How many kilograms in 1 Gallon of oil?

Texas Crude Oil Density = 873 kg / cubic meter

1 cubic meter = 264.172 gallons

1 barrel of oil = 42 gallons

42 gallons * (1 cubic meter / 264.172 gallons) = .15898 cubic meters / barrel

.15808 cubic meters / barrel * (873 kg /cubic meter) = 138.8 kg / barrel of oil