What's in a barrel of oil?

Many things, and when all is said and done, the total volume is more than the original 42 gallons of crude:

Figures are based on 1995 average yields for U.S. refineries. One barrel contains 42 gallons of crude oil. The total volume of products made is 2.2 gallons greater than the original 42 gallons of crude oil. This represents "processing gain."

Another site explains "processing gain" as due to the addition of other chemicals during the refining process.

It's interesting to see what 4.2 grams of gold will get for you in an industrialized society! (HT: The younger of my brothers.)

-- CAV