2012 GMC Sierra C15

Truck Flex Fuel
GMC Sierra C15 2012
17MPG Combined
4 Trims
← 2011 2012 2013 →
Updated February 27, 2026

The 2012 GMC Sierra C15 Truck provides 14–17 combined MPG depending on trim. We’ve compiled EPA fuel economy data, NHTSA safety ratings, and recall history so you can make an informed decision.

2012 GMC Sierra C15 Specifications

SpecValue
Combined MPG14–17 combined MPG depending on trim
City MPG15
Highway MPG21
Body StyleTruck
Fuel TypeFlex Fuel
DriveRWD
Available Trims4

Available Trims

TrimMPG (City/Hwy/Combined)EngineTransmission
Auto15/21/175.3L 8cylAutomatic 6-spd
Auto13/18/146.2L 8cylAutomatic 6-spd
Auto15/20/174.3L 6cylAutomatic 4-spd
Auto14/19/164.8L 8cylAutomatic 4-spd

Annual Fuel Cost

Based on EPA estimates, the 2012 GMC Sierra C15 costs approximately $2,775 per year in fuel. This assumes 15,000 miles driven annually and current fuel prices.

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