WE put in a stove and are now in our 3rd winter with it. It has really cut down on our use of Home Heating oil to approx 150ltrs/year. I reckon there's about 200ltrs left in our 1100ltr oil tank. With the price of oil now low I was thinking about filling it up but it could be 6/7 years before I need to fill it again. I was wondering if oil is ok in a tank for this length, does it lose anything or have a best before date like food?