When my father bought the home place in the 70's he got a 600 gallon tank from an uncles place of his and filled it with red diesel. Twas red back then and I'm old enough to remember red diesel :sweat:. Anyhow the father often remarked that in those days it lasted him 3 years before needing a refill. Diesel going moldy was unheard of then. My granduncle used it to store petrol during WW ll and obviously he never put any of it in his car seeing as it was a lower tax class for agri use
. I'd say the same tank is made of 5mm steel and we still use it today and no doubt the next generation will also use it. I think it cost 30 quid to fill up. It's multiples of that now and for questionable quality fuel.