2021 Mercedes-Benz G-Class — Full Specifications
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The 2021 Mercedes-Benz G-Class is an SUV powered by a 4L 8-cyl turbo premium gasoline engine. It returns around 17 mpg (UK) / 14 mpg (US EPA) combined. Owners often keep a Mercedes-Benz G-Class workshop manual to hand for servicing and repairs.
Compared with the 2020 Mercedes-Benz G-Class: Fuel economy is essentially unchanged at around 17 mpg (UK) combined. The engine line-up listed by EPA is unchanged.
Full Specifications
| Engine | 4L 8-cyl turbo |
|---|---|
| Transmission | Automatic 9-spd |
| Fuel Type | Premium Gasoline |
| Powertrain | Conventional |
| Drive | 4-Wheel Drive |
| Body Style | SUV |
| Fuel Economy (UK) | 17 combined / 16 urban / 19 extra-urban mpg |
| Fuel Economy (US EPA) | 14 combined / 13 city / 16 highway mpg |
| CO₂ Emissions | 396 g/km |
| EPA Greenhouse Gas Score | 1 / 10 (10 = lowest emissions) |
| EPA Est. Annual Fuel Cost | $5,850 (15,000 mi/yr, US prices) |
Engine & Transmission Options
EPA lists 1 configuration for the 2021 Mercedes-Benz G-Class, all with the 4L 8-cyl turbo engine. 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 |
|---|---|---|---|---|---|---|
| 4L 8-cyl turbo | Automatic 9-spd | 4-Wheel Drive | 17 | 14 (13/16) | 396 | $5,850 |
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 2021 Mercedes-Benz G-Class
Running Costs: 2021 Mercedes-Benz G-Class
Covering around 8,000 miles a year in a 2021 Mercedes-Benz G-Class at 17 mpg combined, expect roughly 2,139 litres of fuel annually — multiply by your local price per litre for a cost estimate. For US owners, the EPA estimates about $5,850 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.
Planning a road trip? Grab a road trip packing list. Only need this car occasionally? See our buy vs rent comparison.
2021 Mercedes-Benz G-Class Safety Ratings (NHTSA)
No NHTSA crash-test rating is on record for this model year. The NHTSA rates only a subset of vehicles each year; you can browse every rated vehicle on our NHTSA Safety Ratings hub.
Recalls & Owner Complaints (NHTSA)
NHTSA lists no safety recall campaigns for the 2021 Mercedes-Benz G-Class as of 6 October 2026. Recalls can be issued years after a model is sold, so it is still worth checking your own VIN.
Owners have filed 7 complaints with NHTSA about the 2021 Mercedes-Benz G-Class. The most-reported areas are Electrical system (4), Engine (3), Fuel/propulsion system (2). Complaints include 1 reported crash, 1 reported fire, 15 reported injuries.
Used-buyer checklist for the 2021 Mercedes-Benz G-Class
Based on where NHTSA recalls and owner complaints cluster for this model year, these are the areas worth checking before you buy:
- Electrical system (4 owner complaints) — Test every switch, window, light and warning lamp on a test drive, and ask about battery or alternator replacements.
- Engine (3 owner complaints) — Listen for unusual noise on a cold start, check for warning lights and ask for the service records.
- Fuel system (2 owner complaints) — Ask whether any fuel-pump or fuel-system recalls were completed, and watch for hard starting or stalling.
- Air bags (1 owner complaint) — Confirm any air bag inflator or module recalls were completed — enter the VIN at nhtsa.gov/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 Mercedes-Benz G-Class compare to similar SUVs? For context, SUVs in our database average around 27 mpg (UK) combined — this model's 17 mpg figure is 10 mpg below that average. Its 396 g/km CO₂ figure is 143 g/km higher than the 253 g/km average for SUVs on this site. This comparison is based on 1824 SUVs in our dataset.
Mercedes-Benz models in our database average about 26 mpg (UK) combined on their most efficient configuration; the 2021 Mercedes-Benz G-Class's 17 mpg is 9 mpg below that make average. Its 396 g/km CO₂ figure is 128 g/km higher than the 268 g/km Mercedes-Benz average.
Of the 17 Mercedes-Benz G-Class model years we cover, the 2021 ranks 4th for combined fuel economy on its best configuration (17 mpg UK combined, against a high of 22 mpg). See every Mercedes-Benz G-Class 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 2021 Mercedes-Benz G-Class
Frequently Asked Questions
What engine does the 2021 Mercedes-Benz G-Class have?
It's fitted with a 4L 8-cyl turbo premium gasoline engine, paired with a automatic 9-spd transmission.
What is the fuel economy of the 2021 Mercedes-Benz G-Class?
The most efficient configuration returns around 17 mpg (UK) combined, or 14 mpg on the US EPA cycle.
How much does the 2021 Mercedes-Benz G-Class cost to fuel per year?
The US EPA estimates about $5,850 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 2021 Mercedes-Benz G-Class have any recalls?
NHTSA lists no safety recall campaigns for the 2021 Mercedes-Benz G-Class as of 6 October 2026. Recalls can be issued years after a model is sold, so it is still worth checking your own VIN.
What are the most common problems reported for the 2021 Mercedes-Benz G-Class?
Among the 7 owner complaints filed with NHTSA, the most-reported areas are Electrical system (4 complaints), Engine (3 complaints), Fuel/propulsion system (2 complaints). Complaints are unverified owner reports, not confirmed defects, and raw counts rise with how many cars were sold.
Is the Mercedes-Benz G-Class's fuel economy good for an SUV?
It returns around 17 mpg (UK) combined, against a same-body-style average of roughly 27 mpg among the SUVs we track.