Is the 2021 Mercedes-Benz GLS450 reliable?

The 2021 Mercedes-Benz GLS450 has 41 complaints filed with NHTSA (1.0x the segment average). Our reliability verdict: average. Most common issue: ELECTRICAL problems.

What are common problems with the 2021 Mercedes-Benz GLS450?

Top problems: ELECTRICAL (14 complaints, avg repair $500); OTHER (8 complaints, avg repair $500); DRIVER ASSIST/CAMERAS (4 complaints, avg repair $500). Issues typically appear around 50K miles.

Are there any recalls on the 2021 Mercedes-Benz GLS450?

Yes, there are 12 recall(s): BACK OVER PREVENTION: SENSING SYSTEM: CAMERA, ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL, VISIBILITY:GLASS, SIDE/REAR, ELECTRICAL SYSTEM:SOFTWARE, ELECTRICAL SYSTEM:WIRING:INTERIOR/UNDER DASH, ELECTRICAL SYSTEM:SOFTWARE, STRUCTURE:BODY, SEATS:MID/REAR ASSEMBLY, VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM, FUEL SYSTEM, GASOLINE:DELIVERY:FUEL PUMP, POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE:SOFTWARE, ELECTRICAL SYSTEM:WIRING. Contact any Mercedes-Benz dealer to verify if recalls have been completed on your specific vehicle.

How much does it cost to fuel a 2021 Mercedes-Benz GLS450?

The 2021 Mercedes-Benz GLS450 gets 21 MPG combined. At current US average gas prices, driving 12,000 miles per year costs roughly $2286. See the interactive fuel cost calculator on this page for state-specific pricing.

How much does it cost to insure a 2021 Mercedes-Benz GLS450?

Estimated US average full-coverage insurance for the 2021 Mercedes-Benz GLS450 is approximately $2,373/year (suv-luxury class). Actual quotes vary heavily by state, driver age, driving record, and credit — see the interactive insurance estimator on this page for state-specific pricing.

2021 Mercedes-Benz GLS450

Problems, Recalls & Reliability Report

Average

Quick Summary

The 2021 Mercedes-Benz GLS450 has 41 owner complaints filed with NHTSA — that's 1.0x the segment average of 41. The most common issue is electrical problems (34% of all complaints), specifically: 2021 gls 450 vin # 4jgff5ke9ma404568 purch: nov 26, 2022 uag fairfield auto group cm, llc,dba mercedes benz of fairfield odometer date of purchase 10,084 odometer currently *13,700 (onboard notification) timeline: total vehicle system fails while driving on highway lost engine, steering, power su. There are 12 recalls issued for this model year. ⚠️ 4 fire reports filed.

4 fire reports 1 crash report 1 injury

Total Complaints

Recalls Issued

—/5

Safety Stars

1.0x

vs Segment Avg

Known Problems(top 5 of 8)

ELECTRICAL

14 complaints

34%

• 2021 GLS 450 VIN # 4JGFF5KE9MA404568 Purch: Nov 26, 2022 UAG Fairfield Auto Group CM, LLC,DBA MERCEDES BENZ OF FAIRFIELD Odometer Date of Purchase 10,084 Odometer Currently *13,700 (onboard notification) TIMELINE: Total vehicle system fails while driving on highway lost engine, steering, power su
• 2021 MERCEDES BENZ GLS450. CONSUMER WRITES IN REGARDS TO48-VOLT BATTERY SYSTEM FAILURE. THE CONSUMER STATED THE HAS FAILED TWICE, A YEAR APART. THE DASHBOARD DISPLAYED "48-VOLT BATTERY FAILURE" AND "CHECK ENGINE". THE VEHICLE WOULD FAIL WHILE BEING DRIVEN. THE VEHICLE WAS RESTARTED AND OPERATED AS
• Vehicle would not start on 3 separate occasions. The instrument panel indicated it was the 48v battery. Had it towed to Mercedes dealership to have 48v battery replaced.

Typical onset: 50K miles Est. repair: $500🔥 2 fire reports

“2021 GLS 450 VIN # 4JGFF5KE9MA404568 Purch: Nov 26, 2022 UAG Fairfield Auto Group CM, LLC,DBA MERCEDES BENZ OF FAIRFIELD Odometer Date of Purchase 10,084 Odometer Currently *13,700 (onboard notification) TIMELINE: Total vehicle system fails while driving on highway lost engine, steering, power su”

— NHTSA complaint filing

Recalls (12)

BACK OVER PREVENTION: SENSING SYSTEM: CAMERA14/05/2021

Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2019-2021 CLA-Class, GLE/GLS-Class, A-Class, E-Class, E-Class Coupe and Convertible, GLA/GLB-Class, GLC-Class, CLS-Class, and AMG GT-Class 4-door Coupe vehicles. Please refer to MBUSA's recall report for specific vehicle model details. The MBUX multimedia system software may cause the display to remain black, or reboot after startup. This could result in the rearview camera image not displaying properly. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) number 111, "Rear Visibility."

Risk: A backup camera that displays a blank image reduces the driver's rear view, increasing the risk of a crash or injury.

Fix: The multimedia system software will be updated by a dealer, or through an over-the-air (OTA) update, free of charge. Owner notification letters were mailed beginning June 28, 2021. Owners may contact MBUSA customer service at 1-800-367-6373. MBUSA's number for this recall is 2021050012.

Fuel Cost Calculator for 2021 Mercedes-Benz GLS450

Live EIA prices

Annual miles driven: 12,000

Your state (affects local gasoline price)

Per year

$2,286

Per month

$191

Per mile

19.1¢

MPG

City driving (worst-case MPG)

$2,401/yr

Highway driving (best-case MPG)

$2,001/yr

Based on EPA fuel-economy ratings and EIA weekly retail prices (2026-07-20). Real-world cost varies with driving style, trim/engine, terrain, and traffic.

5-Year Gas Price History

EIA weekly retail data · 2021 → today

Show:

Current

$4.00

5-year low

$2.78

5-year high

$5.01

Since 2021

+27%

Source: US Energy Information Administration weekly retail gasoline prices.

Estimated Insurance Cost for 2021 Mercedes-Benz GLS450

Estimate only, not a quote. Modeled from NAIC + HLDI averages for a hypothetical 35-year-old driver with clean record + full coverage. Your actual quote depends heavily on your age, driving history, credit, ZIP code, and insurer.

Your state (affects local premium average)

Full coverage / year

$2,373

Full coverage / month

$198

Liability only / year

$732

vs US avg

+42%

How this estimate is calculated

US base full-coverage premium$1674

× state (US)1.00x

× vehicle class (suv-luxury)1.35x

× theft risk1.00x

× safety rating1.00x

× vehicle age1.05x

= Full coverage estimate$2373

Coverage assumed: 100/300/100 liability + comprehensive/collision, $500 deductibles. Data sources: NAIC 2024 + HLDI loss studies.

Maintenance & Warranty

Recommended Mercedes-Benz GLS450 Service Intervals

Oil change

10K mi / 12 mo

Tire rotation

10K mi

Brake fluid

24 months

Transmission fluid

40K mi

Engine coolant

150K mi

Spark plugs

60K mi

Cabin air filter

20K mi

Engine air filter

40K mi

Differential (AWD/4WD)

40K mi

Service A / Service B alternating schedule. Requires MB-approved oil (229.5 spec typically).

"Severe service" conditions (heavy towing, extreme temps, city stop-and-go) typically halve these intervals. Always consult your vehicle's owner's manual for the authoritative schedule.

Mercedes-Benz New-Vehicle Warranty Coverage

Bumper-to-bumper (basic)

4 yr / 50K mi

Powertrain

4 yr / 50K mi

Hybrid/EV battery

10 yr / 155K mi

Corrosion (rust perforation)

4 yr / 50K mi

Roadside assistance

4 yr / unlimited mi

EQ EV battery warranty is 10 years/155,000 miles

These are the terms for a new Mercedes-Benz. If you're buying a used 2021 GLS450, remaining coverage is usually pro-rated from the vehicle's original in-service date. Not all coverage transfers between owners — check with a Mercedes-Benz dealer for VIN-specific remaining warranty.

Estimated Repair Costs

ELECTRICAL(~50K mi)

$500

OTHER(~50K mi)

$500

DRIVER ASSIST/CAMERAS(~50K mi)

$500

SPEED CONTROL(~50K mi)

$500

ENGINE(~50K mi)

$500

Estimates based on average reported repair costs. Actual costs vary by location, shop, and severity.

🔍 Pre-Purchase Inspection Checklist

Based on 41 owner complaints for this specific year, here's what to check or ask about:

☐
ELECTRICAL: 2021 GLS 450 VIN # 4JGFF5KE9MA404568 Purch: Nov 26, 2022 UAG Fairfield Auto Group CM, LLC,DBA MERCEDES BENZ OF FAIRFIELD Odometer Date of Purchase 10,084 Odometer Currently *13,700 (onboard notification) TIMELINE: Total vehicle system fails while driving on highway lost engine, steering, power su
Typically appears around 50K miles. Repair cost ~$500
☐
OTHER: 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
Typically appears around 50K miles. Repair cost ~$500
☐
DRIVER ASSIST/CAMERAS: 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 ob
Typically appears around 50K miles. Repair cost ~$500
☐
SPEED CONTROL: The contact owns a 2021 Mercedes Benz GLS450. The contact stated while driving 75 mph with the cruise control engaged, the vehicle decelerated to 45 mph than to 15 mph. On another occasion, while driving 80 mph, the vehicle independently decelerated to 45 mph. There was no warning light illuminated.
Typically appears around 50K miles. Repair cost ~$500
☐
RECALLS: Verify all 12 recalls have been completed — free at any Mercedes-Benz dealer
☐
General: Get a pre-purchase inspection from an independent mechanic ($100-$200)

Mercedes-Benz GLS450 — Year Comparison

How does 2021 compare to other years? Fewer complaints = more reliable.

2021

41Average

2019

7Excellent Reliability

2017

51Below Average

Full years-to-avoid analysis →

NHTSA Safety Rating

No NHTSA safety rating available

At a Glance

Complaints: 41
Recalls: 12
Fire reports: 4
Crash reports: 1
Injury reports: 1
Segment avg: 41

Check a Specific VIN

See recalls for YOUR 2021 Mercedes-Benz GLS450

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