what is the difference between #1 and #2 fuel oil?
#1 fuel oil is more refined than #2 oil, has a lower pour point (or gel point or waxing point), is less viscous, has a higher septane rating and contains fewer BTU's per gallon than #2 heating oil. No. 1 fuel oil is quite similar to kerosene and is the fraction that boils off during oil, refining right after gasoline.