Against 344 other Hybrid cars rated 2024–2026, the GLS-Class trails their 28 mpg average by 7 mpg, about $458 a year. Averaged over the years each was sold, the most economical engine since 2017, the 3L 6-cyl Hybrid (2020–2026), does 20.7 mpg and the thirstiest, the 4.7L 8-cyl (2017–2019), 16: $545 a year apart.
Every Mercedes-Benz GLS-Class engine, compared
Yearly cost assumes 12,000 miles at $3.20 a gallon.
| Engine | Combined | City / Highway | Years | Fuel per year |
|---|---|---|---|---|
| 3L 6-cyl Hybrid | 18.9 / 23.7 | 2020–2026 | $1,855 | |
| 3L 6-cyl | 16.7 / 22 | 2017–2019 | $2,053 | |
| 4.7L 8-cyl | 14 / 18.7 | 2017–2019 | $2,400 |
What that actually costs
| Measure | Value |
|---|---|
| Cost per mile (2026) | $0.152 |
| Fuel per year | $1,829 |
| Fuel over five years | $9,145 |
| Against other Hybrid cars, 2024–2026 | +$458 a year |
| EPA's own estimate | $4,058 a year |
City or highway — who is this car for
The 2026 Mercedes-Benz GLS-Class gives up 5 mpg in town: 24 on the highway against 19 in the city, $421 a year if every mile were city driving.
| Measure | Value | Reading |
|---|---|---|
| City (2026) | 19 mpg | $2,021 a year if you only drive in town |
| Highway | 24 mpg | $1,600 a year if you mostly commute |
| Gap | +5 mpg (26%) | Typical for its type |
How the GLS-Class changed over the years
The GLS-Class peaked in 2026 at 21 mpg (19 city, 24 highway) and was at its thirstiest in 2019 at 17 — 4 mpg apart, or $430 a year in fuel between buying one year and the other. The biggest single-year change came in 2020: 17 to 21 mpg.
| Model year | Combined | City / Highway | Engines offered | Fuel per year |
|---|---|---|---|---|
| 2026 | 19 / 24 | 1 | $1,829 | |
| 2025 | 19 / 24 | 1 | $1,829 | |
| 2024 | 19 / 24 | 1 | $1,829 | |
| 2023 | 18 / 23 | 1 | $1,920 | |
| 2022 | 18 / 24 | 1 | $1,920 | |
| 2021 | 20 / 24 | 1 | $1,829 | |
| 2020 | 19 / 23 | 1 | $1,829 | |
| 2019 | 15 / 20.5 | 2 | $2,259 | |
| 2018 | 15.5 / 20.5 | 2 | $2,194 | |
| 2017 | 15.5 / 20 | 2 | $2,194 |
MPG is a number. Dollars per year is the answer.
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How we count
This page rests on 13 EPA ratings of the Mercedes-Benz GLS-Class — 3 engines across 2017–2026. The mileage is EPA's laboratory figure, unchanged; the yearly bill is ours, at 12,000 miles and $3.20 a gallon, against EPA's own estimate of $4,058. Full method.
Frequently asked questions
What mpg does the 2026 Mercedes-Benz GLS-Class get?
21 mpg combined, 19 city and 24 highway, per EPA. Across every year since 2017 the GLS-Class has averaged 19.2 mpg.
Is the 2026 GLS-Class more efficient than the 2025?
About the same: 21 against 21 mpg combined.
Which GLS-Class year has the best gas mileage?
The 2026, at 21 mpg combined (19 city, 24 highway), which is also the latest model year we hold.
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