Are Diesel and Kerosene the Same Thing?

No. Diesel and kerosene are both petroleum “middle-distillate” fuels, but they are not the same: they come from different cuts in the refining process, have distinct physical properties and safety profiles, and are formulated for different engines and appliances. In practice, they’re used differently—diesel in compression-ignition engines, kerosene in heaters, lamps, and kerosene-grade jet fuels—and they are only interchangeable in limited, manufacturer-approved situations.

What They Are

Refining and Composition

Both fuels are distilled from crude oil, but kerosene is a lighter cut than most on-road diesel. Kerosene typically comprises hydrocarbons with roughly 9–16 carbon atoms and boils around 150–300°C. Modern on-road diesel (ULSD, ultra-low sulfur diesel) skews heavier—about C10–C22—with a boiling range around 180–360°C. Because of these differences, diesel is denser and more viscous, while kerosene is thinner and better at cold-weather flow but offers less lubricity.

Typical Uses

The following list outlines common applications for each fuel to clarify where they are intended to be used and why those uses differ.

• Diesel: compression-ignition road vehicles (trucks, buses, cars), agricultural and construction equipment, generators, marine diesels; standardized as ASTM D975 (e.g., No. 2-D S15 for most road use in the U.S.).
• Kerosene (also called paraffin in the UK): space heaters and portable heaters (especially 1-K grade), lamps, camp stoves, and as the base for kerosene-grade jet fuels (Jet A/Jet A-1); heating kerosene is often standardized as ASTM D3699.
• Jet fuel: civil turbine fuel is a highly controlled kerosene fraction (Jet A in the U.S., Jet A-1 internationally) meeting aviation standards (ASTM D1655), not diesel.
• Heating oil: No. 2 heating oil is chemically similar to No. 2 diesel but formulated and taxed differently; kerosene is sometimes used for indoor heaters because it burns cleaner in wick appliances when properly refined (1-K).

In short, diesel is engineered for high-pressure injection and lubrication in engines, while kerosene is lighter, cleaner in simple burners, and tailored for heaters and turbines.

Key Differences at a Glance

These points summarize the technical distinctions that cause diesel and kerosene to behave differently in engines and heaters, and to be regulated under different standards.

• Cut and composition: Kerosene is a lighter distillate (roughly C9–C16); diesel is heavier (roughly C10–C22).
• Viscosity and lubricity: Diesel is more viscous and provides higher lubricity for fuel pumps and injectors; kerosene is thinner and typically lacks sufficient lubricity for modern diesel injection systems without additives.
• Energy content (by volume): Diesel generally has slightly higher energy per gallon (about 128,000 BTU/gal) than kerosene (about 124,000–125,000 BTU/gal), depending on exact formulation and temperature.
• Cold-flow behavior: Kerosene stays fluid at lower temperatures and is sometimes blended into diesel in winter to reduce gelling and improve cold starts.
• Flash point: Diesel typically has a higher flash point (about ≥52°C/126°F) than kerosene (about ≥38°C/100°F), making diesel somewhat less flammable in handling.
• Combustion metrics: Diesel fuels are rated by cetane number for compression ignition (often ~40–55); kerosene and jet fuels are governed by smoke point, freeze point, and other turbine-combustion specs rather than cetane.
• Sulfur and standards: U.S. on-road diesel is ULSD at ≤15 ppm sulfur (ASTM D975). Kerosene grades (ASTM D3699) vary; 1-K is lower in sulfur and contaminants than 2-K for cleaner indoor burning, but typical sulfur limits are higher than ULSD unless specifically desulfurized.
• Regulatory/tax treatment: On-road diesel is clear; untaxed off-road diesel is dyed red in many countries (including the U.S.). Kerosene may be sold undyed or taxed differently depending on use and jurisdiction.
• Intended equipment: Diesel for compression-ignition engines; kerosene for wick/pressure heaters, lamps, and turbine engines (Jet A/Jet A-1)—each fuel matches the requirements of its equipment.

Taken together, these differences explain why the fuels are not interchangeable in most cases without consequences for performance, safety, emissions, or equipment life.

Can They Be Used Interchangeably?

In Diesel Engines

Manufacturers generally do not approve running straight kerosene in modern diesel engines because kerosene’s low lubricity can damage high-pressure pumps and injectors. In very cold climates, controlled blending with kerosene or use of No. 1-D ULSD is sometimes permitted to improve cold-flow properties—but only with the engine maker’s guidance and often with added lubricity/cetane improvers. Always follow the owner’s manual, local fuel specs, and emissions requirements; tax-dyed fuels may also be illegal for on-road use.

In Heaters, Lamps, and Stoves

Unvented indoor heaters and wick lamps are designed for 1-K kerosene because it burns cleaner and with less odor than heavier fuels. Using diesel (or No. 2 heating oil) in devices made for kerosene typically produces smoke, soot, and odors, can clog wicks or nozzles, and may raise carbon monoxide risk. Only use the fuel grade the appliance specifies.

Aviation and Turbines

Commercial jet engines use kerosene-based jet fuel (Jet A/Jet A-1), not automotive diesel. Certified aircraft must use approved aviation fuels meeting strict standards; substituting road diesel is not permitted. Some industrial gas turbines can run on a range of fuels under controlled conditions, but that is equipment-specific and outside consumer use.

Safety and Storage

Handling and storing these fuels safely requires attention to their flammability, ventilation needs, and the materials compatible with each fuel.

• Flammability: Kerosene has a lower flash point than diesel, so keep it away from ignition sources and store in approved containers.
• Ventilation: Burn kerosene only in appliances designed for it, with adequate ventilation; follow manufacturer instructions to prevent CO buildup.
• Additives and labeling: If blending kerosene into diesel for winter, use proper additives for lubricity and clearly label containers to avoid misfueling.
• Shelf life: Both fuels can degrade; use clean, sealed containers, consider stabilizers, and rotate stock. Microbial growth can occur in diesel; keep water out of tanks.

Observing these precautions minimizes fire, health, and equipment risks, especially in enclosed spaces and cold-weather operations.

Bottom Line

Diesel and kerosene are related but distinct fuels. Diesel is heavier, higher in lubricity, and purpose-built for compression-ignition engines; kerosene is lighter, better in simple burners and turbines, and flows more readily in cold conditions. They are not the same and should only be interchanged where explicitly allowed by equipment manufacturers and fuel standards.

Summary

Diesel and kerosene come from different refining cuts and serve different roles. Diesel (ASTM D975, ULSD ≤15 ppm sulfur) powers compression-ignition engines and provides essential lubricity; kerosene (ASTM D3699) is a lighter fuel used in heaters, lamps, and as the basis for jet fuel. Key differences include viscosity, flash point, energy content, and regulatory standards. Limited kerosene blending into diesel may be acceptable in winter with proper additives and manufacturer approval, but straight substitution in engines or heaters is not advised. Use the fuel your equipment specifies for safety, performance, and compliance.

Can a diesel vehicle run on kerosene?

Kerosene will burn fine in most diesel engines without harming them. In fact, many newer diesel engines list kerosene as an approved fuel. Do not use kerosene in your diesel engine unless your owner’s manual lists it as an approved fuel or you have checked with the manufacturer!

Can I put diesel in a kerosene tank?

Yes, you can put diesel fuel in your oil tank as a temporary heating oil substitute. Diesel fuel and home heating oil are not the same, but you can substitute diesel for heating oil while waiting for your oil supply delivery.

What is another name for kerosene?

paraffin
Also known as paraffin, kerosene has other uses, including powering jet engines, the outboard motors of small boats, and in parts of Asia, motorcycles as well.

Are kerosene and diesel the same?

No, kerosene and diesel are not the same; while similar and sometimes used interchangeably (especially for #1 diesel, which is often synonymous with kerosene), they are distinct fuels derived from crude oil with different properties, refining levels, and applications. Kerosene is a lighter, more refined fuel used in heating and as Jet-A fuel, whereas traditional diesel (#2 diesel) is heavier, has a higher energy content, and is primarily used in vehicles and off-road equipment. 
Key Differences

• Refinement and Purity: Kerosene is a more highly refined product, containing fewer impurities than typical diesel fuel. 
• Weight and Density: Kerosene is a lighter fuel with lower density and a lower boiling point than #2 diesel fuel. 
• Energy Content: Kerosene has a slightly lower energy content (BTUs) per gallon compared to #2 diesel. 
• Viscosity and Cold Weather Performance: Kerosene has a thinner viscosity and better performance in cold temperatures because it doesn’t thicken or “gel” as easily as diesel under freezing conditions. 
• Applications:
  • Kerosene: Historically used for indoor lighting and heating; also serves as a basis for Jet-A fuel and is used in specialized heating applications. 
  • Diesel: Primarily used for diesel engines in trucks, generators, and other off-road equipment, as well as in the automotive sector. 
• Fuel Grades: “Diesel #1” is very similar to kerosene and is sometimes called #1 diesel, while standard “diesel” is often #2 diesel fuel oil. 
• Additives and Dyes: Fuels are dyed for tax purposes; for example, heating oil (a type of kerosene) is often dyed red to distinguish it from on-road diesel, which is more heavily taxed.