You can only fill the tank to 80%. So that number is not accurate. Should be about 140 gallons.
It should take 240 gallons to fill it up. 500 x .48 = 240
500 gal/ 100%=5 gal/1%x52%=260 gal subtracted from 500 gal ttl=240 gal needed to fill completely...
Too easy....
Too easy....