You don't need kerosene. The only reason the oil company tells you that is because it is an outside tank, I'm assuming, and kerosene won't gel up when it gets cold. What they won't tell you is, you don't need kerosene. That's right. Shocker. You can use regular home heating oil and just add a bottle of diesel fuel anti-gel in your tank to keep it from gelling up. Did this for twenty years, never a problem.