YearToAvoid

2018 Mercedes-Benz Gls450 Problems, Recalls & Reliability

Verdict

Best

Complaint Index

20/100

#5 most-complained of 6 Gls450 years

Based on NHTSA complaints per model-year, not a reliability rating. Methodology

The 2018 Mercedes-Benz Gls450 has a complaint index of 20, ranks 5th worst out of 6 model years, and carries a "Best" verdict for the model. It has 14 NHTSA complaints, 3 recalls, and 3 reported fires.

Complaints
14
Recalls
3
Crashes / fires
1 / 3
Injuries / deaths
0 / 0
NHTSA overall rating
Not rated
EPA combined MPG
19
17 city / 22 hwy

Top 2018 Mercedes-Benz Gls450 problems

NHTSA owner complaints by component group. Groups with 15+ complaints have their own page.

  1. Brakes4 (29%)
  2. Electrical System3 (21%)
  3. Structure & Body3 (21%)
  4. Suspension, Wheels & Tires3 (21%)
  5. Engine2 (14%)
  6. Collision Avoidance & Cameras1 (7%)
  7. Fuel System1 (7%)
  8. Other1 (7%)
  9. Steering1 (7%)
  10. Transmission & Powertrain1 (7%)

What owners report

  • Owners report sudden loss of power at highway speed with warning lights illuminating and brakes failing to stop the vehicle.
  • Some describe the vehicle unexpectedly accelerating forward while the brake pedal was depressed, leading to a crash into a building.
  • Owners report engine compartment fires starting shortly after the ignition was turned off.
  • Drivers describe the steering pilot / driver assistance feature behaving erratically and nearly causing a crash.
  • Some report the panoramic sunroof spontaneously shattering while the vehicle was stationary.
  • Owners describe the air suspension system failing repeatedly, with the compressor pushing to compensate before failing again.
2018 Mercedes-Benz Gls450 complaints: complaints filed per month3May 2018Nov 2018Sep 2020Oct 2021Dec 2022Aug 2025
20 complaints filed with NHTSA from May 2018 to Dec 2025; peak Jan 2020 (3).

2018 Mercedes-Benz Gls450 recalls

3 NHTSA recall campaigns list this model year.

  1. NHTSA 22V365000May 20, 2022Electrical System242,722 vehiclesOver-the-air fix

    Electrical system:software

    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 recall report for specific vehicle model details. An error in the communication module's SIM card software can cause a mobile network connection failure, disabling the emergency call (eCall) system.

    Risk: A disabled eCall system would prevent a vehicle occupant from contacting the emergency services call center in an emergency, potentially delaying emergency responders and increasing the risk of injury.

    Remedy: The communication module software will be updated through an Over-the-Air (OTA) update or by a dealer, free of charge. Owner notification letters were mailed July 8, 2022. Owner notification letters will be mailed in phases, on July 8, 2022, May 17, 2024, July 29, 2024, and September 27, 2024. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's numbers are for this recall is 2022060005 and 2023110006.

  2. NHTSA 21V058000Feb 5, 2021Other1,292,258 vehiclesOver-the-air fix

    Communication: auto crash notification

    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 Part 573 report for specific vehicle model details. The software design of the communication module may fail to communicate the correct vehicle location for the emergency call system (eCall) in the event of a crash.

    Risk: Failure of the eCall system may result in emergency responders being dispatched to the wrong location, increasing the risk of injury following a crash.

    Remedy: MBUSA will notify owners, and the communication module software will be updated by a dealer, or through an over-the-air (OTA) update, free of charge. The recall began March 12, 2021. Owners may contact MBUSA customer service at 1-877-762-8267. MBUSA's number for this recall is 2021020025.

  3. NHTSA 18V539000Aug 16, 2018Brakes9,044 vehicles

    Service brakes, hydraulic

    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 may not have been correctly coated, causing gas to become temporarily released into the rear brake hydraulic circuit, reducing braking performance.

    Risk: Reduced braking performance can increase the risk of a crash.

    Remedy: MBUSA will notify owners, and dealers will bleed the rear axle brake system, free of charge. The recall began September 14, 2018. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's number for this recall is 2018080013.

2018 Mercedes-Benz Gls450 fuel economy and fuel cost

City
17 MPG
Highway
22 MPG
Combined
19 MPG
Annual fuel cost (EPA)
$4,200
15,000 mi/yr
Fuel
Premium
Current regular gas
$4.32/gal
national avg.

EPA figures; median across configurations of this model year. Estimate your own cost with the fuel cost calculator.

2018 compared with other Gls450 years

Complaint Index by model year (0 = fewest issues, 100 = most)0255075100201620172018201920202021
Complaint Index: 0 = fewest issues, 100 = most, relative to other years of this model. Avoid Caution Good Best
YearVerdictIndexComplaintsRecallsMPG
2016No verdict001—
2017Caution6035819
2018Best2014319
2019Good4024318
2020Avoid100362221

All Mercedes-Benz Gls450 years: best and worst →

Frequently asked questions

Is the 2018 Mercedes-Benz Gls450 reliable based on NHTSA data?
The 2018 model year has a complaint index of 20, the lowest among the 6 model years with data, and carries a "Best" verdict relative to other Gls450 years.
What are the most common problems on the 2018 Gls450?
NHTSA complaints for this year are led by Brakes at 29% share, followed by Electrical System, Structure & Body, and Suspension, Wheels & Tires, each at 21%.
Does the 2018 Mercedes-Benz Gls450 have any recalls?
NHTSA lists 3 recalls for the 2018 Gls450, covering the Electrical System, an "Other" component, and Brakes, none marked do-not-drive.
How does the 2018 Gls450 compare to other model years?
The 2018 model ranks 5th worst out of 6 years by complaint index (20), well below 2020 and 2021, which have complaint indexes of 100 and 80 and "Avoid" verdicts.
What is the fuel economy of the 2018 Mercedes-Benz Gls450?
EPA rates the 2018 Gls450 at 19 mpg combined (17 city / 22 highway), with an estimated annual fuel cost of $4,200.

Sources: NHTSA Office of Defects Investigation complaint and recall databases; U.S. EPA fuel economy data; NHTSA 5-Star Safety Ratings. Complaints are unverified owner reports.

Data updated Sep 24, 2026. Read the methodology and data sources. The Complaint Index is based on NHTSA owner complaints and recalls; it is not a reliability rating.