Head-to-head reliability
Mercedes BENZ A Class vs Mercedes BENZ S Class
How the Mercedes BENZ A Class and Mercedes BENZ S Class compare on NHTSA complaints, recalls and crash reports — and which is the lower-risk used buy.
Based on NHTSA owner-complaint & recall records
Mercedes BENZ A Class vs Mercedes BENZ S Class: The A-Class has 77 complaints over 4 years (19.3/yr) with sudden shutdowns and limp mode, while the S-Class has 171 over 10 years (17.1/yr) with electrical fires and brake issues. Both have no recalls, but the S-Class has 1 death. Source: NHTSA owner complaints.
The picture
Is the Mercedes BENZ A Class or Mercedes BENZ S Class more reliable?
A plain-English read on what the NHTSA record says about living with each vehicle.
Mercedes BENZ A Class
The Mercedes-Benz A-Class, a compact luxury sedan, shows a concerning reliability profile with 77 complaints over four years, averaging nearly 20 per year. Owners frequently report sudden engine shutdowns, transmission stalls, and limp mode incidents, often occurring at highway speeds or intersections, which can be alarming. Electrical system issues are the most common, but engine and fuel system problems also feature prominently, suggesting a pattern of drivability and safety-related failures.
Mercedes BENZ S Class
The Mercedes-Benz S-Class, a full-size luxury flagship, has 171 complaints over ten years, averaging about 17 per year, slightly lower than the A-Class. The complaints highlight issues with electrical systems, forward collision avoidance, engine misfires, and service brakes. Owners describe harsh shifting, unexpected deceleration with adaptive cruise control, and even a small fire under the driver's seat, indicating a mix of convenience and safety-critical problems.
The numbers
Side-by-side NHTSA record
Lower is better in every category. The highlighted cell is the stronger result.
| Category | Mercedes BENZ A Class | Mercedes BENZ S Class |
|---|---|---|
| Total complaintsAll model years combined | 77 Better | 171 |
| Safety recallsFederal recall campaigns | 0 | 0 |
| Crash reportsCrash-related complaints | 3 Better | 6 |
| Complaints per yearAveraged across model years | 19.3 | 17.1 Better |
| Reported injuriesTied to owner complaints | 3 Better | 7 |
| Reported deathsTied to owner complaints | 0 Better | 1 |
Source: NHTSA owner complaints & recall records.
What actually goes wrong
The problems owners report
The most-complained-about systems on each vehicle — what fails, and what owners say in their own words.
Mercedes BENZ A Class
- 01ELECTRICAL SYSTEM24
- 02UNKNOWN OR OTHER22
- 03ENGINE19
- 04FUEL/PROPULSION SYSTEM9
- 05BACK OVER PREVENTION9
Owners report the car completely shutting down while driving, sometimes mid-intersection, with no warning. This can be dangerous and leaves the driver without power steering or brakes.
Engine issues include sudden loss of power and entering 'limp mode,' limiting speed to under 10 mph, which is hazardous when merging onto highways.
The car may unexpectedly shut off at red lights and shift into neutral, requiring a restart. This can cause confusion and potential rear-end collisions.
“While driving my lease vehicle on two separate days, it completely shut down while in motion with no prior warning. The first incident occurred while crossing a MAX train intersection in downtown Portland. The engine stopped mid intersection, emitted a strong…”
“August 2024 the dealership had my vehicle for over a month for major engine repairs after the motor mount snapped on the freeway and since then I only drove 3661 miles and I’m now convinced that they miss diagnosed and missed something It never drove the same…”
Mercedes BENZ S Class
- 01ELECTRICAL SYSTEM31
- 02FORWARD COLLISION AVOIDANCE30
- 03ENGINE23
- 04SERVICE BRAKES23
- 05UNKNOWN OR OTHER22
Owners report harsh gear shifts and a burning odor with smoke from under the driver's seat, indicating potential electrical fires. This is a serious safety risk.
The system can cause the vehicle to decelerate without driver input, especially with adaptive cruise control, and may misread speed limit signs, leading to sudden speed changes.
Engine misfires on acceleration cause power loss and shaking, which can be dangerous when trying to pass other vehicles.
Braking issues include the car pulling to one side and unexpected seat belt tightening, suggesting potential brake system or sensor malfunctions.
“I am reporting a recurring transmission/drivability issue with my 2024 Mercedes-Benz S580. The vehicle has been experiencing a harsh, abnormal shift between approximately 3rd and 4th gear at around 25–35 mph during normal acceleration. The shift feels like a…”
“The contact owns a 2019 Mercedes-Benz S560. The contact stated that while parking their vehicle, a burning-leather odor entered the cabin, and they noticed smoke in the cabin. The contact noticed a small fire beneath the driver's seat. The fire was extinguish…”
Buyer analysis
Mercedes BENZ A Class or Mercedes BENZ S Class: which should you buy?
The A-Class has a slightly higher complaint rate per year (19.3 vs 17.1), but both have significant issues. The A-Class's sudden shutdowns and limp mode are more immediately dangerous, while the S-Class's electrical fire and brake issues are also critical. Neither is clearly safer, but the A-Class's higher rate and severity of drivability failures may be more concerning for daily driving.
Key differences
- The A-Class has more complaints per year (19.3) than the S-Class (17.1), but the S-Class has more total complaints over a longer period.
- A-Class owners report sudden engine shutdowns and limp mode, while S-Class owners report harsh shifting and forward collision avoidance glitches.
- The S-Class has a report of a small fire under the driver's seat, a severe safety issue not seen in the A-Class.
- Both have no recalls, but the A-Class has 3 crashes and 3 injuries, while the S-Class has 6 crashes, 7 injuries, and 1 death.
- Check for any history of engine stalling or transmission issues, especially at low speeds or stops.
- Inspect the electrical system for any signs of intermittent failures, such as dashboard warnings or unexpected shutdowns.
- Look for signs of electrical problems, such as burning smells or smoke from under the seats.
- Test the adaptive cruise control and forward collision avoidance systems to ensure they don't cause unexpected deceleration.
Before you buy
- Obtain a full service history and check for any open recalls or technical service bulletins.
- Have a trusted mechanic perform a pre-purchase inspection, focusing on engine, transmission, and electrical systems.
- Test drive at various speeds, including highway merging, to check for limp mode or misfires.
- For the S-Class, specifically test the adaptive cruise control and brakes in a safe area.
- Consider purchasing an extended warranty to cover potential costly repairs.
Year by year
Which model years to avoid
Complaints per model year for both vehicles — lower is better. The spikes are the years to scrutinize.
| Year | Mercedes BENZ A Class | Mercedes BENZ S Class |
|---|---|---|
| 2022 | 3 | 46 |
| 2021 | 9 | 33 |
| 2020 | 21 | 7 |
| 2019 | 44 | 16 |
Check the actual car
Comparing models is smart. Checking the VIN is essential.
Brand averages tell you the trend. A VIN check tells you what's wrong with the specific Mercedes BENZ A Class or Mercedes BENZ S Class in front of you — accident history, open recalls and title records.
Go deeper
Full reliability reports
- Comparison
- Mercedes BENZ A Class vs Mercedes BENZ S Class
- Mercedes BENZ A Class total complaints
- 77
- Mercedes BENZ S Class total complaints
- 171
- Mercedes BENZ A Class total recalls
- 0
- Mercedes BENZ S Class total recalls
- 0
- Mercedes BENZ A Class avg complaints/year
- 19.3
- Mercedes BENZ S Class avg complaints/year
- 17.1
- More reliable overall
- Mercedes BENZ S Class
- Mercedes BENZ A Class top complaint area
- ELECTRICAL SYSTEM
- Mercedes BENZ S Class top complaint area
- ELECTRICAL SYSTEM