Why a Car Might Catch Fire While Driving

Cars most commonly catch fire while driving due to flammable fluid leaks onto hot engine or exhaust parts, electrical shorts or overloading in wiring, overheating components like catalytic converters, wheel or brake failures that generate extreme heat, collisions, and—more rarely in hybrids and EVs—battery damage leading to thermal runaway. Heat, motion, and airflow at speed can turn a small fault into a fast-moving blaze, so the immediate priorities are to pull over safely, shut the vehicle off, evacuate, and call emergency services.

What Typically Ignites a Moving Vehicle

While modern vehicles include multiple safeguards, several failure modes can ignite a fire when the car is under load and producing heat. The following are the most frequent root causes mechanics and investigators see on the road.

• Fuel or oil leaks: Gasoline, diesel, engine oil, transmission fluid, and power-steering fluid can drip onto hot exhaust manifolds or catalytic converters and ignite.
• Electrical faults: Chafed wiring, loose battery terminals, corroded grounds, failing alternators, aftermarket accessories without proper fusing, or rodent-damaged harnesses can spark and start fires.
• Overheated exhaust/catalytic converter: Misfires or a clogged converter can superheat the exhaust, igniting underbody insulation, plastics, or roadside debris lodged under the car.
• Brakes and wheel-end failures: A seized brake caliper or wheel bearing can generate enough heat to ignite grease, the brake assembly, or the tire.
• Cooling system or engine failures: Overheating, head-gasket failures, or coolant/oil spraying onto hot parts can lead to ignition; turbocharger failures can also superheat nearby components.
• Collisions and road debris: Impact can rupture lines or damage high-voltage components; debris can puncture underbody parts or become wedged near hot exhaust sections.
• Improper modifications: Non-OEM fuel system changes, incorrect wiring, oversize fuses, and poorly installed audio or remote-start systems raise fire risk.
• Cargo and behavior: Carrying gasoline cans inside the cabin, smoking near vapors, or aerosol cans left in heat can contribute to ignition.

In essence, fires in moving vehicles tend to start where heat and fuel meet: hot exhaust pieces, energized wiring, and friction-heavy wheel assemblies are the usual ignition points.

Warning Signs You May Notice Before a Fire

Drivers often get clues that a component is failing or that a fire risk is developing. Recognizing these signs early can prevent a blaze or allow you to stop safely.

• Smells: Sharp fuel odor, hot/burning plastic, burning rubber, or acrid electrical smell.
• Smoke: Wisping from vents or the hood, or smoke trailing from a wheel well.
• Warning lights: Battery/charging, temperature, oil pressure, or hybrid/EV system alerts.
• Electrical anomalies: Flickering lights, repeatedly blown fuses, hot-to-the-touch fuse box, or unusual clicking near relays.
• Performance changes: Sudden misfires, loss of power, backfiring, or rough running that can overheat the catalytic converter.
• Brake issues: Pulling to one side, burning smell after light use, smoke from a wheel, or severe brake fade.
• Noises: Grinding or howling from a wheel (possible bearing failure), popping sounds from the engine bay.
• Visible leaks: Oily sheen or puddles under the car; fluids dripping near the exhaust.
• Underbody scraping: A plastic splash shield or debris contacting hot exhaust components.

If you detect these signs, reduce speed, find a safe place to pull over, and investigate from a distance. Small issues escalate quickly in motion due to airflow feeding a nascent flame.

What To Do Immediately If Your Car Catches Fire

Swift, calm action is critical. Your goal is to get everyone out safely, prevent the fire from growing, and alert responders. Only attempt to extinguish a tiny, contained fire if you have the right extinguisher and a clear escape route.

1. Signal, pull over, and stop in a safe area away from traffic and buildings; shift to Park and set the parking brake.
2. Turn off the engine and, if safe, switch off the HVAC to reduce airflow that can fan flames.
3. Evacuate everyone immediately; move at least 100–150 feet (30–45 meters) upwind and uphill if possible.
4. Call emergency services; give your location, vehicle type (gas, diesel, hybrid, EV), and whether flames or smoke are visible.
5. Warn other motorists from a safe distance; use hazard lights and, if available, place triangles well behind the vehicle.
6. Do not open the hood or trunk—introducing oxygen can cause a flare-up.
7. Use a Class B/C or ABC extinguisher only for a very small, accessible fire (for example, a smoldering mat), aiming at the base from a safe distance; abandon efforts if it grows or you feel unsafe.
8. Do not remove the radiator cap or touch hot components; wait for firefighters to declare the scene safe.

Prioritize life over property. Vehicles burn quickly, and toxic smoke can incapacitate. Once you are safe and help is on the way, do not reapproach the car.

How to Lower the Risk

Most vehicle fires are preventable with routine maintenance, mindful driving, and attention to recalls. The checklist below targets the highest-risk systems and habits.

• Fix leaks promptly: Address fuel, oil, power-steering, and transmission-fluid leaks; damp, oily engine bays are a major hazard.
• Maintain ignition and exhaust systems: Repair misfires; replace clogged catalytic converters; keep heat shields and underbody panels intact.
• Care for brakes and wheel bearings: Service dragging brakes; replace noisy bearings; ensure proper torque on lug nuts.
• Protect the electrical system: Use correct fuses; secure batteries; avoid overloading outlets; professionally install accessories with proper gauge wire and fusing.
• Keep the engine bay clean: Remove leaves and debris that can smolder on hot parts.
• Mind cargo and habits: Never carry fuel containers in the cabin; avoid smoking near fuel vapors; store aerosols out of heat.
• Watch for rodent damage: Inspect wiring if the vehicle sits outdoors; use deterrents or covers as needed.
• Check recalls and TSBs: Search your VIN on your national safety agency’s database (e.g., NHTSA in the U.S.) and complete recall work promptly.
• Respond to warning lights: Overheating, charging faults, or hybrid/EV system alerts warrant immediate inspection.
• Consider an in-vehicle extinguisher: An ABC extinguisher mounted securely and reachable can stop a small fire before it grows—use only if trained and safe to do so.

Consistent maintenance and swift attention to early symptoms dramatically reduce the odds of a fire and limit severity if one starts.

Special Considerations for EVs and Hybrids

Pure EVs and hybrids have different risk profiles. Most highway vehicle fires still involve gasoline vehicles, but high-voltage systems require specific caution when damaged or overheating—especially after impacts or underbody strikes.

• Crash or debris damage: Impacts can compromise battery cells or high-voltage cabling, leading to delayed thermal runaway—sometimes hours after an incident.
• Thermal warnings: Heed messages about battery temperature, HV system faults, or “service vehicle soon.” Reduce load and stop safely.
• Charging and coolant issues: Battery coolant leaks or charging faults can trigger warnings; do not continue driving—seek service.
• Reignition risk: Damaged packs can rekindle; responders may monitor a vehicle for an extended period. If advised after a crash, park outside away from structures.
• 12-volt side still matters: Many EV fires traced to conventional 12V wiring, DC-DC converters, or accessory faults—treat these like any other electrical risk.
• Do not apply water yourself: High-voltage fires require specialized tactics and large water volumes; evacuate and call professionals.

While EV battery fires are comparatively rare, any high-voltage alert, unusual odor, or underbody strike warrants caution: stop, exit, and arrange a tow to a qualified service center.

Why Movement Matters

Driving raises temperatures across the powertrain, exhaust, brakes, and tires. Airflow at speed can both hide early smoke and, once flames start, feed them like a bellows. Leaks are more likely to reach hot components as fluids are pressurized and slosh under acceleration, and friction-related failures (brakes, bearings) only develop heat while moving.

After a Fire: Insurance and Investigation

Once everyone is safe and the fire is out, the next steps focus on documentation, cause analysis, and claims. The outline below helps protect your interests.

• Document the scene: If safe, photograph the vehicle, surroundings, and any warning lights or damage; note times and locations.
• Obtain reports: Ask for the fire department and police incident numbers; these support the claim and any investigation.
• Notify your insurer promptly: Provide VIN, mileage, and any recent repair/recall paperwork; do not authorize teardown without the adjuster’s approval.
• Preserve evidence: Do not remove parts; potential subrogation (e.g., against a component supplier) may depend on untouched evidence.
• Check for recalls: If a known defect is involved, manufacturers may assist; complete open recalls on other vehicles you own.
• Plan for total loss: Many fire-damaged vehicles are not economical to repair; confirm title, payoff, and rental/transport benefits.

Clear records, official reports, and careful handling of the vehicle after the incident streamline claims and help determine the root cause.

Summary

A car can catch fire while driving when heat, fuel, and ignition sources converge—most often from fluid leaks onto hot parts, electrical faults, overheated exhaust or brakes, and crash damage. Heed early warning signs, stop and evacuate quickly, and call emergency services. Preventive maintenance, proper wiring and fusing, and prompt recall repairs significantly reduce risk. While EV-related fires are uncommon, damaged high-voltage systems demand extra caution and professional response.

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

Car fires are rare, but not uncommon; the National Fire Protection Association (NFPA) estimates about 215,000 vehicle fires annually in the U.S., representing a roughly 0.04% annual chance of fire for a vehicle on the road. The main causes are mechanical failures (44%) and electrical malfunctions (32%), which ignite flammable liquids, fumes, or other materials under the hood or in the vehicle.
 
Statistics

• Frequency: The NFPA reports over 200,000 vehicle fires annually in the U.S. 
• Likelihood: Given millions of registered vehicles, the chance of any single vehicle catching fire is very low. 

Common Causes

• Mechanical Failures: A leading cause, including issues with engine oil levels, overheating brakes, and other engine or component failures. 
• Electrical Malfunctions: Cracked or damaged wiring, short circuits, and other issues with the vehicle’s electrical system. 
• Flammable Liquids: Gasoline, diesel fuel, and other fluids can catch fire if their containers, hoses, or lines are damaged. 
• Fume Ignition: Accumulation of flammable vapors that can be ignited by a spark or hot surface. 
• Wear and Tear: Age and poor maintenance can lead to various issues that increase fire risk. 
• Design Flaws: Defects from the manufacturer can also contribute to vehicle fires. 

Prevention Tips

• Regular Maintenance: Follow your car’s recommended maintenance schedule to catch potential issues early. 
• Professional Inspections: Have your vehicle checked by a qualified mechanic for any signs of leaks or electrical problems. 
• Keep it Clean: Don’t store flammable materials like rags or paper towels under the hood, as they can ignite. 
• Be Aware of Recalls: Stay informed about safety recalls, as they often relate to defects that can increase the risk of fire. 

What part of a car is most likely to catch fire?

1: Fuel System Leaks. Leaks in the fuel system are the most common cause of vehicle fires, so that’s why they take the top spot on our list. A fuel system leak is really dangerous.

What would make a car set on fire?

Cars catch fire due to a combination of flammable fluids (like fuel or oil), an ignition source (such as a spark from a damaged electrical system or a hot exhaust), and the presence of oxygen. Major causes include faulty fuel and electrical systems, engine or exhaust overheating, and mechanical or manufacturing defects, often accelerated by a lack of proper vehicle maintenance or by accidents that damage critical components. 
Common Causes of Car Fires

• Fuel System Issues: Leaks from damaged or poorly routed fuel tanks, lines, or injectors can release flammable gasoline, which can ignite from a spark or hot surface. 
• Electrical System Failures: Exposed or damaged wiring from wear, accidents, or even rodent damage can short-circuit and create sparks, igniting fuel or other nearby materials. 
• Overheating: An engine can overheat from a lack of coolant, an engine oil leak, or a failing water pump. The exhaust system, especially the catalytic converter, can also become extremely hot and ignite flammable debris or fluids that come into contact with it. 
• Mechanical Failures: Issues with components like a faulty battery, worn hoses, or other mechanical defects can lead to leaks or sparks that start a fire. 
• Defects and Debris:
  • Design/Manufacturing Defects: Faults in a vehicle’s design or manufacturing process can create inherent risks for fire, such as faulty ground bolts or wiring issues, as seen in some recalled vehicles. 
  • Flammable Debris: Accumulation of oily rags, spilled fluids, or dry vegetation under the vehicle can increase the risk of fire if they come into contact with a heat source. 
• Accidents: Crashes can rupture fuel lines and tanks, damage electrical systems, or damage engine components, leading to leaks and sparks that can quickly ignite. 
• Poor Maintenance: A lack of regular vehicle maintenance is a frequent human-caused factor, as it contributes to the development of leaks, worn wiring, and other mechanical issues that can lead to fires. 

This video explains the common causes of car fires: 1mBig QuestionsYouTube · Mar 8, 2025
Preventing Car Fires

• Perform Regular Maintenance: Follow your vehicle’s recommended maintenance schedule to address issues like fluid leaks, wiring problems, and engine overheating early. 
• Check for Leaks: Be vigilant for puddles of oil, coolant, or fuel under your car, especially after an oil change. 
• Inspect Wiring: Periodically check under the hood and dashboard for any signs of cracked or damaged wiring. 
• Address Warning Lights: Pay attention to dashboard warning lights, especially those related to temperature or fuel. 
• Be Aware of Odors: Promptly investigate unusual smells, such as burning rubber or metal, which could indicate a developing fire hazard. 
• Report Recalls: Respond to manufacturer recalls for potential design or manufacturing defects that could lead to a fire. 

Why do cars catch fire while driving?

Cars can catch fire while driving due to fuel or oil leaks igniting on hot engine parts, faulty or exposed wiring causing sparks, and overheating from engine or exhaust system issues. Other causes include manufacturing defects, improper maintenance, flammable debris in hot areas like the engine bay or exhaust, and issues with the catalytic converter. A collision can also damage fuel or electrical systems, leading to a fire.
 
Causes related to fluids:

• Fuel Leaks: Opens in new tabGasoline is highly flammable and leaking fuel can come into contact with hot engine components or exhaust manifold, leading to ignition. 
• Oil and Fluid Leaks: Opens in new tabLeaks of engine oil, brake fluid, or other flammable fluids can accumulate on hot engine parts or the exhaust system, causing a fire. 
• Engine Overheating: Opens in new tabA lack of coolant or a failing cooling system can cause the engine to overheat, potentially leading to fluid spills onto hot surfaces. 

Causes related to the electrical system:

• Faulty Wiring: Opens in new tabDegraded insulation on wiring, loose connections, or exposed metal can create sparks that ignite leaking fuel or other flammable materials. 
• Short Circuits: Opens in new tabMalfunctioning electrical components or improper installations of aftermarket parts can cause short circuits and create ignition sources. 
• Battery Issues: Opens in new tabA damaged or faulty car battery can also be a source of sparks and heat that may trigger a fire. 

Other Contributing Factors:

• Poor Maintenance: A lack of regular maintenance can lead to various issues, such as fluid leaks, damaged wiring, and overheating, all of which increase fire risk. 
• Catalytic Converter Issues: A catalytic converter that overheats due to a clog or a missing heat shield can become hot enough to ignite debris on the underside of the car. 
• Flammable Debris: Flammable materials, such as spilled oil, gasoline, or accumulated dirt, under the hood or near hot components like the exhaust can easily catch fire. 
• Design or Manufacturing Defects: Some cars have design flaws or manufacturing defects that can increase the risk of fire under specific circumstances. 
• Accidents: A car accident can damage the fuel tank or electrical wiring, causing leaks or sparks that lead to a fire.