Where Most Vehicle Fires Start

Most vehicle fires start in the engine compartment—specifically the engine, running gear, or wheel area—according to repeated analyses by U.S. fire-safety agencies such as the National Fire Protection Association (NFPA). These areas combine combustible fluids, high heat, and complex electrical systems, making them the most common origin points for highway vehicle fires. Below, we explain what the data show, why these zones are most vulnerable, and how drivers can reduce risk.

What the data show

Fire incident data collected over many years indicate that a majority of highway vehicle fires originate in and around the engine bay, running gear, or wheel assemblies. Mechanical failure or malfunction and electrical issues are the leading factors, with fuel and lubricant leaks, overheated components, and wiring faults frequently involved. While fires can begin elsewhere—such as the passenger compartment or cargo area—these account for a smaller share.

Why the engine bay is the hotspot

The engine compartment concentrates multiple ignition risks in a tight space. The following factors commonly align to make it the most likely origin of a vehicle fire:

• Fuel and oil leaks contacting hot surfaces like exhaust manifolds or turbo housings
• Electrical shorts or chafed wiring harnesses producing sparks or heat
• Overheating due to cooling-system failures, low coolant, or stuck thermostats
• Exhaust system and catalytic converter temperatures igniting nearby materials
• Brake and wheel-bearing overheating that can spread heat to the wheel well
• Accumulated debris (leaves, plastic bags) in the engine bay or undercarriage igniting on hot components

Because these hazards can occur simultaneously—especially in older or poorly maintained vehicles—the engine area remains the predominant origin point for fire incidents on the road.

Other common origins (but less frequent)

While the engine and running gear dominate fire origins, several other areas occasionally serve as ignition points, depending on vehicle type, usage, and incident circumstances:

• Passenger cabin: Smoking materials, aftermarket electronics, or heater/blower faults
• Cargo/trunk area: Improperly stored flammables, batteries, or powered equipment
• Undercarriage: Catalytic converter igniting road debris or dry vegetation
• Electric/hybrid battery pack: Thermal runaway from damaged cells, usually after severe impact or charging faults (overall incidence remains low relative to fleet size)
• Deliberate ignition (arson): Intentional fires, more often when vehicles are parked

These origins underscore that while any part of a vehicle can be involved under the right conditions, routine heat, fluids, and electrics in the engine and running gear explain the majority of starts.

How to reduce the risk

Proactive maintenance and safe operating practices markedly cut the odds of a vehicle fire. Consider the following prevention measures:

• Fix fluid leaks promptly; replace cracked hoses, worn gaskets, and brittle fuel lines
• Address electrical warnings; repair frayed wires and avoid oversized fuses or DIY bypasses
• Keep the engine bay clean; remove leaves and debris that can contact hot parts
• Watch temperature and oil-pressure gauges; pull over if overheating or smoke appears
• Service brakes and wheel bearings; overheating here can spark wheel-well fires
• Check for safety recalls; have recall repairs completed without delay
• Use certified installers for aftermarket electronics and remote starters
• Avoid parking over dry grass; catalytic converters can ignite vegetation
• Carry a small, automotive-rated fire extinguisher if permitted and know how to use it

These steps target the typical ignition pathways in the engine and running gear, where prevention has the biggest payoff.

What to do if you suspect a fire

If you smell burning, see smoke, or notice warning lights and heat spikes, act quickly and safely using the steps below:

1. Signal, pull over to a safe area, and stop the vehicle; shift to park and turn off the engine
2. Evacuate everyone immediately and move at least 100 feet upwind from the vehicle
3. Call emergency services; do not reopen the hood fully—introducing air can intensify flames
4. Use a fire extinguisher only if the fire is small, you’re trained, and you can stay at a safe distance
5. Do not attempt to retrieve belongings; wait for firefighters and keep others away

Rapid, calm action reduces risk of injury and prevents a smoldering problem in the engine bay from becoming a fully involved fire.

Summary

Most vehicle fires start in the engine compartment, encompassing the engine, running gear, and wheel area, where heat, combustible fluids, and electrical systems converge. Mechanical and electrical failures—often compounded by leaks or debris—are the leading contributors. Good maintenance, prompt repairs, and safe operating habits are the most effective defenses against these common fire origins.

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.

Do most vehicle fires start in the engine compartment?

Most vehicle fires do start in the engine compartment. The engine compartment of a vehicle contains various components that can generate heat, such as the engine itself, the exhaust system, and the electrical wiring. If there is a fuel leak or a malfunction in any of these components, a fire can easily ignite.

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.

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.