The website of the U.S. Energy Information Administration publishes a weekly article that shares the latest prices of a barrel of gasoline at EIA.gov. Bloomberg.com posts regular updates of the per barrel price of gasoline inside and outside of the United States.
Apart from publishing the current price of a barrel of gasoline, the Energy Information Administration publishes a graph and related statistics comparing the current price to prices in recent history. A small table in each edition of its "This Week in Petroleum" shows the difference between the current price and the price of both one week ago and one year ago down to the nearest cent. An accompanying graphic plots the current per barrel price of gasoline on a line graph with the past year of weekly per barrel prices beside it. For added context on the same graph, a separate segmented line plots data points charting weekly prices from two years ago up to one year ago.
"This Week in Petroleum" explores the recent market activity and price fluctuations of gasoline, as well as Brent crude oil, diesel fuel, heating oils, distillate and propane. Here, the EIA documents how recent energy-related news stories such oil spills, international conflicts and the tapping of new sources of energy can cause fluctuations in the market. The "Past Weeks in Petroleum" link opens an archive of the energy market dating back to 2002.