The current Mercedes-Benz GLS covers up to 1,098 km on a full tank, based on combined-cycle consumption. Figures below are the best-range variant in each generation.
| Years | Powertrain | Range |
|---|---|---|
| 2015–2019 | Combustion | 1,299 |
| 2019–2023 | Combustion | 1,268 |
| 2023–present | Combustion | 1,098 |
Range is calculated from each variant’s fuel tank capacity and combined-cycle consumption (tank ÷ consumption × 100), for the best-range variant in each generation — real-world range varies with driving style and conditions. Figures outside a plausible range for the tank size are excluded.