What Is the Most Common Cause of a Car Fire?

The most common cause of a car fire is mechanical failure or malfunction—most often fuel or other fluid leaks that ignite on hot engine or exhaust components. Data from U.S. fire safety agencies, including the National Fire Protection Association (NFPA), consistently show mechanical problems outpace electrical failures and crashes as the leading ignition source in highway vehicle fires.

How Car Fires Typically Start

Car fires generally begin when a combustible fluid or material meets sufficient heat and oxygen. In modern vehicles, that ignition often traces back to a mechanical problem—such as a leaking fuel line—coming into contact with hot surfaces like the exhaust manifold or catalytic converter. Electrical issues are the next most common culprit, followed by fires resulting from crashes.

Mechanical Failures: The Primary Driver

Mechanical failures create fire risk by introducing flammable liquids and vapors into hot zones under the hood or underbody. Heat from normal operation—especially in traffic or under heavy load—can be enough to ignite a small leak.

The following list outlines typical mechanical triggers emergency investigators frequently encounter.

• Fuel system leaks (gasoline or diesel) contacting hot engine or exhaust parts
• Oil or transmission fluid leaks dripping onto the exhaust or catalytic converter
• Overheating engines causing plastic, rubber, or wiring insulation to melt and ignite
• Worn or ruptured hoses and seals allowing flammable vapors to accumulate
• Clogged or failing catalytic converters running at abnormally high temperatures

Because fluids are both flammable and mobile, even minor leaks can spread quickly and ignite unexpectedly, especially after driving when under-hood temperatures peak.

Electrical Failures: A Close Second

Electrical faults are a major secondary cause, particularly in older vehicles or those with aftermarket wiring. While less common than mechanical failures overall, electrical problems can create high-heat arcing and ignite nearby materials.

The list below highlights recurring electrical hazards identified in vehicle-fire investigations.

• Damaged battery cables or corroded connections causing short circuits
• Overloaded circuits from add-on accessories drawing excessive current
• Chafed wiring harnesses that arc against metal components
• Faulty alternators or starters generating heat and sparks
• Improperly installed aftermarket audio, lighting, or remote-start systems

Electrical fires often begin invisibly behind panels or under the dash, making early detection harder and emphasizing the importance of proper fusing and professional installation.

What the Data Shows

NFPA analyses of U.S. highway vehicle fires (latest reports through the early 2020s) consistently find mechanical failure or malfunction to be the leading cause category, typically accounting for the largest share of incidents. Electrical failures rank second, with collisions and deliberate acts (arson) making up smaller portions. The engine area is the most common area of origin for moving vehicles, while arson is more likely in parked, unattended vehicles. Although electric vehicles receive attention when fires occur, internal-combustion vehicles account for the vast majority of highway vehicle fires due to the prevalence of liquid fuels and hot exhaust components.

Warning Signs to Watch For

Recognizing early indicators can help drivers act before a small problem becomes a fire.

• Smell of gasoline, burning oil, or melting plastic/rubber
• Visible fluid drips or puddles under the car after parking
• Smoke or steam from the hood, wheel wells, or underbody
• Electrical symptoms such as flickering lights, repeatedly blown fuses, or hot-to-the-touch switches
• Engine overheating, warning lights, or reduced power accompanied by unusual odors

If you notice these signs, pull over safely, turn off the engine, and seek professional help before continuing to drive.

What To Do If Your Car Catches Fire

Quick, calm action reduces risk to you and others. The steps below reflect standard guidance from fire safety officials.

1. Signal and pull over immediately to a safe, open area away from traffic and buildings.
2. Turn off the engine and set the parking brake; remove the key/fob.
3. Evacuate everyone right away; move at least 100 feet (30 meters) upwind.
4. Call emergency services and provide your exact location and vehicle description.
5. Do not open the hood or trunk—introducing oxygen can intensify the fire.
6. If the fire is very small and you have a suitable extinguisher (Class B/C), spray from a safe distance at the base of the flames; stop if it grows or smoke thickens.
7. Keep others away and wait for firefighters. Do not attempt to retrieve belongings.

Personal safety comes first; vehicles can be replaced, but rapid fire growth and toxic smoke can overwhelm occupants in seconds.

Prevention Tips

Routine maintenance and prudent habits greatly reduce the risk of a vehicle fire.

• Fix fluid leaks promptly; replace worn hoses, clamps, and gaskets.
• Maintain the cooling system and address overheating immediately.
• Have electrical work done by qualified technicians; use proper fuses and wire gauges.
• Avoid storing fuel cans, aerosol products, or lithium batteries loosely in the cabin/trunk.
• Keep the engine bay clear of debris; ensure heat shields are intact.
• For EVs and hybrids, follow manufacturer charging guidance and software updates; park away from combustibles if damage occurs until inspected.

While no vehicle is immune, a preventative mindset—backed by regular inspections—can significantly cut the odds of a fire.

Summary

Most car fires start with mechanical failure or malfunction, especially fuel or oil leaks igniting on hot engine or exhaust parts. Electrical faults are the next most common cause. Watch for warning signs like burning smells, fluid drips, and overheating, and prioritize maintenance and safe electrical practices. If a fire occurs, get everyone out, move a safe distance away, and call emergency services—do not open the hood or attempt risky firefighting.

What is the most common cause of car fires?

It’s important to act quickly if a vehicle catches fire. Burning vehicles can quickly trap occupants. Mechanical and electrical issues, along with crashes, are common causes of vehicle fires.

Why would a car suddenly burst into flames?

Fluid (especially fuel) leaks, electrical problems, crudely installed and/or low quality aftermarket accessories, design flaws, and driving over combustible materials like dried leaves or grass are the most common reasons. In some cases, an overheating engine or exhaust system could be a fire hazard too.

What is the most common way a vehicle fire can happen?

The most common causes of vehicle fires stem from a combination of factors, but fuel system leaks and electrical system failures, such as short circuits caused by damaged wiring, are among the most frequent culprits, often in conjunction with poor maintenance. Other causes include engine overheating from a faulty cooling system, a hot catalytic converter igniting dry vegetation, and even something as simple as rodents chewing on wires.
 
Common Causes of Vehicle Fires

• Fuel System Leaks: A leak in the fuel system is extremely dangerous because gasoline is highly flammable. These can result from rotten fuel lines or faulty connectors. 
• Electrical System Failures: A short circuit in the wiring can create a spark that ignites upholstery or other flammable materials. Faulty fuses, circuit breakers, and even damaged light bulbs can also lead to fires. 
• Engine Overheating: A failure in the engine’s cooling system, such as a leaking radiator or broken water pump, can lead to the engine overheating, increasing the risk of fire. 
• Hot Catalytic Converter: A clogged or overworked catalytic converter can become extremely hot and ignite surrounding materials or vegetation. 
• Aftermarket Accessories: Improperly installed aftermarket devices can introduce an electrical fault, inadvertently starting a fire. 
• Rodent Damage: Animals like rodents can chew through wires, particularly the soy-based insulation found in some modern vehicles, creating fire hazards. 

Prevention and Maintenance

• Regular Maintenance: Keeping up with your vehicle’s maintenance and having it serviced regularly is the best way to prevent fires caused by mechanical or electrical faults. 
• Don’t Ignore Warning Signs: Pay attention to dashboard warning lights, especially those indicating a high temperature, and don’t ignore the smell of gasoline. 
• Professional Inspections: Ensure that any aftermarket accessories are installed by authorized technicians to avoid introducing potential electrical faults. 

What cars are most likely to catch fire?

Hybrid vehicles currently have the highest rate of fires, with gasoline-powered cars second and electric vehicles (EVs) being the least prone to fires. Among specific models, Kias and Hyundais have a significant history of engine and electrical fires due to shared parts, while some high-end electric models like the Jaguar I-Pace have also faced fire recalls for battery issues. 
By Vehicle Type: 

• Hybrids: . Opens in new tabThese vehicles have the highest reported fire rate, at approximately 3,475.5 fires per 100,000 vehicles sold.
• Gasoline Cars: . Opens in new tabThese are the second most likely to catch fire, with a rate of 1,529.9 fires per 100,000 vehicles sold.
• Electric Vehicles (EVs): . Opens in new tabEVs have the lowest fire risk, with a rate of just 25.1 fires per 100,000 vehicles sold.

By Manufacturer/Model:

• Kias and Hyundais: These brands have a high risk due to shared parts leading to issues like engine oil leaks, faulty rod bearings, and electrical shorts. Recalls have affected millions of vehicles. 
• Specific Hybrid Models: The Hyundai Tucson and Sonata hybrids have been recalled due to issues that could cause engine fires. 
• Electric Models with Issues: The Jaguar I-Pace has had a high number of recalls for battery overheating, which can lead to fires, and owners are advised to park the vehicle away from structures. 
• Historical Examples: The Ford Pinto is infamous for a design flaw that caused its gas tank to rupture and cause fires in collisions. 

Why Hybrids are More Prone to Fires:

• The combination of a traditional gasoline engine, an electric battery, and the complex systems that manage both can lead to more potential points of failure. 
• While the exact reasons are still being studied, the high-voltage systems and the overlap of gasoline and electric components are believed to contribute to the elevated risk, according to a YouTube video.