rounding off all numbers for brevity: 42 gallons of crude - 50% becomes gas =21 gallons gas.
60 bucks a barrel is 60 bucks for 21 gallons at 2.75 a gallon, well that means that the other 50% of that barrel isn't accounted for, or, 1/2 of every barrel becomes pure profit for the refinery company. That doesn't seem unreasonable... I think.