The average price of a gallon of gas in 2005 stood at $2.30 in current dollars and $2.66 in constant dollars as of 2015, according to Energy.gov. Constant dollars represent the value of money from one time period compared to today?s dollar value.
The figures show how much a gallon of gasoline costs in today?s dollars compared to the actual value in 2005. Therefore, a gallon of gas at $2.30 in 2005 would cost $2.66 in 2015, adjusted for inflation. Current prices, also known as nominal prices, represent the face value of any products, goods or services bought and sold on the open market.