Here's the average price of gas in the U.S., in current dollars (blue), and its price adjusted for inflation (red). The real price peaked on 7/17/2008 at $4.30/gal (in current dollars).
(Click to enlarge.)I wonder what its price would be today if there had been no financial crisis....
Gas price: This Week in Petroleum, EIA
Inflation: CPI, Bureau of Labor Statistics