Why Cars Catch Fire: The Leading Cause and How to Prevent It

The most common reason a car catches fire is a mechanical failure or malfunction—especially a flammable fluid leak in the engine compartment that ignites on a hot surface like the exhaust manifold or catalytic converter. Data from fire agencies consistently show mechanical issues as the top ignition factor, followed by electrical faults; crashes and arson are less frequent causes. Understanding how these fires start can help drivers spot warning signs early and reduce risk.

What the Data Shows

Fire incident data in the United States indicate that mechanical failure or malfunction is the leading factor contributing to ignition in highway vehicle fires. Analyses by national fire organizations consistently report that such failures account for the largest share of incidents, with electrical distribution and wiring problems ranking second. Heat from powered vehicle components (for example, hot exhaust parts) is a frequent heat source, and the engine compartment is the most common area of origin. While collisions can cause fires, they represent a smaller portion of total incidents compared with mechanical and electrical issues.

How Mechanical Failures Ignite Fires

Most vehicle fires begin with an ordinary mechanical problem that becomes hazardous under the hood. Leaks of gasoline, diesel, engine oil, power-steering fluid, transmission fluid, or brake fluid can drip or spray onto hot components. Exhaust manifolds and catalytic converters can easily exceed several hundred degrees, hot enough to ignite vapors or oil-soaked materials. In parallel, chafed wiring or loose connections can arc, creating sparks that ignite nearby fluids or plastic components. Once ignited, composite body panels, insulation, and wiring sheathing can accelerate fire spread.

Other Common Causes Worth Noting

While mechanical failure leads overall, several other scenarios also contribute to vehicle fires. The following list outlines additional causes drivers and technicians should keep in mind.

• Electrical faults: short circuits, deteriorated insulation, overloaded accessory circuits, or incorrect fuses leading to overheating and arcing.
• Crashes and rollovers: damaged fuel tanks or lines, ruptured high-voltage battery packs, and pinched wiring after severe impacts.
• Overheated catalytic converters: igniting oil residue or dry vegetation trapped under the vehicle.
• Aftermarket modifications: poor-quality or improperly fused audio gear, lighting, remote starters, or engine tunes increasing electrical load or heat.
• EV and hybrid battery thermal runaway: rarer than liquid-fuel fires overall but potentially more persistent once initiated; typically triggered by crash damage, manufacturing defects, or improper repair/storage.
• Arson and intentional fires.

Although these factors are less common than routine mechanical malfunctions, they underscore how varied vehicle fire risks can be—spanning fuel systems, wiring, crash damage, and even parked-vehicle conditions.

Warning Signs to Watch For

Early detection often prevents small faults from becoming fires. Drivers should pay attention to the following red flags during daily use and routine checks.

• Smell of gasoline, raw fuel, or sweet/chemical odors (coolant or other fluids).
• Visible drips or wet spots under the car; oily residue around hoses, fittings, or the engine.
• Smoke, steam, or a burning-plastic/rubber smell from the engine bay or wheel wells.
• Dashboard warning lights (battery/charging, temperature, oil pressure) or repeatedly blown fuses.
• Loose, cracked, or brittle wiring; melted connectors; flickering lights; hot-to-the-touch fuse box.
• Unusually high engine temperature or the fan running constantly; catalytic converter glowing red.
• Rattling heat shields or debris trapped near the exhaust or underbody.
• Open recalls related to fuel systems, batteries, or electrical components.

Treat these symptoms as urgent: isolating the vehicle, inspecting for leaks, and scheduling prompt repairs can avert an ignition event.

Prevention Tips That Make the Biggest Difference

Routine maintenance and a few careful habits dramatically reduce the risk of a vehicle fire. Use the guidelines below to target the highest-impact steps.

• Fix fluid leaks immediately and replace brittle hoses, clamps, and gaskets at the first sign of seepage.
• Keep the engine compartment clean; remove oil residue and road debris that can smolder on hot parts.
• Protect wiring from chafing; secure harnesses and replace damaged insulation and corroded connectors.
• Use the correct fuses and avoid overloading accessory circuits; have aftermarket electronics professionally installed.
• Do not ignore warning lights; address charging, temperature, and oil-pressure issues promptly.
• Park clear of dry grass or leaves that can contact a hot catalytic converter or exhaust.
• Check for and complete safety recalls; follow manufacturer service intervals for both ICE and EV/hybrid systems.
• For EVs/hybrids, use approved charging equipment, avoid charging on damaged outlets, and have HV repairs done by certified technicians.

These steps aim to remove fuel sources, minimize ignition sources, and ensure protective systems operate as designed—collectively the most effective way to prevent fires.

What To Do If You Suspect or See a Fire

If a fire starts or you suspect one, quick, safe action is essential. The following steps prioritize getting people away from danger and limiting escalation.

• Signal, pull over safely, shift to Park, and turn off the engine to cut fuel and electrical power.
• Evacuate everyone immediately; move at least 100 feet upwind and uphill if possible.
• Call emergency services; provide location and note if the vehicle is an EV/hybrid for responder awareness.
• Do not open the hood—introducing oxygen can intensify flames.
• Use a Class B/C (or ABC) extinguisher only if the fire is very small, confined, and you have a clear exit.
• Do not use water on fuel or electrical fires; for EV batteries, do not attempt to extinguish—leave it to trained responders.

Personal safety comes first. Vehicles are replaceable, and professional responders are best equipped to handle advanced hazards, especially high-voltage systems.

Summary

The most common reason cars catch fire is mechanical failure or malfunction—most often a flammable fluid leak igniting on hot engine or exhaust components—with electrical faults the next leading contributor. Watch for odors, leaks, smoke, and warning lights; fix issues promptly; keep wiring and engine bays clean; and complete recalls. If a fire starts, shut down, evacuate, and call for help—don’t open the hood or take risks. Proactive maintenance remains the single most effective fire prevention strategy for any vehicle, gasoline or electric.

What is the most common cause of car fires?

The most common causes of car fires are fuel system leaks, where flammable liquids ignite from a spark or hot engine component, and electrical system failures, which can cause sparks from faulty wiring or components. Poor vehicle maintenance can lead to both of these issues, increasing the risk of a fire from damaged wires or leaking components. 
Causes of Car Fires

• Fuel System Leaks: Flammable liquids like gasoline can leak from damaged lines or components and contact a hot engine part or a spark, leading to ignition. 
• Electrical System Failures: Worn or damaged wiring, short circuits, or faulty components can create sparks or heat, igniting nearby materials. 
• Poor Maintenance: Neglecting regular maintenance can result in damaged electrical wires, leaky fuel lines, or engines that overheat, all of which are fire hazards. 
• Engine Overheating: Overheating can cause fluids to spill and come into contact with hot engine components or wires. 
• Car Accidents: A collision can cause damage to the fuel tank, fuel lines, or electrical systems, leading to leaks, sparks, and potential ignition of flammable liquids. 
• Catalytic Converter Issues: A damaged or improperly functioning catalytic converter can become extremely hot and pose a fire risk if it contacts foreign objects. 

Prevention

• Perform Regular Maintenance: Have your car inspected and serviced regularly to catch potential problems with the fuel and electrical systems. 
• Be Vigilant for Leaks: If you smell gasoline or see fluid leaks under your car, get it checked and fixed immediately. 
• Address Electrical Issues: Don’t ignore warning signs of electrical problems, such as flickering lights or other malfunctions. 

How likely is it for a car to catch on fire?

While not extremely common, car fires still happen with some frequency, with statistics varying by source and year, but generally indicating hundreds of thousands of incidents annually in the U.S.. Mechanical or electrical failures are the most frequent causes, with collisions accounting for a smaller percentage of fires but a higher number of fatalities. 
Frequency of Car Fires

• National Fire Protection Association (NFPA) estimates Opens in new tabsuggest that annual vehicle fires average around 119,000 to 152,000 in the U.S. 
• Fire-related data Opens in new tabshows that vehicle fires account for about one in every eight reported fires and one in eight fire deaths. 

Causes of Vehicle Fires

• Mechanical or Electrical Failures Opens in new tabare the primary cause of most car fires, responsible for about two-thirds of incidents. 
• Collisions Opens in new tabcontribute to a smaller percentage of highway vehicle fires (about 4%) but are responsible for a disproportionately high number of deaths. 
• Fuel Leaks Opens in new tabare particularly dangerous, as a small number of fuel-related fires account for a larger portion of fire deaths. 

Key Takeaways

• Car fires are a significant, albeit not the most common, type of fire incident. 
• Preventive maintenance and addressing mechanical or electrical issues can reduce risk. 
• While less frequent, accident-related fires pose a greater risk of injury and death, according to the U.S. Fire Administration (USFA). 

Why would a car get caught on fire?

Usually cars catch fire due to the exposure of flammable liquids (such as gasoline) to surfaces hot enough to ignite them. This might be the exterior of a running engine, especially one which is damaged, or simply the sparks produced by forceful contact between steel or iron within a collision.

What is the most common car to catch fire?

Hybrid cars have the highest fire risk per 100,000 vehicles sold, followed by traditional gasoline-powered cars. While individual models like the Jaguar I-Pace and older Hyundai and Kia models had specific issues, the overall data indicates that hybrid vehicles are significantly more prone to fires than electric or gasoline cars.
 
Statistics by Vehicle Type 

• Hybrid Cars: Opens in new tabThe most fire-prone type, with around 3,475 fires per 100,000 vehicles sold.
• Internal Combustion Engine (ICE) Cars: Opens in new tabHave a lower risk than hybrids, with approximately 1,530 fires per 100,000 vehicles sold.
• Electric Vehicles (EVs): Opens in new tabHave the lowest fire risk, with only about 25 fires per 100,000 vehicles sold, according to a recent study.

Factors Contributing to Fires

• Hybrid and Gas Car Fires: Opens in new tabThe primary causes are issues related to fuel leaks, electrical shorts, and problems with components like anti-lock braking systems (ABS). 
• Electric Car Fires: Opens in new tabThe main risk for EVs is their batteries. While less frequent, these fires can be intense and difficult to extinguish. 

Why the Perception Differs 

• Over-Reporting of EV Fires: Opens in new tabDespite being rarer, EV fires are often more publicized and heavily reported in the news, leading to a perception that they are more common than they are.
• Under-Reporting of Gas Car Fires: Opens in new tabMost fires in traditional gasoline-powered cars do not make the news, so the actual number of fires is often underestimated.