hope this is the right place to post this. not really an engine question. how much fuel should i leave in the tank when winterizing? i'm in pittsburgh and we usually see temps in the 10's or 20's. it will be stored outdoors but winterized by a local marine shop. its a 75 gallon tank. i ask now cause next time on the boat i will likely be putting fuel in but don't want to fill it up if i should be storing it empty