Rank vehicle components by how many complaints they generate and you learn which faults are most common. Airbags, powertrain and electrical systems dominate, and that ranking gets published often.
Rank them by what happened to the people involved and the list rearranges.
| Component | Complaints | Deaths | Injuries | Deaths per 1,000 |
|---|---|---|---|---|
| Tyres | 16,729 | 250 | 1,370 | 14.94 |
| Speed control | 26,403 | 215 | 2,703 | 8.14 |
| Air bags | 83,738 | 510 | 19,819 | 6.09 |
| Seat belts | 14,682 | 83 | 1,765 | 5.65 |
| Fuel system | 25,261 | 127 | 432 | 5.03 |
| Power train | 91,494 | 169 | 1,803 | 1.85 |
| Steering | 63,778 | 108 | 1,471 | 1.69 |
| Suspension | 31,668 | 51 | 679 | 1.61 |
Powertrain generates five and a half times more complaints than tyres and produces fewer deaths. The rate differs by a factor of nine.
Why tyres top the list
Tyre complaints are relatively rare because a tyre problem is usually handled rather than reported — you notice a bulge, you replace it, nobody files anything.
What does get filed is the other kind: a failure at motorway speed. A tread separation or a blowout at seventy removes steering and braking simultaneously, and there is no version of that event where the driver has time to react thoughtfully.
So the complaint population for tyres is skewed toward catastrophic outcomes, in a way the population for powertrain complaints is not. A transmission that fails leaves you at the roadside; a tyre that fails leaves you crossing a lane.
Airbags are the largest absolute number
Per complaint, airbags rank third. In total human cost they are first by a distance: 510 deaths and 19,819 injuries.
The injury figure is the one to notice. It is ten times larger than the next component on the list, and it reflects a specific history — inflator failures that sent metal fragments into the cabin, affecting tens of millions of vehicles across many manufacturers.
It also reflects the awkward fact that an airbag is a small explosive charge fired at a person's chest. When it works correctly it saves lives on a scale nothing else in the car matches. When it fires wrongly, or does not fire, the outcome is recorded here.
Brakes fail differently
Brakes do not appear near the top of the death rate, but they lead a different measure entirely: 7.4% of brake complaints involve a crash, the highest crash rate of any component.
That is the distinction worth holding onto. Brake failures produce collisions, usually at whatever speed the traffic was doing, and collisions at ordinary speeds are survivable far more often than a loss of control at motorway speed.
Two components, two different failure shapes, and a ranking by deaths alone would tell you brakes are safe. They are not — they simply fail toward a different outcome.
What this changes
The practical version is about maintenance priorities, and it points somewhere unfashionable.
Tyres are the cheapest safety-critical component on a car and the one owners defer longest, because a worn tyre works fine right up until it does not. On this data they are also the component whose failures are most likely to kill somebody.
Age matters as much as tread depth — rubber degrades whether or not the car is driven, which is why a low-mileage older vehicle can be sitting on tyres that look fine and are a decade past their date code.
For the components that do get recalled, the remedy is free and tied to the vehicle rather than the owner. A free VIN check shows which campaigns are still open on a specific car.
Frequently asked questions
Which car faults are most likely to kill someone?
Tyres, by a wide margin: 14.94 deaths per 1,000 complaints, against 8.14 for speed control and 6.09 for airbags. Tyre complaints are relatively uncommon — 16,729 records — but the ones that get filed describe failures at speed with nowhere to go.
How many complaints involve a fatality?
1,562 out of 1,105,355, which is 0.141%. The overwhelming majority of complaints describe faults that frightened, stranded or annoyed someone rather than injured them, which is why volume alone is a poor guide to severity.
Are airbag complaints dangerous?
They carry the highest absolute toll — 510 deaths and 19,819 injuries — spread across 83,738 complaints. Per complaint the rate is lower than tyres, but airbags generate far more reports, and the injury figure is the largest of any component by an order of magnitude.
Should I worry more about brakes or tyres?
Tyres, on this evidence, though both deserve attention. Brake complaints involve a crash 7.4% of the time — the highest crash rate of any component — while tyre complaints are more likely to end in a fatality when they do go wrong. Brakes fail toward a collision; tyres fail toward a loss of control at speed.
Denis Kataev is a serial solopreneur and the founder of ForCar. With 15+ years in software engineering and 10 years in SEO, he builds data-driven products end to end — backed by a sharp eye for design. At ForCar he mines proprietary vehicle datasets, turning raw numbers into buying advice you can actually trust.
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