We go thru about a gallon a month...........
And if you were to convert this to diesel, you'd get what, an extra 3/4 gallon of biodiesel which is about 1/2 gallon of gasoline energy equivalence? Not to mention the cost of the catalysts, equipment, your time.
Making biodiesel with cooking oil waste is a perfectly fine hobbyist pursuit but there's no scale in it.
And how much motor fuel do you use in the same time period?