Why Kerosene Isn’t Used in Cars

Kerosene isn’t used in cars because it doesn’t vaporize or ignite properly in gasoline engines, would cause hard starting, misfires and knocking, can damage emissions equipment, and in diesel engines it lacks the lubricity and additive package needed to protect modern fuel systems. While kerosene works well in jet turbines and some heaters, passenger vehicles are engineered for gasoline or diesel and their tightly regulated emissions standards—fuels kerosene doesn’t meet.

How Car Engines Are Designed to Burn Fuel

Modern cars use either spark-ignition (gasoline) or compression-ignition (diesel) engines. Gasoline engines rely on a fuel that vaporizes easily and resists self-ignition (high octane), so a spark can precisely ignite a well-mixed air-fuel vapor. Diesel engines compress air until it’s hot enough that injected fuel ignites on its own (requiring good autoignition quality—high cetane—and proper lubricity to protect high-pressure pumps and injectors). Kerosene sits between gasoline and diesel in distillation range but matches neither set of requirements closely enough for today’s cars.

What Makes Kerosene a Poor Fit for Gasoline Cars

Volatility and Ignition

Kerosene is a heavier, less volatile fuel with a much higher flash point (roughly 38–72°C) than gasoline (around −43°C). Gasoline vaporizes easily at ambient temperatures, enabling a combustible mixture for spark ignition and cold starts. Kerosene does not, so it tends to puddle in intake tracts, causes hard starting and stalling, and leads to incomplete combustion and deposits. If sufficiently heated to vaporize, kerosene’s very low octane rating makes it prone to severe knock in a spark-ignition engine.

Fuel System and Atomization

Kerosene is more viscous than gasoline, upsetting spray patterns and atomization in carburetors and injectors designed for gasoline. Poor atomization worsens mixture control and combustion stability, raising soot formation and fouling spark plugs, valves, and intake components.

Emissions Equipment Compatibility

Road gasoline is formulated to ultra-low sulfur limits (about 10 ppm in the U.S. and EU), plus detergents to keep intake systems clean. Common kerosene grades (e.g., heating kerosene or Jet A/A-1) can contain far more sulfur (Jet A-1 specification allows up to 0.30% by mass, i.e., up to 3,000 ppm), ash, and different aromatics—levels that can poison oxygen sensors, destroy three-way catalytic converters, and overload gasoline particulate filters with soot. Even if an engine runs, it won’t meet emissions regulations.

Energy Content Isn’t the Bottleneck

On a per-liter basis, kerosene’s energy content is similar to gasoline (around 34–35 MJ/L), so range isn’t the main problem. The limiting factors are ignition behavior, volatility, and compatibility with engine hardware and emissions systems.

What Happens If You Try It in a Gasoline Car

The following points summarize the practical issues a driver would experience if kerosene were used in a gasoline vehicle, even in small proportions.

• Hard starting, rough idle, and frequent stalling due to poor vaporization.
• Severe knocking under load if the fuel gets hot enough to vaporize, risking piston and bearing damage.
• Heavy soot and deposits that foul spark plugs and intake valves, degrading performance quickly.
• Rapid damage to oxygen sensors and catalytic converters from sulfur and ash, triggering check-engine lights and costly repairs.
• Poor drivability and fuel metering errors because injectors are not calibrated for kerosene’s viscosity and spray behavior.

Taken together, these issues mean a gasoline engine will run badly, if at all, and suffer expensive long-term damage.

What About Diesel Cars?

Diesel engines are closer to kerosene in principle, but modern road diesels still aren’t designed for straight kerosene. Ultra-low-sulfur diesel includes additives for lubricity, detergency, cetane quality, and aftertreatment compatibility. Kerosene (and aviation kerosene/Jet A) typically has lower lubricity and different additive profiles, risking wear in high-pressure fuel pumps and injectors. Power output also drops because of lower density compared to diesel, and emissions systems (DPF and NOx controls) can be stressed or damaged.

Limited, Specific Exceptions

In very cold climates, regulated “No. 1 diesel” or winter diesel blends include a controlled proportion of kerosene to improve cold flow, but they also contain lubricity improvers and are sold as on-road-compliant fuels. Some fleets and military applications use jet fuel in diesel engines with tailored maintenance, additives, and calibrations. These are managed exceptions—not general guidance for consumer vehicles.

Legal and Regulatory Factors

On-road fuels are tightly regulated for emissions and taxation. Heating kerosene is dyed and untaxed in many countries; using it on-road is illegal and detectable. Even if an engine could be made to run on kerosene, the vehicle would likely fail emissions certification and violate fuel-use laws, voiding warranties and insurance.

Where Kerosene Does Belong

Kerosene is ideal for gas turbines (jet aircraft) and some heaters because its higher flash point improves handling safety and its combustion characteristics suit continuous-combustion engines. Those systems are engineered around kerosene’s properties and emissions profiles—cars are not.

Could a Car Be Designed for Kerosene?

In theory, yes—but it would look a lot like a modern diesel with specific adjustments for kerosene. Here’s what that would entail.

• A compression-ignition engine calibrated for kerosene’s ignition delay and combustion speed.
• High-pressure injection hardware compatible with kerosene’s lubricity, plus lubricity-enhancing additives.
• Fuel heating and tailored injectors/nozzles to ensure fine atomization and clean burn.
• Aftertreatment (DPF/NOx systems) validated for the fuel’s sulfur/aromatic content or a guaranteed low-sulfur kerosene supply.
• Regulatory certification as an on-road fuel with appropriate taxation, distribution, and quality control.

This adds complexity and cost without clear benefits over existing diesel technology, which already optimizes similar combustion with a purpose-designed fuel.

Summary

Kerosene isn’t used in cars because it’s incompatible with how gasoline engines vaporize and ignite fuel and how their emissions systems are protected, and it lacks the lubricity and additive package required by modern diesels. While kerosene excels in turbines and can be part of specialized diesel blends under strict control, it’s neither a drop-in substitute nor a legal on-road fuel for passenger vehicles.

Why can’t we use kerosene in vehicles?

• Engine Damage: Kerosene has a different combustion properties compared to gasoline, which can lead to incomplete combustion, knocking, or even damage to engine components.
• Fuel System Issues: Kerosene can clog fuel filters and injectors, leading to poor engine performance or failure to start.

Can a gasoline engine run on kerosene?

Putting kerosene in a gasoline engine is harmful because kerosene is a heavier, less volatile fuel that won’t atomize properly in a gas engine’s carburetor, leading to incomplete combustion and a poor-running, smoky engine. While a small amount might go unnoticed, a larger quantity will cause rough operation and may require fuel system repairs, potentially damaging the engine or its components.
 
Why kerosene is bad for a gasoline engine

• Improper vaporization: Opens in new tabKerosene has a higher boiling point and doesn’t vaporize easily in a low-temperature, low-compression gasoline engine. 
• Incomplete combustion: Opens in new tabThe unburned kerosene leaves behind “heavy ends” in the combustion chamber, which can cause pre-ignition and knocking. 
• Carbon buildup: Opens in new tabThe unburned fuel can lead to excessive carbon deposits, causing the engine to run poorly. 
• Carburetor damage: Opens in new tabKerosene can swell or damage rubber components in a carburetor, potentially requiring overhaul or replacement. 
• Engine damage: Opens in new tabIn severe cases, the uncontrolled pressure from pre-ignition can cause significant internal damage to the engine. 

What to do if you accidentally use kerosene

1. Stop the engine: Turn off the engine immediately if you notice it running rough. 
2. Drain the fuel system: Remove the fuel from the tank, lines, and carburetor. 
3. Clean the components: Clean any affected carburetor parts to prevent further damage from leftover fuel. 
4. Refill with proper fuel: Replace the drained fuel with the correct grade of gasoline. 
5. Seek professional help: If the engine runs poorly or exhibits strange behavior, consult a mechanic for a thorough inspection. 

Why is kerosene used instead of gasoline?

Storing large amounts of kerosene is relatively safe compared to gasoline or propane, as it is less volatile and does not easily ignite. In conclusion, kerosene is an excellent choice for off-grid living and emergencies, providing a dependable and affordable source of energy for cooking, lighting, and heating.

Did cars ever run on kerosene?

In Europe following the Second World War, automobiles were similarly modified to run on kerosene rather than gasoline, which they would have to import and pay heavy taxes on.