2014 GMC Sierra K15 4WD MPG & Specs — Real-World vs EPA, All Trims
Fuel grade varies by trim — see the breakdown below.
Is the 2014 GMC Sierra K15 4WD good on gas?
At up to 19 MPG combined, the 2014 GMC Sierra K15 4WD is better than average for a Standard Pickup Trucks 4WD — that class averages about 16.5 MPG across 1,581 EPA-tested versions, so it's a good pick on fuel for its size.
Real-world MPG vs the EPA number
The EPA figures above come from a standardized dynamometer test, not the open road — real-world MPG typically runs a bit lower depending on your driving, climate and terrain. That's true of every car on this site, old or new.
EPA updated its fuel-economy equations again for model year 2017 — mostly affecting hybrids and turbocharged engines — and recalculated 2011-2016 ratings to match, in some cases 1-2 MPG lower. The number above already reflects that update.
For its most efficient trim, the EPA estimates about $3,300 a year in fuel (15,000 miles) — roughly $275 a month.
2014 GMC Sierra K15 4WD trims & fuel economy
| Trim (engine / transmission) | Fuel | MPG | Fuel/yr (today's price) |
|---|---|---|---|
| 6.2L 8-cyl, Automatic 6-spd, 4WD | REGULAR | 17 | $3,353 |
| 4.3L 6-cyl, Automatic 6-spd, 4WD | FLEX-FUEL | 19 | $3,300 |
| 5.3L 8-cyl, Automatic 6-spd, 4WD | FLEX-FUEL | 18 | $3,450 |
2014 GMC Sierra K15 4WD specs
What the EPA test-car listings record for this model year — every combination sold is a row in the trims table above.
| Engine options | 6.2L 8-cyl · 4.3L 6-cyl · 5.3L 8-cyl |
| Transmission | Automatic 6-spd |
| Drive type | 4WD |
| EPA body class | Standard Pickup Trucks 4WD |
| Fuel | Varies by trim |
| Tailpipe CO₂ | 474–536 g/mi |
Other years of the GMC Sierra K15 4WD
Similar cars (Standard Pickup Trucks 4WD)
Cars that take premium · Cheapest cars to fuel · Where fuel grade depends on the trim · Fuel guides
3 trim(s) · EPA FuelEconomy.gov data retrieved 2026-07-24 · fuel prices AAA national average as of 2026-07-05.