2026 GMC Sierra: Sierra 4WD AT4X with Sport Mode · 3.0L · 4WD · 10-speed automatic · Diesel
One configuration of the 2026 GMC Sierra as listed by our sources.
Configuration specifications| Engine | 3.0L 6-cylinder turbocharged |
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| Displacement | 3.0 L |
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| Cylinders | 6 |
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| Fuel type | Diesel |
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| Transmission | 10-speed automatic |
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| Drivetrain | 4WD |
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| Combined economy | 19 mpg (12.4 L/100 km) |
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| City economy | 19 mpg (12.4 L/100 km) |
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| Highway economy | 20 mpg (11.8 L/100 km) |
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