EPA ratings · 2012 · GMC · Sierra
2012 GMC Sierra Fuel Economy
EPA rates the 2012 GMC Sierra's 12 trims from 14 to 21 MPG combined, Sierra C15 2WD to Sierra 15 Hybrid 2WD. The table below prices every trim per mile at a fuel price and mileage you can change.
EPA ratings by trim
| Trim | Engine | Transmission | Drive | City | Hwy | Combined |
|---|---|---|---|---|---|---|
| Sierra 15 Hybrid 2WD · Regular | 6 L, 8 cyl, Hybrid | Automatic (variable gear ratios) | Rear-Wheel Drive | 20 | 23 | 21 MPG |
| Sierra 15 Hybrid 4WD · Regular | 6 L, 8 cyl, Hybrid | Automatic (variable gear ratios) | 4-Wheel Drive | 20 | 23 | 21 MPG |
| Sierra C15 2WD · Gasoline or E85 | 5.3 L, 8 cyl, FFV | Automatic 6-spd | Rear-Wheel Drive | 15 | 21 | 17 MPG |
| Sierra C15 2WD · Gasoline or E85 | 6.2 L, 8 cyl, FFV | Automatic 6-spd | Rear-Wheel Drive | 13 | 18 | 14 MPG |
| Sierra C15 2WD · Regular | 4.3 L, 6 cyl | Automatic 4-spd | Rear-Wheel Drive | 15 | 20 | 17 MPG |
| Sierra C15 2WD · Gasoline or E85 | 4.8 L, 8 cyl, FFV | Automatic 4-spd | Rear-Wheel Drive | 14 | 19 | 16 MPG |
| Sierra C15 XFE 2WD · Gasoline or E85 | 5.3 L, 8 cyl, FFV | Automatic 6-spd | Rear-Wheel Drive | 15 | 22 | 18 MPG |
| Sierra K15 4WD · Gasoline or E85 | 5.3 L, 8 cyl, FFV | Automatic 6-spd | 4-Wheel Drive | 15 | 21 | 17 MPG |
| Sierra K15 4WD · Gasoline or E85 | 6.2 L, 8 cyl, FFV | Automatic 6-spd | 4-Wheel Drive | 12 | 18 | 14 MPG |
| Sierra K15 4WD · Regular | 4.3 L, 6 cyl | Automatic 4-spd | 4-Wheel Drive | 14 | 18 | 16 MPG |
| Sierra K15 4WD · Gasoline or E85 | 4.8 L, 8 cyl, FFV | Automatic 4-spd | 4-Wheel Drive | 13 | 18 | 15 MPG |
| Sierra K15 AWD · Gasoline or E85 | 6.2 L, 8 cyl, FFV | Automatic 6-spd | 4-Wheel Drive | 12 | 18 | 14 MPG |
City and highway are EPA's adjusted label figures; combined is the 55/45 blend printed on the window sticker. For electric and plug-in trims the MPG columns are MPGe, and the kWh per 100 miles is the figure a charging cost actually turns on; EPA measures it at the wall, so charging losses are already in it. Unrounded combined figures, where EPA publishes them: Sierra 15 Hybrid 2WD 21.0782; Sierra 15 Hybrid 4WD 20.9446; Sierra C15 2WD 16.9631; Sierra C15 2WD 14.4288; Sierra C15 2WD 17.0223; Sierra C15 2WD 15.8411; Sierra C15 XFE 2WD 17.7765; Sierra K15 4WD 16.9588; Sierra K15 4WD 14.1791; Sierra K15 4WD 15.5214; Sierra K15 4WD 14.8693; Sierra K15 AWD 14.2021.
What the rating costs per mile
The rating divided by a price, times your miles. It starts at EIA's current U.S. averages and EPA's 15,000 miles so the right-hand column is comparable; type your own pump price, home rate and mileage over them.
| Trim | Runs on | Rated | Per mile | Per year | EPA's figure |
|---|---|---|---|---|---|
| Sierra 15 Hybrid 2WD | Regular Gasoline | 21 MPG | 20.4¢ | $3,060 | $3,200 |
| Sierra 15 Hybrid 4WD | Regular Gasoline | 21 MPG | 20.4¢ | $3,060 | $3,200 |
| Sierra C15 2WD | Regular Gasoline | 17 MPG | 25.2¢ | $3,780 | $3,950 |
| Sierra C15 2WD | Regular Gasoline | 14 MPG | 30.6¢ | $4,590 | $4,800 |
| Sierra C15 2WD | Regular Gasoline | 17 MPG | 25.2¢ | $3,780 | $3,950 |
| Sierra C15 2WD | Regular Gasoline | 16 MPG | 26.8¢ | $4,016 | $4,200 |
| Sierra C15 XFE 2WD | Regular Gasoline | 18 MPG | 23.8¢ | $3,570 | $3,700 |
| Sierra K15 4WD | Regular Gasoline | 17 MPG | 25.2¢ | $3,780 | $3,950 |
| Sierra K15 4WD | Regular Gasoline | 14 MPG | 30.6¢ | $4,590 | $4,800 |
| Sierra K15 4WD | Regular Gasoline | 16 MPG | 26.8¢ | $4,016 | $4,200 |
| Sierra K15 4WD | Regular Gasoline | 15 MPG | 28.6¢ | $4,284 | $4,450 |
| Sierra K15 AWD | Regular Gasoline | 14 MPG | 30.6¢ | $4,590 | $4,800 |
Per mile = price ÷ rated MPG (gasoline) or price per kWh × kWh per 100 miles ÷ 100 (electricity). Per year = per mile × miles. EPA's figure is its own annual fuel cost at 15,000 miles, 55% city, and the national price in force when the file was built; it will differ from the middle columns whenever the price here differs. A plug-in hybrid is shown once on each fuel; its real cost sits between them, by how much of its driving is on the battery.
Fuel only — before depreciation, insurance, maintenance or tires, which the True Cost per Mile Calculator adds. Most drivers land below the rating; the True MPG Calculator measures your own from two fill-ups.
EPA's own figures, and why they differ
The “EPA's figure” column is EPA's annual fuel cost from the same file: 15,000 miles, 55% city, and the national fuel price fueleconomy.gov was using on the day the file was built (2026-09-29). fueleconomy.gov recomputes its page every week at the current price, so its number and the file's drift apart between file dates; the middle columns here use a price you can see and change, which is the only honest way to compare two cars. EPA also prints a five-year “you save/spend” against the average new vehicle (spends $4,000 for the Sierra 15 Hybrid 2WD); it rests on the same assumptions and is not repeated here as a result.
Every figure on this page is a rating, not a measurement of any particular car. The site never calls a rating wrong; it shows what your own price and miles do to it. See the model on fueleconomy.gov.
Other model years of the GMC Sierra: 2026, 2025, 2024, 2023, 2022, 2021, 2020, 2019, 2018, 2017, 2016, 2015, 2014, 2013, 2011, 2010, 2009, 2008, 2007, 2006, 2005, 2004, 2003, 2002, 2001, 2000, 1999, 1998, 1997, 1996, 1995, 1994, 1993, 1992, 1991, 1990, 1989.
Related tools
Price the same miles on gasoline and on electricity, using your fuel price, your utility rate, and each car's rated efficiency.
Open tool →True MPG CalculatorYour car's real fuel economy from two odometer readings and a fill-up — and how far it falls from its EPA rating.
Open tool →Commute Cost CalculatorWhat getting to work costs per day, per month, and per year — energy only, or all-in at the IRS standard mileage rate.
Open tool →Gas Prices by Region and StateThis week's average price of regular gasoline for the U.S., every state and ten cities, from EIA's weekly survey — a dated figure to start from, never one assumed for you.
Open tool →Electricity Prices by StateThe average residential price of electricity in every state, by month, from EIA's utility filings — and what each rate does to a mile in an electric car.
Open tool →Informational only — published averages for scale and comparison, not a quote for any pump, utility or vehicle. Your own price is the one that counts, and every calculator on this site takes it as an input.
Ratings: U.S. EPA and U.S. DOE, fueleconomy.gov vehicles.csv dated 2026-09-29 (EPA record ids 31857, 31864, 31443, 31444, 31445, 31446, 31442, 31452, 31453, 31454, 31455, 31456). Prices: EIA, U.S. regular gasoline week of October 19, 2026; U.S. residential electricity August 2026. Snapshots refreshed monthly.