Do most vehicle fires start in the engine?

Yes. Analyses by U.S. fire-safety agencies show that a majority—roughly six in ten—highway vehicle fires originate in the engine compartment, running gear, or wheel area. This pattern has been consistent across multiple multi-year studies and remains the dominant area of origin for fires in gasoline and diesel vehicles.

What the data shows

National data has long pointed to the engine compartment and closely adjacent components as the most common area of origin for vehicle fires. The National Fire Protection Association’s “Highway Vehicle Fires” report (authored by Marty Ahrens) and the U.S. Fire Administration’s Topical Fire Report Series have each found that about 60% or more of highway vehicle fires begin in the engine area, running gear, or wheel well. While exact percentages vary by study period, the conclusion is consistent: the engine and its immediate systems are the primary ignition zones for most vehicle fires.

These reports also highlight that mechanical failures (for example, worn or heat-stressed components, fluid leaks onto hot surfaces) and electrical malfunctions (wiring shorts, faulty connections) are leading contributing factors. Although modern vehicles incorporate extensive fire-resistant design and protective controls, the combination of heat, flammable liquids, vibration, and complex electrical systems keeps the engine bay a hotspot for ignition.

Why the engine compartment is a hotspot

Several engineering and operational realities make the engine bay the most likely place for a fire to start in internal-combustion vehicles. The factors below summarize what investigators and safety agencies frequently identify at the scene.

• High heat and ignition sources: Exhaust manifolds, catalytic converters, and turbochargers operate at very high temperatures that can ignite nearby combustibles.
• Flammable liquids under pressure: Fuel and oil can leak from aging lines, fittings, or gaskets, especially under load, and ignite on hot surfaces.
• Electrical complexity: Tight engine compartments house extensive wiring, connectors, and control modules; chafed insulation or poor connections can arc and spark.
• Wear, vibration, and age: Heat cycles and vibration degrade hoses, seals, and insulation over time, increasing the risk of leaks and shorts.
• Brakes and wheels: Overheated brakes or wheel bearings can kindle fires in the wheel area that spread to the engine compartment.
• Aftermarket modifications: Non-OEM electrical add-ons or performance parts installed without proper protection can introduce new ignition hazards.

Together, these conditions create a challenging environment where a single failure—especially in older or poorly maintained vehicles—can escalate into a fire.

How EVs and hybrids compare

Fleet composition matters: most highway vehicle fires still involve gasoline and diesel vehicles, simply because they dominate the on-road population. Battery-electric vehicles (EVs) have a different risk profile. Their fires are less likely to begin in an “engine” (there isn’t one), and when fires do occur, they often involve high-voltage batteries, power electronics, or charging equipment. Available studies to date suggest EV fires are comparatively infrequent per registered vehicle, though data sets are still maturing and incident characteristics differ from internal-combustion fires. Hybrids include both high-voltage components and engines, so areas of origin can include either the engine bay or the battery and related systems. Fire-service training materials from NFPA and safety advisories from NHTSA emphasize the unique suppression challenges of lithium-ion battery fires, even as overall incidence remains low compared with traditional engine-compartment fires.

What drivers can do to reduce the risk

Routine maintenance and a few simple habits meaningfully lower the odds of a vehicle fire, particularly in the engine compartment and wheel areas.

• Fix leaks promptly: Address fuel, oil, and coolant leaks and replace cracked or brittle hoses and seals.
• Inspect electrical systems: Look for chafed wiring, loose grounds, corroded connectors, and improper aftermarket splices or fuses.
• Maintain brakes and wheel bearings: Overheating here can ignite nearby materials; make sure components are serviced on schedule.
• Respond to warning signs: Burning smells, smoke, fluid drips, sudden temperature spikes, or flickering lights warrant immediate inspection.
• Follow recalls and technical service bulletins: Manufacturer fixes often address known fire risks; check your VIN periodically.
• Be cautious with add-ons: Use vehicle-specific, properly fused accessories installed to OEM standards.
• Carry a small ABC fire extinguisher if permitted: Only use it on a very small, early-stage fire and at a safe distance.

These steps don’t eliminate risk, but they significantly reduce the likelihood that a minor fault in the engine bay or wheel area turns into a fire.

What to do if your vehicle smokes or catches fire

If you suspect a fire, act quickly and prioritize safety. The following actions align with guidance from fire-safety authorities.

1. Pull over safely: Signal, move to the shoulder or a safe area, and stop the vehicle.
2. Shut it down: Turn off the engine and set the parking brake to cut heat and fuel flow.
3. Evacuate immediately: Get everyone out and move at least 100 feet upwind and uphill if possible.
4. Call emergency services: Dial 911 and provide your location and a description of the situation.
5. Do not open the hood: Introducing oxygen can intensify the fire; keep a closed hood between you and flames.
6. Use an extinguisher only if safe: If the fire is small and contained (for example, at a wheel), use an ABC extinguisher from a safe distance and be prepared to retreat.
7. Warn others: Keep bystanders away and alert oncoming traffic if safe to do so.
8. Wait for professionals: Do not re-enter the vehicle until responders declare it safe.

Rapid evacuation and a cautious approach protect you and others; vehicles are replaceable, people are not.

Summary

Most vehicle fires do start in or near the engine—specifically the engine compartment, running gear, or wheel area—according to longstanding NFPA and USFA analyses. Heat, flammable fluids, and complex electrical systems make these zones the most fire-prone in gasoline and diesel vehicles. EVs and hybrids have different patterns, but internal-combustion engine bays remain the leading origin overall. Vigilant maintenance, prompt attention to warning signs, and safe responses during an incident are the best ways to reduce risk and limit harm.

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. 

Where do most fires start in a car?

The most common item to initially ignite is insulation around the electrical wiring, or cables. Unsurprisingly, the second leading category of ‘items first ignited’ is liquids, piping, and filters, which include fuel in various locations throughout the vehicle.

Is true or false most vehicle fires start in the engine compartment?

True, most vehicle fires start in the engine compartment due to the heat generated by its components and the proximity of fuel and electrical systems. Mechanical failures, electrical malfunctions, and fuel leaks are common causes for these fires to ignite in this high-heat area. 
Reasons why fires start in the engine compartment:

• Heat and Fuel Proximity: Opens in new tabThe engine compartment contains numerous components that generate significant heat, making it a prime location for ignition if fuel or electrical systems leak or short circuit. 
• Mechanical Failures: Opens in new tabOverheating, oil leaks, and fluid leaks (like coolant) can create conditions ripe for fire. 
• Electrical System Failures: Opens in new tabFaulty wiring, short circuits, and issues with the battery or other electrical components can easily spark a fire in the engine bay. 
• Fuel System Issues: Opens in new tabLeaks from fuel lines or injection systems can release flammable vapors that are easily ignited by a heat source in the engine compartment. 

Where do vehicle fires generally start?

A spark from the crash could cause these fluids to catch fire. This includes brake fluid, fuel, engine oil, transmission fluid, and other fluids. Most fluid-related fires start under the hood, although some, such as those related to fuel and brake fluid, may occur at any point in the vehicle.