2025 GMC Sierra — Full Specifications
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The 2025 GMC Sierra is a pickup offered with 4 engines (2.7L 4-cyl turbo, 3L 6-cyl turbo, 5.3L 8-cyl). Its most fuel-efficient configuration returns around 31 mpg (UK) / 26 mpg (US EPA) combined, with 19–31 mpg (UK) across all configurations. Owners often keep a GMC Sierra workshop manual to hand for servicing and repairs.
Compared with the 2024 GMC Sierra: Fuel economy is essentially unchanged at around 31 mpg (UK) combined. The engine line-up listed by EPA is unchanged. It carries the same 5★ overall NHTSA rating.
Full Specifications
| Engine (most efficient) | 3L 6-cyl turbo |
|---|---|
| Engine options | 2.7L 4-cyl turbo · 3L 6-cyl turbo · 5.3L 8-cyl · 6.2L 8-cyl |
| Transmission (most efficient) | Automatic 10-spd |
| Fuel Type | Diesel |
| Powertrain | Conventional |
| Drive | Rear-Wheel Drive |
| Body Style | Pickup |
| Fuel Economy (UK) | 31 combined / 28 urban / 35 extra-urban mpg |
| Fuel Economy (US EPA) | 26 combined / 23 city / 29 highway mpg |
| CO₂ Emissions | 248 g/km |
| EPA Greenhouse Gas Score | 3 / 10 (10 = lowest emissions) |
| EPA Est. Annual Fuel Cost | $3,700 (15,000 mi/yr, US prices) |
Engine & Transmission Options
EPA lists 8 configurations for the 2025 GMC Sierra across 4 engines (2.7L 4-cyl turbo, 3L 6-cyl turbo, 5.3L 8-cyl, 6.2L 8-cyl). Combined fuel economy ranges from 16 to 26 mpg (US), or 19 to 31 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 |
|---|---|---|---|---|---|---|
| 2.7L 4-cyl turbo | Automatic 8-spd | 4-Wheel Drive | 20 | 17 (17/18) | 321 | $3,950 |
| 2.7L 4-cyl turbo | Automatic 8-spd | Rear-Wheel Drive | 23 | 19 (18/21) | 291 | $3,550 |
| 3L 6-cyl turbo | Automatic 10-spd | 4-Wheel Drive | 29 | 24 (22/26) | 266 | $4,000 |
| 3L 6-cyl turbo | Automatic 10-spd | Rear-Wheel Drive | 31 | 26 (23/29) | 248 | $3,700 |
| 5.3L 8-cyl | Automatic 10-spd | 4-Wheel Drive | 20 | 17 (15/19) | 326 | $3,950 |
| 5.3L 8-cyl | Automatic 10-spd | 4-Wheel Drive | 19 | 16 (15/19) | 339 | $4,200 |
| 5.3L 8-cyl | Automatic 10-spd | Rear-Wheel Drive | 22 | 18 (16/21) | 308 | $3,700 |
| 6.2L 8-cyl | Automatic 10-spd | 4-Wheel Drive | 19 | 16 (15/19) | 335 | $5,500 |
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 2025 GMC Sierra
Running Costs: 2025 GMC Sierra
Covering around 8,000 miles a year in a 2025 GMC Sierra at 31 mpg combined, expect roughly 1,173 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.
2025 GMC Sierra Safety Ratings (NHTSA)
Recalls & Owner Complaints (NHTSA)
NHTSA lists 3 safety recall campaigns that include the 2025 GMC Sierra (as of 6 October 2026). Most affected areas: Tires (1), Equipment adaptive/mobility (1), Seat belts (1). A campaign often covers several model years or models, so check your own VIN to see whether your car is affected.
- Tires — campaign 26V530000, reported 13 August 2026. Risk: Driving with underinflated tires can increase the risk of a crash.
- Equipment adaptive/mobility — campaign 25V876000, reported 17 December 2025. Risk: An unsecured wheelchair can move during transit, increasing the risk of injury.
- Seat belts — campaign 25V015000, reported 16 January 2025. Risk: An improperly secured seat belt assembly may not restrain an occupant as intended, increasing the risk of injury in a crash.
Owners have filed 153 complaints with NHTSA about the 2025 GMC Sierra. The most-reported areas are Engine (59), Power train (30), Electrical system (27). Complaints include 7 reported crashes, 6 reported injuries. That is well below the median of 479 complaints across the 17 GMC Sierra model years in our data.
Used-buyer checklist for the 2025 GMC Sierra
Based on where NHTSA recalls and owner complaints cluster for this model year, these are the areas worth checking before you buy:
- Engine (59 owner complaints) — Listen for unusual noise on a cold start, check for warning lights and ask for the service records.
- Transmission & drivetrain (30 owner complaints) — On the test drive, watch for hesitation, jerking or slipping between gears and ask for transmission service history.
- Electrical system (27 owner complaints) — Test every switch, window, light and warning lamp on a test drive, and ask about battery or alternator replacements.
- Tyres (1 recall campaign) — Check tyre age and wear and ask about any tyre recalls.
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 31 mpg figure is 6 mpg better than that average. Its 248 g/km CO₂ figure is 35 g/km lower 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 2025 GMC Sierra's 31 mpg is 5 mpg above that make average. Its 248 g/km CO₂ figure is 24 g/km lower than the 272 g/km GMC average.
Of the 17 GMC Sierra model years we cover, the 2025 is the most economical on its best configuration (31 mpg UK combined). 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 2025 GMC Sierra
Frequently Asked Questions
What engine does the 2025 GMC Sierra have?
EPA lists 4 engines for the 2025 GMC Sierra: 2.7L 4-cyl turbo, 3L 6-cyl turbo, 5.3L 8-cyl, 6.2L 8-cyl. The most fuel-efficient configuration pairs the 3L 6-cyl turbo with a automatic 10-spd.
What is the fuel economy of the 2025 GMC Sierra?
The most efficient configuration returns around 31 mpg (UK) combined, or 26 mpg on the US EPA cycle. Across all configurations the UK combined figure runs from 19 to 31 mpg.
How much does the 2025 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 2025 GMC Sierra have a good safety rating?
It holds an overall NHTSA rating of 5 stars, with 4 stars for frontal crash protection.
Does the 2025 GMC Sierra have any recalls?
NHTSA lists 3 safety recall campaigns that include the 2025 GMC Sierra (as of 6 October 2026). Most affected areas: Tires (1), Equipment adaptive/mobility (1), Seat belts (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 2025 GMC Sierra?
Among the 153 owner complaints filed with NHTSA, the most-reported areas are Engine (59 complaints), Power train (30 complaints), Electrical system (27 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?
Yes — it returns around 31 mpg (UK) combined, against a same-body-style average of roughly 25 mpg among the pickups we track, making it one of the more efficient options in its class.