There might be ten gallons of unusable fuel left in the tank when you can no longer suck fuel.

Mine is also a Florida Marine Tank with the plate on it but got a slightly smaller capacity . . . 57 US GAL engraved on the plate.

i will go have a look for a plate on tip then thanks

ok i am going say something a bift daft again i am asure but why would you still have 10 gallon in it when you have drained it ?

my plate says 70 but can only fill to 60 on trailer

so appx how many hours running time can you get gallons per hour or appx MPG if hooning it and then if you are cruising to go somewhere.
i actually have no idea what cruise speed might be 40mph ?
i am trying to get an idea or range as the boat will leave the UK and head out to the Balearic islands to live. i want an idea as to what islands i could hop and can i reach the mainland without towing a tanker behind me.
anything ideas in the ball park will help. i appreciate that i am asking the unanswerable.

Let me get this straight . You restored a 79 Pantera to leave the mainland and go live on an island ? Is there senoritas and margaritas involved ? If so I want your life ....

I agree! Not sure if this is accurate since I've never calculated mine but I recall reading that something similar to this size would get around 2 to 2.5 miles per gallon. I hope there's fuel on that island because otherwise you need to factor in having enough to get you back

sadly yes loads. it will be tappas and tango for the rest of my days i think

and 1 gallon in the UK = 1.2009499255049 gallon in the USA

ah ok that's nice and simple then as equates to 3m to a UK gallon so a little of 6 miles to 10 litres.
so i have an appx range of about 180 miles on that basis.
From the island of mallorca to get to Ibiza is about 120 miles so thats pretty neat then.