A gallon is a unit of capacity. An ounce is a unit of mass. Without some unit of density to compare, the two units are incompatible.
A pinch
20 gallons = 2,560 ounces.
13.2 gallons is 1,689.6 ounces.
8320 ounces is 65 gallons.
169 ounces is 1.32 US gallons.
63 US gallons is 8,064 ounces.
5.22 fluid ounces is 0.04 gallons.
Eleven US gallons is 1,408 ounces.
24 US gallons is 3,072 ounces.
211 fluid ounces is 1.648 gallons.
15,360 fluid ounces is 120 gallons.
15 US gallons = 1,920 ounces.