Liquid Specific Gravities

Oil water separator sizing depends on the difference between the specific gravity of the oil and that of water: the lighter the oil, the faster its droplets rise. Use these typical values as a starting point; your own product data sheets or a lab test give the exact value.

Liquid	Specific gravity
Base oils
5W	.862
10W	.875
20W	.881
40W	.892
50W	.894
10W-30	.893
Blended oils
10W	.863
50W	.911
Crude	.78 – .91
Fuels
Fuel oil #2	.81 – .92
Fuel oil #3	.82 – .95
Fuel oil #4	.88 – .97
Fuel oil #5A (Bunker A)	.91 – .99
Fuel oil #5B (Bunker B)	.91 – .99
Fuel oil #6 (Bunker C, low sulfur)	.91 – 1.06
Fuel oil #6 (Bunker D, high sulfur)	.93 – 1.07
#2 diesel fuel oil	.82 – .95
Navy #2	1.0
JP4 – JP8	.74 – .85
Kerosene	.78 – .82
Gasoline	.68 – .74
Transmission fluids
Dextron ATF	.88
ATF type F	.88
Type C2	.88
Marine propulsion & power turbines
Light – heavy	.87 – .89
Machine & industrial oils
SAE 75, 80, 90, 140, 250	.93
VOCs and other compounds
Benzene	.87
Cumene	.86
Ethylbenzene	.87
Trichloroethylene (TCE)	1.47
Perchloroethylene (PCE)	1.62
Toluene	.86
Xylene	.88
Methyl ethyl ketone (MEK)	.80
Naphtha	.76
Creosote	1.05
Pentachlorophenol (PCP)	.96
Naphthalene	1.14
Bunker C	.91 – 1.06
Bunker D	.93 – 1.07
Miscellaneous oils
Mineral oil	.875
Castor	.96
Corn	.92
Coconut	.92
Cottonseed	.93
Cod liver	.92
Glycerin	1.26
Lard	.90 – .92
Linseed	.93
Turpentine	.86 – .87
Olive	.91 – .92
Palm	.92
Peanut	.92
Rapeseed	.92
Sesame	.92
Soybean	.92 – .98
Miscellaneous products
Propylene glycol	1.036
Water	1.0

Typical values from Pan America Environmental's engineering resources. Liquids heavier than water (specific gravity above 1.0) sink rather than float.