44 Imperial Gallons x 4.546 = 200 liters
55 US Gallons x 3.785 = 208 liters
1 Imperial Gallon x 1.2 = 1.2 US Gallons
1 Barrel of Crude = 42 US Gallons, 35 Imperial Gallons or 159 liters.
https://www.aoghs.org/transportation...on-oil-barrel/
I'm not aware of Jet fuel being sold in "Barrels" (being the 42 US gallon "Tiece" equivalent), rather drums filled to either Imperial or US Gallons and clearly labelled with the content volume.