When we did weight and balance on the small piston engine aircraft I trained on we always used 9lb per U.S. gallon
The answer will depend on how much aviation oil.
6 pounds
8
DOW (Dry Operating Weight) in aviation refers to the weight of an aircraft when it is empty and without any fuel or payload. It includes the weight of the structure, systems, equipment, and furnishings of the aircraft. DOW is used to calculate the aircraft's performance, fuel calculations, and maximum payload capacity.
6 pounds per gallon
It they are the same weight oil as in SAE 30 weight oil there is no difference and they are identical. 30 weight oil is 30 weight oil synthetic or conventional.
weight of oil is lighter than water
Just the opposite, 30 weight oil is thinner that 40 weight oil and will flow better at low temperatures.
It is the weight of the multi-vicosity oil. The 10 is the weight of the oil when cold. The W stands for Winter. The 40 is the weight of the oil when it gets hot.
SAE 10 weight oil
10w30 weight oil.
It is brought to the surface and taken to an oil refinery where the different components are separated, like heating oil, diesel, gasoline, aviation fuel. These are different fractions of the crude oil from the well.