2012 GMC Sierra — Full Specifications
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The 2012 GMC Sierra is a pickup offered with 5 engines (4.3L 6-cyl, 4.8L 8-cyl, 5.3L 8-cyl). Its most fuel-efficient configuration returns around 22 mpg (UK) / 18 mpg (US EPA) combined, with 17–25 mpg (UK) across all configurations. A hybrid version is also listed by EPA (6L 8-cyl), returning around 25 mpg (UK) combined. Owners often keep a GMC Sierra workshop manual to hand for servicing and repairs.
Related 2012 listings: GMC Sierra C15, GMC Sierra K15.
Compared with the 2011 GMC Sierra: Fuel economy improves from 20 to 22 mpg (UK) combined on the most efficient configuration. The engine line-up listed by EPA is unchanged. It carries the same 4★ overall NHTSA rating.
Full Specifications
| Engine (most efficient) | 5.3L 8-cyl |
|---|---|
| Engine options | 4.3L 6-cyl · 4.8L 8-cyl · 5.3L 8-cyl · 6L 8-cyl · 6.2L 8-cyl |
| Transmission (most efficient) | Automatic 6-spd |
| Fuel Type | Regular Gasoline |
| Powertrain | Conventional |
| Drive | Rear-Wheel Drive |
| Body Style | Pickup |
| Fuel Economy (UK) | 22 combined / 18 urban / 26 extra-urban mpg |
| Fuel Economy (US EPA) | 18 combined / 15 city / 22 highway mpg |
| CO₂ Emissions | 307 g/km |
| EPA Est. Annual Fuel Cost | $3,700 (15,000 mi/yr, US prices) |
Engine & Transmission Options
EPA lists 10 configurations for the 2012 GMC Sierra across 5 engines (4.3L 6-cyl, 4.8L 8-cyl, 5.3L 8-cyl, 6L 8-cyl). Combined fuel economy ranges from 14 to 21 mpg (US), or 17 to 25 mpg (UK), depending on engine, transmission and drive. The headline figures at the top of this page describe the most fuel-efficient configuration.
| Engine | Transmission | Drive | MPG (UK) | MPG (US) | CO₂ g/km | Fuel cost / yr |
|---|---|---|---|---|---|---|
| 4.3L 6-cyl | Automatic 4-spd | 4-Wheel Drive | 19 | 16 (14/18) | 345 | $4,200 |
| 4.3L 6-cyl | Automatic 4-spd | Rear-Wheel Drive | 20 | 17 (15/20) | 325 | $3,950 |
| 4.8L 8-cyl | Automatic 4-spd | 4-Wheel Drive | 18 | 15 (13/18) | 368 | $4,450 |
| 4.8L 8-cyl | Automatic 4-spd | Rear-Wheel Drive | 19 | 16 (14/19) | 345 | $4,200 |
| 5.3L 8-cyl | Automatic 6-spd | 4-Wheel Drive | 20 | 17 (15/21) | 325 | $3,950 |
| 5.3L 8-cyl | Automatic 6-spd | Rear-Wheel Drive | 22 | 18 (15/22) | 307 | $3,700 |
| 6L 8-cyl (Hybrid) | Automatic (variable gear ratios) | 4-Wheel Drive | 25 | 21 (20/23) | 263 | $3,200 |
| 6L 8-cyl (Hybrid) | Automatic (variable gear ratios) | Rear-Wheel Drive | 25 | 21 (20/23) | 263 | $3,200 |
| 6.2L 8-cyl | Automatic 6-spd | 4-Wheel Drive | 17 | 14 (12/18) | 394 | $4,800 |
| 6.2L 8-cyl | Automatic 6-spd | Rear-Wheel Drive | 17 | 14 (13/18) | 394 | $4,800 |
MPG (US) shows combined, with city/highway in brackets. Highlighted row = the configuration used for the headline figures. Source: US EPA fueleconomy.gov.
Owner Essentials for the 2012 GMC Sierra
Running Costs: 2012 GMC Sierra
Covering around 8,000 miles a year in a 2012 GMC Sierra at 22 mpg combined, expect roughly 1,653 litres of fuel annually — multiply by your local price per litre for a cost estimate. For US owners, the EPA estimates about $3,700 a year in fuel for the most efficient configuration (15,000 miles, national average prices). Work out exact fuel costs with the fuel cost calculator on 247Calculators.
Convert between MPG and L/100km with the unit converters on 247QuickTools. Not sure what tyre size fits? 247TyreCheck explains tyre sizing.
Only need this car occasionally? See our buy vs rent comparison.
2012 GMC Sierra Safety Ratings (NHTSA)
Recalls & Owner Complaints (NHTSA)
NHTSA lists 4 safety recall campaigns that include the 2012 GMC Sierra (as of 6 October 2026). Most affected areas: Air bags (2), Equipment (1), Fuel system (1). A campaign often covers several model years or models, so check your own VIN to see whether your car is affected.
- Air bags — campaign 21V054000, reported 5 February 2021. Risk: An inflator explosion may result in sharp metal fragments striking the driver or other occupants, resulting in serious injury or death.
- Air bags — campaign 21V051000, reported 5 February 2021. Risk: An inflator explosion may result in sharp metal fragments striking the driver or other occupants, resulting in serious injury or death.
- Equipment — campaign 18V267000, reported 26 April 2018. Risk: In the event of a fire, if the fire extinguisher does not function properly, it can increase the risk of injury.
- Fuel system — campaign 17V664000, reported 19 October 2017. Risk: If the front tank overfills, the excess pressure may cause the front tank to expand and contact the driveshaft, possibly resulting in a hole in the tank. The hole will leak fuel, which in the presence of an…
Owners have filed 192 complaints with NHTSA about the 2012 GMC Sierra. The most-reported areas are Air bags (57), Unspecified (54), Structure (35). Complaints include 9 reported crashes, 2 reported fires, 6 reported injuries, 1 reported death. That is well below the median of 479 complaints across the 17 GMC Sierra model years in our data.
Used-buyer checklist for the 2012 GMC Sierra
Based on where NHTSA recalls and owner complaints cluster for this model year, these are the areas worth checking before you buy:
- Air bags (2 recall campaigns · 57 owner complaints) — Confirm any air bag inflator or module recalls were completed — enter the VIN at nhtsa.gov/recalls.
- Body structure (35 owner complaints) — Inspect for corrosion and for subframe or body-panel damage, especially underneath.
- Electrical system (22 owner complaints) — Test every switch, window, light and warning lamp on a test drive, and ask about battery or alternator replacements.
- Fuel system (1 recall campaign) — Ask whether any fuel-pump or fuel-system recalls were completed, and watch for hard starting or stalling.
Source: US NHTSA recall and consumer-complaint databases, retrieved 6 October 2026. Complaints are unverified owner reports, not confirmed defects. Check any vehicle by VIN at nhtsa.gov/recalls, and see our guide to checking a used car for recalls.
How It Compares
How does the GMC Sierra compare to similar pickups? For context, pickups in our database average around 25 mpg (UK) combined — this model's 22 mpg figure is 3 mpg below that average. Its 307 g/km CO₂ figure is 24 g/km higher than the 283 g/km average for pickups on this site. This comparison is based on 264 pickups in our dataset.
GMC models in our database average about 26 mpg (UK) combined on their most efficient configuration; the 2012 GMC Sierra's 22 mpg is 4 mpg below that make average. Its 307 g/km CO₂ figure is 35 g/km higher than the 272 g/km GMC average.
Of the 17 GMC Sierra model years we cover, the 2012 ranks 14th for combined fuel economy on its best configuration (22 mpg UK combined, against a high of 31 mpg). See every GMC Sierra year side by side.
Last updated: · Data: US EPA (fueleconomy.gov) and NHTSA safety ratings 18 July 2026; NHTSA recalls and complaints 6 October 2026; Wikidata & curated EU catalogue 18 July 2026; European generation and engine data from Wikipedia 7 October 2026
Vehicle data sourced from manufacturer specifications. Always verify with your vehicle handbook or a qualified mechanic. This is a reference tool, not professional advice.
Recommended Accessories for the 2012 GMC Sierra
Frequently Asked Questions
What engine does the 2012 GMC Sierra have?
EPA lists 5 engines for the 2012 GMC Sierra: 4.3L 6-cyl, 4.8L 8-cyl, 5.3L 8-cyl, 6L 8-cyl, 6.2L 8-cyl. The most fuel-efficient configuration pairs the 5.3L 8-cyl with a automatic 6-spd.
What is the fuel economy of the 2012 GMC Sierra?
The most efficient configuration returns around 22 mpg (UK) combined, or 18 mpg on the US EPA cycle. Across all configurations the UK combined figure runs from 17 to 25 mpg. The hybrid version returns around 25 mpg (UK) combined.
How much does the 2012 GMC Sierra cost to fuel per year?
The US EPA estimates about $3,700 a year in fuel for the most efficient configuration, based on 15,000 miles of mixed driving and national average fuel prices. Your own cost will depend on mileage and local prices.
Does the 2012 GMC Sierra have a good safety rating?
It holds an overall NHTSA rating of 4 stars, with 4 stars for frontal crash protection.
Does the 2012 GMC Sierra have any recalls?
NHTSA lists 4 safety recall campaigns that include the 2012 GMC Sierra (as of 6 October 2026). Most affected areas: Air bags (2), Equipment (1), Fuel system (1). A campaign often covers several model years or models, so check your own VIN to see whether your car is affected.
What are the most common problems reported for the 2012 GMC Sierra?
Among the 192 owner complaints filed with NHTSA, the most-reported areas are Air bags (57 complaints), Unspecified (54 complaints), Structure (35 complaints). Complaints are unverified owner reports, not confirmed defects, and raw counts rise with how many cars were sold.
Is the GMC Sierra's fuel economy good for a pickup?
It returns around 22 mpg (UK) combined, against a same-body-style average of roughly 25 mpg among the pickups we track.