First, you must convert your heater into a waste oil furnace. It is not as hard as you might think, given the number of Internet outlets. Once you’ve finished, you can work out an arrangement to purchase waste oil from local auto dealerships or repair shops. They will probably work with you on price.
The amount you will save fluctuates daily, but you may easily save 50 cents or more per gallon for used oil. From the start, you’re saving 50 cents per gallon. If you build a clean burning system, which is readily available, you may even save more. These systems will use almost any type of recycled oil or hydrocarbon. Many shops use these systems now; they are already saving.