This information is from various sources. I tried to find at least two, and possibly three independent sources for each of these facts. Some of them have a tolerance due to the nature of the material. I do not know what those tolerances are.
Wherever possible I cross referenced with the Energy Information Administration

A British Thermal Unit (BTU) is the amount of heat energy needed to raise the temperature of one pound of water by one degree F. This is the standard measurement used to state the amount of energy that a fuel has as well as the amount of output of any heat generating device. A BTU or KWH is a measure of energy. A watt or Horsepower is a measure of work done. (IE: Work done, watts, over a period of time, hours, equals an amount of energy: KWH) 
A watt is the basic unit of electric, mechanical, or thermal power in the SI and MKS systems.
One watt is the rate at which work is done when an object is moving at one meter per second against a force of one newton. 
In the units of ampere and volt, work is done at a rate of one watt when one ampere flows through a potential difference of one volt. Equal to one voltampere. For electric power: A Watt is the fundamental unit of electrical power, and is a rate unit, rather than a quantity.The wattage is determined by multiplying the voltage (E), as measured in volts (V), by the current (I), as measured in amperes (A). 
This data is from a 2005 US Senate Investigate comittee report.
http://www.senate.gov/~gov_affairs/042902gasreport/sectioniii.pdf
This country has about 240 Million vehicles, and About 167,000 Gas Stations.
The average gas station sells 75,000  100,000 Gallons a Month.
Over 70 percent of Gasoline sales are at Convienence stores, for a total of $344 Billion in 2005
Branded Gas stations sold 52% of all gasoline in 2005
'Hypermarkets'  supermarkets, discount retailers and warehouse clubs Sold 11%
The average Gas Station makes 615 cents per gallon profit  Before credit card fees.
The US (4% of global population):
Used 98 quadrillion Btus of energy in 2003
39 quadrillion Btus of petroleum
23 quadrillion Btus of natural gas
23 quadrillion Btus of coal
8 quadrillion Btus of nuclear energy and
6 quadrillion Btus of renewable energy.
One quadrillion Btu is equal to 172 million barrels of crude oil