In recent decades, automobile manufacturers have made significant advances toward improving the overall energy efficiency of most passenger vehicles. At the same time, Americans continue to purchase larger, less fuel-efficient vehicles. Because of this trend, the average fuel efficiency of new vehicles has changed little over the past 20 years—about 24 miles per gallon.

In addition, motorists are driving more. According to the latest statistics from the U.S. Department of Transportation, Americans drive an average of 29 miles a day and spend some 55 minutes of every day in their vehicles. The average vehicle is driven about 12,000 miles per year, and annual per-vehicle gasoline use is approximately 550 gallons.

Transportation continues to be a major sector of the U.S. economy and is a critical factor in our quality of life.

According to the DOT, personal gasoline consumption breaks down like this: