2018 Mercedes-Benz GLS 450 Problems
- Complaints
- 14filed with NHTSA
- Median mileage
- 8,000miles, 7 complaints with mileage
- Recalls
- 3campaigns on record
- Trend
- Not enough dataFewer than 15 complaints, too few for a reliable trend.
- NHTSA crash rating
- —no overall rating published
- EPA fuel economy
- 19 mpgcombined, 3.0L 6-cyl 4WD · 17 city / 22 hwy
Sources: NHTSA records for the 2018 Mercedes-Benz GLS 450 (complaints, recalls, investigations), EPA fuel economy. Report an error
NHTSA recorded 14 consumer complaints for the 2018 Mercedes-Benz GLS 450. The part named most often is brakes, with 3 complaints (21% of the total), followed by suspension (3) and electrical system (2). 7 of the complaints include a mileage, and 100% of those were filed for vehicles with under 50,000 miles; the median is 8,000 miles. Of all complaints, 1 involved a crash, 3 a fire, according to the filers. NHTSA lists 3 recall campaigns and 91 technical service bulletins for this model year. Brakes complaints overlap with 1 recall campaign and 2 technical service bulletins filed under the same part. Suspension complaints overlap with 9 technical service bulletins filed under the same part.
This model year has fewer than 25 complaints on record, so the numbers below can change a lot with a few new reports.
Which parts are reported most
Complaints can name more than one part, so the counts add up to more than the total. Select a part to see its complaints, recalls and bulletins.
- Brakes3 21%
- Suspension3 21%
- Electrical system2 14%
- Engine2 14%
- Body and structure2 14%
- Exterior lighting1 7.1%
- Fuel system1 7.1%
- Other or unknown1 7.1%
Also reported: Seats (1), Steering (1), Transmission and drivetrain (1).
Example complaints
Brakes: “I was already 90% in parking line which is handicap's. About to stop right front of handicap sign, suddenly vehicle start moving forward while my foot was in brake so I push little hard to complete stop but vehicle suddenly accelerate forward smashing into the building glass entry wall and door. I am so certain that my foot was in brake. I want to know that is there any way someone call or visit where body shop to inspect the vehicle so I can ask manufacture to replace my vehicle.”
NHTSA complaint #11353649, filed 2020-09Suspension: “I took the car to the service 3 times in 4 months. There are many problems with the car. The first problem was that the left rear shock was leaking which made a squeaking noise when driving. There was also an odor problem with the car that was coming from the ventilations. These two problems were fixed. I took the car another time. There was another problem with the eco start/stop function and a problem with the car trunk only closing halfway. The eco start/stop function was fixed but they said that they didn't detect a problem with the trunk. …”
NHTSA complaint #11299367, filed 2020-01, 8,000 milesEngine: “The contact owned a 2018 Mercedes Benz GLS450. The contact stated that after turning the ignition switch off, the driver suddenly discovered flames were coming from the engine compartment. The fire department was called to the scene and extinguished the flames. During the incident, the vehicle was destroyed and later towed away. A fire report was taken at the scene. The cause of the failure was not determined. The manufacturer and local dealer were notified of the failure. The VIN was not available. The failure mileage was 15,000.”
NHTSA complaint #11436804, filed 2021-10, 15,000 milesMileage when problems were reported
100% of the 7 complaints with a mileage were filed for vehicles with under 50,000 miles; the middle half falls between 8,000 and 8,000 miles.
Complaints by year filed
Fewer than 15 complaints, too few for a reliable trend.
Fuel economy and running cost
EPA ratings for each 2018 Mercedes-Benz GLS 450 version. Annual fuel cost is the EPA's estimate at its current fuel prices for 15,000 miles a year (55% city driving).
| Version | Engine | Transmission | City | Hwy | Comb. | Fuel / yr |
|---|---|---|---|---|---|---|
| GLS450 4matic 4WD | 3.0L 6-cyl | 9-speed automatic | 17 | 22 | 19 | $4,350 |
Source: U.S. EPA and Department of Energy, fueleconomy.gov. Ratings are for comparing vehicles; real-world mileage varies with driving and conditions.
Recalls and investigations
- 22V365000May 20, 2022Electrical system › SoftwareCovers: Mercedes-Benz GLS 450 2017–2021, C300 2017–2021, GLA 250 2017–2021 +48 more
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2017-2022 CLA-Class, GLA-Class, GLE-Class, GLS-Class, SLC-Class, A-Class, AMG GT-Class, C-Class, E-Class, S-Class, SL-Class, GLC-Class, CLS-Class, GLB-Class, and G-Class vehicles. Please refer to MBUSA's…
- 21V058000Feb 5, 2021Electrical system › SoftwareCovers: Mercedes-Benz GLS 450 2017–2021, C300 2016–2021, CLA250 2016–2021 +65 more
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2016 - 2021 CLA-Class, GLA-Class, GLE-Class, GLS-Class, SLC-Class, A-Class, GT-Class, C-Class, E-Class, S-Class, CLS-Class, SL-Class, B-Class, GLB-Class, GLC-Class, and G-Class vehicles. Please refer to the…
- 18V539000Aug 16, 2018Service brakes, hydraulicCovers: Mercedes-Benz GLS 450 2018, GLS 550 2018, GLE 350 2018 +4 more
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2018 Mercedes-Benz GLE350 4Matic, GLE350, GLS450 4Matic, GLS550 4matic, GLE43 AMG 4Matic, GLE63 AMG 4Matic, GLE63S AMG 4Matic, and GLS63 AMG 4Matic vehicles. The rear brake caliper pistons on these vehicles…
Recall details for the 2018 Mercedes-Benz GLS 450 → · Check a VIN at nhtsa.gov/recalls
Technical service bulletins
TSBs are manufacturer notes to dealers about known repair procedures. They are not recalls and do not by themselves mean a vehicle has a fault. 91 on record; the latest 10 are shown.
- 11038187Sep 26, 2026Transmission and drivetrain. Complaint Customer complaints relating to automatic transmission 725.0 (NAG3 Classic /9G‑TRONIC automatic transmission) and 725.1 (NAG3 facelift/9G‑TRONIC automatic transmission facelift) For…
- 11038186Sep 22, 2026Brakes. Complaint Repeat workshop visit for vehicle vibration while braking from 60MPH. NOTE: Although the symptom is similar to a tire or wheel vibration, it is usually readily noticeable that it is…
- 11038217Sep 14, 2026Body and structure. Complaint Clanking noise from the area of the speakers in the doors. Cause Under analysis. Remedy To narrow down the cause, first of all remove the door trim. • If the noise continues to occur even…
- 11037987Sep 14, 2026Transmission and drivetrain. Complaint Only vehicles with a variable transfer case are affected. This can be identified through control unit N45 or N15/7 in the quick test. When accelerating with light load, vibrations or…
- 11037616Sep 4, 2026Transmission and drivetrain. Complaint Customer complaints relating to automatic transmission 725.0 (NAG3 Classic / 9G‑TRONIC automatic transmission) and 725.1 (NAG3 facelift/9G‑TRONIC automatic transmission facelift) For…
- 11037228Aug 28, 2026Steering. Complaint During part of the steering movement, it feels heavier or more difficult to steer in the same spot every time. OR Rattling, humming, dry sliding/gravel noise from the electric steering…
- 11036999Aug 15, 2026Fuel system. Dear Mercedes-Benz Owner: In our continuing efforts to ensure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA is extending the…
- 11036190Aug 6, 2026Electrical system. Complaint A popup is seen on the HU with the message "data connection temporarily not available". Potentially affected functionalities in NTG4.5, NTG5 1.Weather 2.Local Search 3.IP Radio 4.Send2Car…
- 11036101Aug 6, 2026Body and structure. Complaint Clanking noise from the area of the speakers in the doors. Cause Under analysis. Remedy To narrow down the cause, first of all remove the door trim. • If the noise continues to occur even…
- 11036077Aug 5, 2026Transmission and drivetrain. Complaint This document is intended as a pre-case diagnostic reference for transmission related concerns. It will also ensure that if a case is necessary, all supporting documentation is available…
Other model years of the Mercedes-Benz GLS 450
| Year | Complaints | Median mi | Recalls | Crash ★ | MPG | Score (50 = typical) | Trend |
|---|---|---|---|---|---|---|---|
| 2021 | 31 | 11,000 | 12 | — | 21 | 54 · Typical | Rising |
| 2020 | 36 | 4,200 | 22 | — | 21 | 50 · Typical | Rising |
| 2019 | 24 | 31,415 | 3 | — | 18 | — | Rising |
| 2018 | 14 | 8,000 | 3 | — | 19 | — | Not enough data |
| 2017 | 35 | 13,000 | 8 | — | 19 | 43 · Typical | Rising |
All Mercedes-Benz GLS 450 model years · Best and worst years by complaints
Frequently asked questions
How many NHTSA complaints does the 2018 Mercedes-Benz GLS 450 have?
NHTSA recorded 14 consumer complaints for the 2018 Mercedes-Benz GLS 450 as of Oct 27, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.
What part of the 2018 Mercedes-Benz GLS 450 is reported most often?
Brakes is named most often, in 3 complaints (21% of the total), followed by suspension with 3.
Has the 2018 Mercedes-Benz GLS 450 been recalled?
NHTSA lists 3 recall campaigns for this model year. To check a specific vehicle, enter its VIN at nhtsa.gov/recalls.
What gas mileage does the 2018 Mercedes-Benz GLS 450 get?
The EPA rates the 2018 Mercedes-Benz GLS 450 (GLS450 4matic, 3.0L 6-cyl) at 19 mpg combined, 17 city and 22 highway, with an estimated annual fuel cost of $4,350 at 15,000 miles a year. Other engine and drive versions are rated differently.
At what mileage are problems with the 2018 Mercedes-Benz GLS 450 reported?
Among the 7 complaints that include a mileage, the median is 8,000 miles and the middle half falls between 8,000 and 8,000 miles; 100% were filed for vehicles with under 50,000 miles.
About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 27, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate. Fuel economy is from the EPA and DOE (fueleconomy.gov).
Complaint counts come from NHTSA’s public complaint database; we count each complaint once. The source records for this vehicle are on nhtsa.gov. Scores and trends are our own summaries of that data, described in the methodology. This page is not legal, safety or repair advice: for a specific vehicle, check its VIN at nhtsa.gov/recalls and ask a qualified mechanic. See an error? Tell us.