2026 Mercedes-Benz GLS-Class — Full Specifications
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The 2026 Mercedes-Benz GLS-Class is an SUV offered with 2 engines (3L 6-cyl twin-charged, 4L 8-cyl turbo). Its most fuel-efficient configuration returns around 25 mpg (UK) / 21 mpg (US EPA) combined, with 20–25 mpg (UK) across all configurations. Owners often keep a Mercedes-Benz GLS-Class workshop manual to hand for servicing and repairs.
Compared with the 2025 Mercedes-Benz GLS-Class: Fuel economy is essentially unchanged at around 25 mpg (UK) combined. The engine line-up listed by EPA is unchanged.
Full Specifications
| Engine (most efficient) | 3L 6-cyl twin-charged |
|---|---|
| Engine options | 3L 6-cyl twin-charged · 4L 8-cyl turbo |
| Transmission (most efficient) | Automatic 9-spd |
| Fuel Type | Premium Gasoline |
| Powertrain | Hybrid |
| Drive | All-Wheel Drive |
| Body Style | SUV |
| Fuel Economy (UK) | 25 combined / 23 urban / 29 extra-urban mpg |
| Fuel Economy (US EPA) | 21 combined / 19 city / 24 highway mpg |
| CO₂ Emissions | 266 g/km |
| EPA Greenhouse Gas Score | 3 / 10 (10 = lowest emissions) |
| EPA Est. Annual Fuel Cost | $3,900 (15,000 mi/yr, US prices) |
Engine & Transmission Options
EPA lists 2 configurations for the 2026 Mercedes-Benz GLS-Class across 2 engines (3L 6-cyl twin-charged, 4L 8-cyl turbo). Combined fuel economy ranges from 17 to 21 mpg (US), or 20 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 |
|---|---|---|---|---|---|---|
| 3L 6-cyl twin-charged (Hybrid) | Automatic 9-spd | All-Wheel Drive | 25 | 21 (19/24) | 266 | $3,900 |
| 4L 8-cyl turbo (Hybrid) | Automatic 9-spd | All-Wheel Drive | 20 | 17 (15/20) | 334 | $4,850 |
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 2026 Mercedes-Benz GLS-Class
Running Costs: 2026 Mercedes-Benz GLS-Class
Covering around 8,000 miles a year in a 2026 Mercedes-Benz GLS-Class at 25 mpg combined, expect roughly 1,455 litres of fuel annually — multiply by your local price per litre for a cost estimate. For US owners, the EPA estimates about $3,900 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.
2026 Mercedes-Benz GLS-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.
How It Compares
How does the Mercedes-Benz GLS-Class compare to similar SUVs? For context, SUVs in our database average around 27 mpg (UK) combined — this model's 25 mpg figure is 2 mpg below that average. Its 266 g/km CO₂ figure is 13 g/km higher than the 253 g/km average for SUVs on this site. This comparison is based on 1824 SUVs in our dataset.
At 25 mpg (UK) combined it sits close to the 26 mpg average for Mercedes-Benz models in our database.
Of the 10 Mercedes-Benz GLS-Class model years we cover, the 2026 is the most economical on its best configuration (25 mpg UK combined). See every Mercedes-Benz GLS-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 2026 Mercedes-Benz GLS-Class
Frequently Asked Questions
What engine does the 2026 Mercedes-Benz GLS-Class have?
EPA lists 2 engines for the 2026 Mercedes-Benz GLS-Class: 3L 6-cyl twin-charged, 4L 8-cyl turbo. The most fuel-efficient configuration pairs the 3L 6-cyl twin-charged with a automatic 9-spd.
What is the fuel economy of the 2026 Mercedes-Benz GLS-Class?
The most efficient configuration returns around 25 mpg (UK) combined, or 21 mpg on the US EPA cycle. Across all configurations the UK combined figure runs from 20 to 25 mpg.
How much does the 2026 Mercedes-Benz GLS-Class cost to fuel per year?
The US EPA estimates about $3,900 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.
Is the Mercedes-Benz GLS-Class's fuel economy good for an SUV?
It returns around 25 mpg (UK) combined, against a same-body-style average of roughly 27 mpg among the SUVs we track.