2015 GMC Sierra K15

Truck Flex Fuel
GMC Sierra K15 2015
19MPG Combined
4 Trims
← 2014 2015 2016 →
Updated February 27, 2026

Get the full picture on the 2015 GMC Sierra K15. As a Truck, it achieves 17–19 combined MPG depending on trim and has not yet been rated by NHTSA. Below you’ll find detailed specs for every trim, plus recall information and competitor comparisons.

2015 GMC Sierra K15 Specifications

SpecValue
Combined MPG17–19 combined MPG depending on trim
City MPG17
Highway MPG22
Body StyleTruck
Fuel TypeFlex Fuel
Drive4WD
Available Trims4

Available Trims

TrimMPG (City/Hwy/Combined)EngineTransmission
Auto16/22/185.3L 8cylAutomatic 6-spd
Auto16/22/185.3L 8cylAutomatic 6-spd
Auto17/22/194.3L 6cylAutomatic 6-spd
Auto15/21/176.2L 8cylAutomatic 8-spd

Annual Fuel Cost

Based on EPA estimates, the 2015 GMC Sierra K15 costs approximately $2,450 per year in fuel. This assumes 15,000 miles driven annually and current fuel prices.

Compare the 2015 GMC Sierra K15

See how it stacks up against similar vehicles:

Other Model Years

Check Vehicle History

Considering a used GMC Sierra K15? Get a comprehensive vehicle history report including accident records, ownership history, and more.

🔍 Check GMC Sierra K15 Vehicle History Check VIN →
Check Vehicle History

Get the full story — accidents, ownership, recalls, odometer, and more. Decode any VIN instantly.

Check VIN
Buying a used GMC Sierra K15? Check VIN on RedVIN