A 55 gallon drum of oil weighs 444lbs.
A 55 gallon drum of water weighs slightly more than the 55 gallon drum of oil as the 55 gallon drum of water weighs around 484lbs.
A 42 gallon drum of oil weighs around 300 lbs.
A standard-size barrel holds 42 U.S.gallons.
If one fills a standard sized barrel with petroleum oil that has a density of 881 kg/m3, then that barrel weighs about 300 pounds.
If one fills the same barrel with crude oil with a density of 790 kg/m3, that barrel weighs about 275 pounds.
The volume of a barrel of oil is quite specific and equal to about 35 imperial gallons (42 US gallons, about 159 liters).
A barrel of oil is also significantly heavy.
Since average domestic crude oil weighs about 7.21 pounds per gallon, a barrel of oil weighs around 300 pounds or about 136 kilograms.
The density of water(1000 kg/m3) is higher than the density of oil(870 kg/m3).
According to the mathematical equation, mass =density*volume. Now keeping the same volume for both water and oil the mass would be greater for water. Hence the water is heavier than oil.