#2 Heating Oil vs. Kerosene vs. Diesel: What's the Difference?
From the Alcus family · Alcus Fuel Oil & Sons, Amityville · Updated October 31, 2026
People call it heating oil, fuel oil, #2 oil, home heating oil or "red diesel". Here's what's actually in your basement tank, how it compares with kerosene and diesel, and what's safe to use if you ever run short.
Side by side
| No. 2 heating oil | Kerosene (No. 1) | On-road diesel | |
|---|---|---|---|
| Used for | Home boilers and furnaces | Outdoor/attic tanks, space heaters, cold climates | Cars, trucks |
| Color | Dyed red (untaxed as road fuel) | Clear (or dyed) | Clear |
| Sulfur in NY | Ultra-low, 15 ppm max | Varies (ultra-low sulfur kerosene is sold) | Ultra-low, 15 ppm max |
| Cold weather | Can thicken or gel in an outdoor tank in deep cold | Resists gelling | Winter blends sold in cold months |
| Heat per gallon | About 138,500 BTU | About 135,000 BTU | About 137,000 BTU |
| Price per gallon | Usually less than kerosene or road diesel | Higher | Higher (road taxes) |
Heat contents are typical values from the U.S. Energy Information Administration. Exact numbers vary by blend.
What we deliver
We deliver No. 2 ultra-low sulfur heating oil, blended with biodiesel (Bioheat), dyed red as heating fuel. That's what nearly every Long Island home with a basement oil tank burns. For what's in it and why, see Bioheat and ultra-low sulfur heating oil. We don't sell kerosene or highway diesel.
Ran out? What you can use until we get there
- Call us first at 631-264-8800. Our 24/7 emergency line takes out-of-oil calls; our minimum delivery is small, so you may not need to buy fuel elsewhere at all. See ran out of heating oil.
- If you must: 5–10 gallons of clear diesel from a gas station, in proper fuel cans, poured into the outside fill pipe. Kerosene works too.
- Then reset carefully: press the burner reset button once. If it doesn't start, don't keep pressing it: repeated resets can flood the chamber with oil. Follow how to restart an oil burner after running out, or call for service.
Never use gasoline, motor oil, cooking oil or solvents. Gasoline vapors in an oil burner can explode.
Outdoor tanks and gelling
Heating oil can start to thicken in an above-ground outdoor tank or exposed line in a hard freeze, and the burner can starve even with oil in the tank. A technician can add a winter additive, insulate the line, or recommend a blend. If your burner stops on the coldest night of the year and the gauge isn't empty, mention that your tank is outside when you call. Indoor basement tanks rarely have this problem.
Need oil or service on the South Shore?
Questions
Is heating oil the same as diesel?
Very close. No. 2 heating oil and No. 2 diesel are both middle distillates, and in New York both are now ultra-low sulfur (15 ppm or less). The main differences are tax and dye: heating oil is dyed red because it is not taxed as highway fuel, and some diesel has additives for engines. Most heating oil sold on Long Island today, including ours, is also blended with biodiesel (Bioheat).
Can I put diesel in my oil tank if I run out?
In a pinch, yes: a few gallons of clear (on-road) diesel from a gas station can get an oil burner running until a delivery arrives. It costs more per gallon, and you should pour it in through the fill pipe outside, never into the tank opening in the basement. If the tank ran completely dry, the burner may still need a reset or the line bled.
Can I burn kerosene in my oil burner?
Most oil burners can burn kerosene, and some homes with outdoor or attic tanks use it because it resists gelling in the cold. It costs more per gallon and has a little less heat per gallon than No. 2 oil. Ask your service technician before you switch: the nozzle may need to change. We deliver No. 2 heating oil; we do not sell kerosene.
Can I use red (dyed) diesel in my truck?
No. Dyed fuel is untaxed for off-road and heating use only. Using it in a car or truck on public roads is illegal under federal and state tax law and carries heavy fines.
What should never go in a home oil tank?
Gasoline, motor oil, used cooking oil, paint thinner or anything else that isn’t heating oil, kerosene or diesel. Gasoline in particular can cause a fire or explosion in an oil burner.