG 18 MPG
Annual fuel cost $3,750
Tailpipe CO₂ 561 g/mi
Fuel type Regular

How the 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode) compares

The 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode) returns 16 combined MPG. Cars in the Standard Pickup Trucks 4WD class for the same model year average 41.6 MPG, which puts this car behind the class average by about 62%.

The most efficient car in the Standard Pickup Trucks 4WD class for the 2026 model year is the Rivian R1T Dual Max (22in) at 87 MPG. The bar chart below puts the GMC Sierra Mud Terrain Tires 4WD (Sport Mode) alongside the class best and the class average so you can see the full picture.

For broader context, the average new car of the 2026 model year (across all classes) returns 45.5 MPG. Larger vehicles pull the all-cars average down, so do not use that figure on its own to judge a small car or a hybrid. The full list of the most efficient cars of the 2026 model year is on its own page.

2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode)
16 MPG
Class average, 2026
41.6 MPG
Class best, 2026
87 MPG
Average new car, 2026
45.5 MPG

Annual fuel cost across driving patterns

The headline annual fuel cost the EPA publishes assumes 15,000 miles of driving per year and a fuel mix of 55% city and 45% highway. The dollar figure is calculated using the EPA's current reference price for regular gasoline, which is $3.99/gallon. EPA updates that reference periodically rather than tracking live pump prices, so treat it as a window-sticker estimate rather than today's pump number.

The table below scales the EPA's number to three common driving patterns. The combined MPG and the reference fuel price stay constant, only the annual mileage changes. To get a current-prices estimate, take your local gas price and multiply by 937.5 gallons (the car's annual consumption at the rated MPG).

Driving pattern Estimated annual fuel cost
Light driver, 7,500 miles per year $1,875
Average driver, 15,000 miles per year $3,750
Heavy driver, 25,000 miles per year $6,250

Compare against other Standard Pickup Trucks 4WD for 2026

If you are cross-shopping the 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode), the most useful comparison is against the other cars in the Standard Pickup Trucks 4WD class for the same model year. The list below shows the highest-MPG peers, ranked from most to least efficient. Click any of them to open its full page.

The Rivian R1T Dual Max (22in) leads this group at 87 MPG, 71 MPG ahead of the 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode).

Specifications

The 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode) runs a 5.3-liter 8-cylinder engine paired with a automatic 10-spd, sending power through 4-wheel drive.

Engine, transmission, and drivetrain together drive most of the variation in fuel economy across trims. A larger engine moves the car with less effort but burns more fuel. A turbo lets a small engine punch above its weight, often without much MPG penalty. All-wheel drive adds traction and weight, and usually costs a couple of MPG compared with two-wheel drive of the same engine.

Vehicle class
Standard Pickup Trucks 4WD
Engine
5.3L 8-cylinder
Transmission
Automatic 10-spd
Drivetrain
4-Wheel Drive
Fuel type
Regular
Annual petroleum use
18.6 barrels per year
Start-stop system
Yes

Common questions about the 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode)

Quick answers to the questions people most often search for when looking up the 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode).

  • Is the 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode) fuel efficient?
    Not particularly. The 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode) returns 16 combined MPG, which trails the average car in the Standard Pickup Trucks 4WD class for the same model year by about 62%.
  • What MPG does the 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode) get?
    The EPA rates the 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode) at 16 combined MPG, 15 MPG in city driving, and 18 MPG on the highway. Real-world numbers depend on your driving style, the weather, and how loaded the car is.
  • How much does it cost to fuel a 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode) per year?
    The EPA estimates an annual fuel cost of $3,750 for the 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode). That figure assumes 15,000 miles of driving per year, a 55% city and 45% highway split, and the EPA's published average fuel price for the rated fuel grade.
  • What fuel does the 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode) use?
    The EPA lists the 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode) as running on regular gasoline. Using a different grade than the manufacturer specifies can affect fuel economy and engine longevity.
  • How much CO₂ does the 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode) emit?
    Tailpipe CO₂ emissions are 561 g/mi. Multiplied across a typical year of driving (15,000 miles) that works out to about 8,415 kilograms of CO₂.
  • What is the difference between the city and highway MPG of the 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode)?
    City driving returns 15 MPG and highway driving returns 18 MPG, a gap of 3 MPG. The two figures are close enough that the car will hold its rated efficiency well across most driving patterns.
  • What engine is in the 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode)?
    The 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode) has a 5.3-liter 8-cylinder engine (EPA description: SIDI).
  • What transmission and drivetrain does the 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode) have?
    The 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode) comes with a automatic 10-spd transmission and 4-wheel drive.
  • How does the 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode) compare to the best car in its class?
    The most efficient car in the Standard Pickup Trucks 4WD class for the 2026 model year is the Rivian R1T Dual Max (22in) at 87 combined MPG. The GMC Sierra Mud Terrain Tires 4WD (Sport Mode) returns 16 MPG, a gap of 71 MPG. If you are comparing on fuel economy alone, the class leader is worth a look.
  • How much more does the 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode) cost in fuel compared to an average car?
    The EPA estimates that over five years, the 2026 GMC Sierra Mud Terrain Tires 4WD (Sport Mode) will cost about $8,000 more in fuel than an average new vehicle of the same model year. The difference accumulates because the car uses more fuel per mile, not because of any one-off charge at the dealership.

Source: U.S. EPA fuel economy dataset. Annual fuel cost figures assume 15,000 miles of driving per year and a 55% city, 45% highway split. Real-world mileage varies with driving conditions, vehicle maintenance, fuel quality, and driver behaviour.