The 2021 Mercedes-Benz GLS delivers an EPA-certified 16–21 MPG combined across 4 configurations. Estimated annual fuel costs range from $3,600 to $4,750.
Laboratory certification test values across engine, transmission, and drivetrain permutations
| Configuration / Model | Powertrain | Drivetrain | Transmission | City | Highway | Combined | Annual Fuel Cost | CO2 (g/mi) |
|---|---|---|---|---|---|---|---|---|
| GLS450 4matic Premium | 3L Hybrid | 4-Wheel Drive | Automatic 9-spd | 20 MPG | 24 MPG | 21 MPG | $3,600 | — |
| GLS580 4matic Premium | 4L Hybrid | 4-Wheel Drive | Automatic 9-spd | 16 MPG | 21 MPG | 18 MPG | $4,200 | — |
| AMG GLS63 4matic Plus Premium | 4L Hybrid | 4-Wheel Drive | Automatic 9-spd | 14 MPG | 18 MPG | 16 MPG | $4,750 | — |
| GLS600 4matic Maybach Premium | 4L Hybrid | 4-Wheel Drive | Automatic 9-spd | 15 MPG | 19 MPG | 16 MPG | $4,750 | — |
Standardized annual energy consumption and operating cost metrics based on 15,000 annual miles
Based on $3.50 per gallon regular gasoline
Estimated annual energy units needed for 15,000 miles
Compared to the average new vehicle over 5 years
Cross-reference safety ratings, owner defect complaints, and recall campaigns
Vehicle summary, specifications, and primary KPI metrics.
NHTSA 5-Star NCAP crash tests, rollover risk, and active driver assistance.
NHTSA consumer defect complaint filings by affected component.
Official safety recall notices, defects, and free repair instructions.
Direct, deterministic answers synthesized from verified United States government databases for the 2021 Mercedes-Benz GLS
The 2021 Mercedes-Benz GLS achieves an EPA-certified rating of 16 to 21 MPG combined across 4 certified configuration(s).
City ratings range from 14 to 20 MPG, and highway ratings range from 18 to 24 MPG.
Using AutoUtility's standardized operating cost model, estimated annual fueling and energy costs range between $3,600 and $4,750 for the 2021 Mercedes-Benz GLS.
Calculated under AutoUtility's standardized methodology (15,000 miles per year, 55% city / 45% highway driving, $3.50/gallon regular gasoline, $0.16/kWh electricity) using official EPA dynamometer consumption ratings.
Fuel economy ratings, electric range figures, and energy cost estimates on this page are retrieved directly from the United States Environmental Protection Agency (EPA) and U.S. Department of Energy (FuelEconomy.gov) certified vehicle database under 40 CFR Part 600.
Local Production Store Compiled: August 2026 • Deterministic Audited Dataset • Zero Dynamic External API Runtime Latency.