How many gallons or liters of gas come from a barrel of oil?

Question

If a barrel cost $120 and it holds 55 gallons of oil which is about $2.18 cents per gallon. But oil is used also for other things like plastic, fuel and other by products. I drive a Smart Car and I am getting around 50 to 60 miles to gallon of diesel but then that engine is not sold in the USA. I drove from Montreal to New York city and it cost me only $45 round trip.

Answer 1

A standard barrel of oil is 42 gallons once refined, you get the following:

19.5 gallons of gas per barrel

9.2 of fuel oil(including diesel)

4.1 of jet fuel

and 9.2 of other products

this adds up to more than 44 gallons because of processing gains

Answer 2

A breakdown of what products we get from a barrel of crude (which is 42 gallons): http://www.eia.doe.gov/kids/energyfacts/...

It's a "kids page", but I use it all the time to describe the refining process.  

A breakdown of the price of gasoline, the info is a bit dated, crude has risen to about 65% of the total cost: http://www.eia.doe.gov/bookshelf/brochur...