⚠️ Mercedes-Benz manufacturer position
XENTRY covers large SUV tank drop with supplemental support. Maybach GLS shares fuel system architecture.
Vehicle information
| Make | Mercedes-Benz |
|---|---|
| Model | GLS |
| Market status | Sold new in the US 2017–present (GLS); GL predecessor |
| Body styles | Full-size SUV |
| Generations | X167 (2020+); X166 (2017–2019 GLS) |
| Engine options | Gasoline: 3.0L turbo I6 (inline-six); 4.0L V8 AMG Diesel: GLS 350d / 450d on select US years |
| Fuel tank capacity | 26.4 gal (100 L) approximate—varies by model year |
| Fuel system | Gasoline direct injection; diesel BlueTEC on equipped models |
| Access method | Cargo-area pump access when available | Tank drop common for full drain |
| Anti-siphon | Yes |
| Service portal | Mercedes-Benz XENTRY / Star TekInfo |
Misfuel risk Moderate
Three-row family SUV with large tank—early drain critical before starting on diesel trims.
If the engine was not started
Do not start large-displacement engines on wrong fuel—tow for drain if needed.
If the engine was started
High repair cost on AMG and diesel common-rail—document contamination for insurance.
Access procedure
- Relieve fuel system pressure and disconnect the negative battery cable.
- Drain accessible fuel through the pump module opening when OEM allows; otherwise prepare for tank removal.
- Raise the vehicle safely; support the fuel tank with OEM-approved equipment.
- Disconnect filler neck, vent, EVAP, and supply/return lines at the tank.
- Lower the tank and empty remaining fuel into approved containers.
- Flush or replace components per contamination severity and OEM limits.
- Reinstall the tank, reconnect all lines, and torque fasteners to specification.
- Refill, prime, and verify fuel pressure and leak-free operation (Mercedes-Benz service information).
Notes
- US GLS 450 gasoline is common—do not assume diesel without label check.
Related models
- GLE
- GL-Class
- Maybach GLS
Frequently asked questions
GLS vs GL—same fuel tank?
X167 GLS replaced GL-Class naming; use current XENTRY for your VIN, not outdated GL-only guides.
How big is the GLS fuel tank?
Roughly 26 gal on many US models—consult OEM for exact capacity when calculating contaminated volume for disposal.
Maybach GLS misfuel?
Maybach trim uses the same fuel system service procedures as GLS—follow XENTRY GLS sections.
Need professional misfuel recovery?
Find a certified operator or read consumer guidance for your next steps.
Find an operator Consumer guidance