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Mercedes-Benz GLS 450Model year report

2021 Mercedes-Benz GLS 450 Problems

Compared with other Mercedes-Benz GLS 450 years

Typical for this model

57/100 1.2× a typical year · 50 = typical

Nearby years with fewer complaints than typical and no open NHTSA investigation: 2019

Based only on NHTSA complaints, recalls and investigations. Not adjusted for how many vehicles were sold, and not a reliability rating. How this is calculated

Complaints
31filed with NHTSA
Median mileage
11,000miles, 3 complaints with mileage
Recalls
12campaigns on record
Trend
RisingComplaints filed in the last 3 full calendar years are at least 25% higher than in the 3 years before.
NHTSA crash rating
—no overall rating published
EPA fuel economy
21 mpgcombined, 3.0L 6-cyl · hybrid 4WD · 20 city / 24 hwy

Sources: NHTSA records for the 2021 Mercedes-Benz GLS 450 (complaints, recalls, investigations), EPA fuel economy. Report an error

NHTSA recorded 31 consumer complaints for the 2021 Mercedes-Benz GLS 450. The part named most often is electrical system, with 14 complaints (45% of the total), followed by other or unknown (8) and engine (3). 3 of the complaints include a mileage, and 100% of those were filed for vehicles with under 50,000 miles; the median is 11,000 miles. Of all complaints, 1 involved a crash, 2 a fire, 1 an injury, according to the filers. NHTSA lists 12 recall campaigns and 272 technical service bulletins for this model year. Electrical system complaints overlap with 4 recall campaigns covering the interior/under dash and 134 technical service bulletins filed under the same part. Other or unknown complaints overlap with 9 technical service bulletins filed under the same part. Compared with the other 3 Mercedes-Benz GLS 450 model years that have at least 25 complaints and are old enough to compare, this one scores 57 out of 100, where 50 is a typical year for the model (typical for this model). The comparison allows for the era and for how long each year has had to collect complaints, but not for how many vehicles were sold.

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.

Also reported: Tires (1), Transmission and drivetrain (1), Vehicle speed control (1), Visibility (wipers, defrost, mirrors) (1), Wheels (1).

Example complaints

Electrical system: “We accepted delivery of our brand new vehicle in May 2021 from the dealer. In July 2021, the vehicle became completely disabled due to failure of the 48 volt battery. In October 2021, the dealer replaced 48 volt battery failed again causing the vehicle to become completely disabled. In December 2023, our 3rd replacement 48 volt battery failed. Each time the vehicle is out of service for a week or longer. The dealer is not providing any information about what may be causing the failures. Vehicle has become completely unreliable and dangerous. …”

NHTSA complaint #11561635, filed 2023-12

Other or unknown: “The car would not start and could not be jumped. I'm told it's the 48V battery has to be replaced. I have seen on the internet numerous people have the same problem and that a large batch of these 48V batteries are the problem. Error message displays stop the vehicle and more details advises battery is malfunctioning and do not continue driving.”

NHTSA complaint #11442482, filed 2021-12

Engine: “On four occasions my car has stalled while in traffic very early in my ownership and then it happened again today with my family in the car and nearly caused an accident. The entire dash lights up with every warning when it happens. Sometimes the check engine light comes on after I shut the car off and restart it. My Mercedes dealer has had it in multiple times for this reason. The last time it was in for this (May of 2022) they reprogrammed the entire car. It happening again today has really made me lose a lot of faith in the vehicle, especially since we purchased it for the safety factors. …”

NHTSA complaint #11500946, filed 2023-01

Lane departure: “The contact owns a 2021 Mercedes-Benz GLS450. The contact stated that while driving at various speeds, the Lane Departure safety feature independently activated as he attempted to avoid either a person or an object in the lane of traffic. As the contact attempted to steer around the pedestrian or object in the lane of traffic, the safety feature independently jerked the vehicle back into the lane and into the pedestrian or object he attempted to avoid. …”

NHTSA complaint #11455544, filed 2022-03

Mileage when problems were reported

100% of the 3 complaints with a mileage were filed for vehicles with under 50,000 miles; the middle half falls between 3,000 and 25,000 miles.

33%0–1033%10–2533%25–500%50–750%75–1000%100–1500%150+
Share of complaints by mileage when the problem was reported, in thousands of miles (3 complaints with mileage). Red bars: under 50,000 miles. Bucket widths differ. Median: 11,000 miles.

Complaints by year filed

Trend: rising. Complaints filed in the last 3 full calendar years are at least 25% higher than in the 3 years before.

20212022102023202420252026
Complaints by year the complaint was filed with NHTSA. Red bars: the last 3 full calendar years used for the trend. The current year (2026) is partial.

Fuel economy and running cost

EPA ratings for each 2021 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).

VersionEngineTransmissionCityHwyComb.Fuel / yr
GLS450 4matic 4WD3.0L 6-cyl · hybrid9-speed automatic202421$3,900

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

See all 12 recalls for the 2021 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. 272 on record; the latest 10 are shown.

See all 272 bulletins →

Other model years of the Mercedes-Benz GLS 450

YearComplaintsMedian miRecallsCrash ★MPGScore (50 = typical)Trend
20213111,00012—2157 · TypicalRising
2020364,20022—2153 · TypicalRising
20192531,4153—180 · FewerRising
2018148,0003—19—Not enough data
20173513,0008—1946 · TypicalRising

All Mercedes-Benz GLS 450 model years · Best and worst years by complaints

Frequently asked questions

How many NHTSA complaints does the 2021 Mercedes-Benz GLS 450 have?

NHTSA recorded 31 consumer complaints for the 2021 Mercedes-Benz GLS 450 as of Oct 31, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.

What part of the 2021 Mercedes-Benz GLS 450 is reported most often?

Electrical system is named most often, in 14 complaints (45% of the total), followed by other or unknown with 8.

Has the 2021 Mercedes-Benz GLS 450 been recalled?

NHTSA lists 12 recall campaigns for this model year. To check a specific vehicle, enter its VIN at nhtsa.gov/recalls.

What gas mileage does the 2021 Mercedes-Benz GLS 450 get?

The EPA rates the 2021 Mercedes-Benz GLS 450 (GLS450 4matic, 3.0L 6-cyl · hybrid) at 21 mpg combined, 20 city and 24 highway, with an estimated annual fuel cost of $3,900 at 15,000 miles a year. Other engine and drive versions are rated differently.

At what mileage are problems with the 2021 Mercedes-Benz GLS 450 reported?

Among the 3 complaints that include a mileage, the median is 11,000 miles and the middle half falls between 3,000 and 25,000 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 31, 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.