One can approximate the swelling or shrinkage of lube oils by using the correct ratio of the density at two temperatures (see table above), or use the thermal coefficient of expansion discussed here.

Oils with an API Gravity 15 to 34.9 should use coefficient of expansion of 0.0004 per degree F at 60.  Oils with an API gravity of 35 to 50.9 should use 0.0005 per degree F at 60F.

Example 1.  The lubricant API gravity is 30, and 1000 gallons was placed in a truck at 180 °F.  What is the volume after the oil cools to 60 F? 

The volume correction is:

            1.0000 - 0.0004 (180 F – 60 F)   =   0.9520.   Hence 0.9520 x 1000 gallons = 952 gallons.