I've read that due to changes in the molecular structure, the refineries actually get ~44 gallons of product from a 42 gallon barrel of oil. From that you get:
* 19.5 gallons of gasoline
* 9 gallons of fuel oil
* 4 gallons of jet fuel
* 11 gallons of other products

link: http://www.gravmag.com/oil.html#dollar

I've also read that the retail value of a refined barrel of oil is worth >$1000 mainly from the sale of the 'other products'. In other words, the revenue from the gasoline and other fuel oils is a drop in the bucket compared to the other products. However, I have not been able to find any hard data on this info. Anyone, anyone?