What US owners actually complain about

Background

This findings set addresses a basic consumer question: what US owners actually complain about most. The pattern is concentrated in a relatively small group of vehicle systems, with engine-related complaints leading the list.

The largest single category is ENGINE, with 72,435 complaints, representing 21.4% of the total recorded in this component breakdown. That is followed by ELECTRICAL SYSTEM at 58,223 and 17.2%, and POWER TRAIN at 50,180 and 14.8%.

For readers asking about the most common car problems, the findings point first to core mechanical and electrical systems rather than cosmetic or convenience issues. The highest-volume complaint areas are the systems that determine whether a vehicle starts, runs, moves, and responds as expected.

The biggest complaint categories

The complaint distribution shows a clear ranking across major systems.

Component	Complaints	Share
ENGINE	72,435	21.4%
ELECTRICAL SYSTEM	58,223	17.2%
POWER TRAIN	50,180	14.8%
UNKNOWN OR OTHER	47,478	14.0%
STEERING	21,197	6.3%
SERVICE BRAKES	16,177	4.8%
FORWARD COLLISION AVOIDANCE	15,662	4.6%
FUEL/PROPULSION SYSTEM	11,368	3.4%
AIR BAGS	10,934	3.2%
STRUCTURE	8,046	2.4%
VISIBILITY/WIPER	6,316	1.9%
EXTERIOR LIGHTING	6,231	1.8%
SUSPENSION	5,822	1.7%
ENGINE AND ENGINE COOLING	4,353	1.3%
VEHICLE SPEED CONTROL	4,008	1.2%

The top tier is unmistakable. ENGINE, ELECTRICAL SYSTEM, and POWER TRAIN occupy the first 3 positions by both complaint count and share. UNKNOWN OR OTHER also accounts for a substantial 47,478 complaints, which indicates that a notable portion of owner reports do not fit neatly into a more specific component bucket.

Below that top group, the complaint picture shifts toward control and safety-related systems. STEERING appears at 21,197, while SERVICE BRAKES and FORWARD COLLISION AVOIDANCE are close together at 16,177 and 15,662.

What owners are reporting most often

For readers searching phrases like “common car problems,” “common issues with car,” or “common car repair problems,” the findings support a straightforward answer: owners most often complain about the engine, the electrical system, and the power train.

The engine category alone stands at 72,435 complaints. That makes it the single most common complaint area in this dataset. Electrical issues are also prominent, with 58,223 complaints, suggesting that modern vehicle ownership problems are not limited to traditional mechanical failures. Power train complaints at 50,180 reinforce that drivability and transmission-related concerns remain central to owner dissatisfaction.

The next layer of complaints broadens the picture. STEERING at 21,197 and SERVICE BRAKES at 16,177 show that owners also report problems involving vehicle control. FORWARD COLLISION AVOIDANCE at 15,662 indicates that advanced driver-assistance systems are now a meaningful part of the complaint landscape as well.

This matters because it answers a common reader question about whether the most common problems are still “engine problems” in the old sense. The findings say yes, but not only that. Electrical and electronic systems are also among the most frequently cited complaint areas.

Engine and power-related issues dominate

Engine-related complaints are the clearest headline in the data. ENGINE leads at 72,435 and 21.4%, while ENGINE AND ENGINE COOLING adds another distinct category at 4,353 and 1.3%. FUEL/PROPULSION SYSTEM contributes 11,368 and 3.4%, and POWER TRAIN adds 50,180 and 14.8%.

Taken as listed categories, these findings show that many of the most common owner complaints involve the systems responsible for propulsion and operation. Readers asking about common car engine problems can be answered at the category level: engine complaints are the largest single complaint group in the findings, and related propulsion and power-train systems also rank high.

That does not mean every complaint is a catastrophic failure. The findings do not describe symptom detail, repair cost, or whether a vehicle became undrivable. But they do show where complaint volume is concentrated, and that concentration is heavily tilted toward engine and movement-related systems.

Electrical and technology complaints are a major theme

The second-largest category is ELECTRICAL SYSTEM, with 58,223 complaints and 17.2% share. That places electrical issues ahead of every category except engine.

This is one of the clearest signs in the findings that owner complaints are shaped by more than legacy mechanical wear. Modern vehicles depend on extensive electrical architecture, and the complaint totals show that owners report those issues at very high volume.

Technology-linked categories also appear elsewhere in the ranking. FORWARD COLLISION AVOIDANCE records 15,662 complaints and 4.6%, while VEHICLE SPEED CONTROL records 4,008 and 1.2%. These are not the largest categories, but they are large enough to show that driver-assistance and control systems are part of the mainstream complaint picture.

For readers asking why cars can feel troublesome, the findings suggest that complexity is part of the answer. Complaints are not confined to one old-fashioned failure point. They span engines, electronics, propulsion, steering, braking, and assistance systems.

Safety-related systems also appear prominently

Several complaint categories involve systems closely tied to occupant protection or vehicle control.

Safety-related component	Complaints	Share
STEERING	21,197	6.3%
SERVICE BRAKES	16,177	4.8%
FORWARD COLLISION AVOIDANCE	15,662	4.6%
AIR BAGS	10,934	3.2%
VISIBILITY/WIPER	6,316	1.9%
EXTERIOR LIGHTING	6,231	1.8%
VEHICLE SPEED CONTROL	4,008	1.2%

Among these, STEERING is the largest at 21,197. SERVICE BRAKES and FORWARD COLLISION AVOIDANCE follow closely. AIR BAGS at 10,934 show that passive safety systems also generate a meaningful volume of owner complaints.

This does not establish severity in any individual case, and the findings do not classify complaints by crash, injury, or repair outcome. Still, the presence of these categories near the upper half of the ranking shows that owner concerns extend well beyond inconvenience. Control, braking, visibility, and safety technology all appear in the complaint record.

What this does and does not say about the “worst cars”

Some reader questions ask which car has the most problems, what cars have the most problems, or which are the worst vehicles in 2024. These findings do not answer those questions.

The dataset is organized by component, not by make, model, brand, or model year. It identifies the most complained-about systems, not the most complained-about vehicles. It also does not provide problems per 100 vehicles, so there is no basis here for ranking vehicles on a normalized ownership metric.

What the findings can say is narrower but still useful. If the question is what owners complain about most across the US market, the answer is ENGINE at 72,435, followed by ELECTRICAL SYSTEM at 58,223 and POWER TRAIN at 50,180. If the question is whether common car problems are mostly mechanical, the answer is mixed: mechanical systems lead, but electrical and driver-assistance systems also account for substantial complaint volume.

Limitations

This findings document is a component-level snapshot computed in 2026. It does not include make, model, trim, age, mileage, repair history, or complaint narratives. It also does not separate minor issues from severe failures.

A further limitation is the size of UNKNOWN OR OTHER, which stands at 47,478 and 14.0%. That is one of the largest categories in the entire list. It means a significant share of owner complaints is not captured in the named component groups shown here.

The findings also do not provide trend data across 2024, 2025, or 2026. There is no time series in this document, so it cannot show whether any category is rising or falling. It is best read as a ranking of complaint concentration by component, not as a full diagnosis of reliability or safety performance.

Frequently asked questions

Q: What are the most common car problems? A: The largest complaint category is ENGINE with 72,435 complaints and 21.4%. It is followed by ELECTRICAL SYSTEM with 58,223 and 17.2%, and POWER TRAIN with 50,180 and 14.8%.

Q: What are common car engine problems? A: At the category level, ENGINE is the top complaint area with 72,435 complaints. Related categories also appear in the findings, including POWER TRAIN at 50,180, FUEL/PROPULSION SYSTEM at 11,368, and ENGINE AND ENGINE COOLING at 4,353.

Q: Are electrical issues a common car problem? A: Yes. ELECTRICAL SYSTEM is the second-largest category in the findings, with 58,223 complaints and a 17.2% share.

Q: Are safety systems a major source of complaints? A: Several safety-related systems appear prominently, including STEERING at 21,197, SERVICE BRAKES at 16,177, FORWARD COLLISION AVOIDANCE at 15,662, and AIR BAGS at 10,934.

Q: What car has the most problems? A: This findings document does not identify any specific car, brand, or model. It reports complaint totals by component, with ENGINE ranked first at 72,435.

Q: Does this show the worst vehicles of 2024? A: No. The findings do not include vehicle-level rankings or problems per 100 vehicles. They show component complaint totals, not the worst individual vehicles in 2024.