We drove our 2008 Toyota Scion a total of 17,450.4 miles in the last year, burning 542.58 gallons of gas for an average of 32.2 miles per gallon. That's more miles than we drove it in either 2009 or 2010. Our average miles per gallon has been about the same since we first started driving the Scion in 2008.
Our best mileage of the year, 36.9 miles per gallon, was in early September, when I logged a day's worth of highway driving from Lewes to Villanova to pick up daughter #1 and then to Upper Marlboro, MD, for our nephew's wedding. Our worst, 29.5 mpg, was the last week of the year, when I was driving only short hops from home to my vanpool meeting spot.
We spent $1,878.72 on gasoline for the Scion in 2011. Gas prices we found averaged $3.50 over the year, with a low of $3.03 per gallon at the start of the year and a high of $3.94 in early May.
These metrics are for the period December 31, 2010 through mid-day today. They are from my gas mileage log, a Google spreadsheet. I also track gas mileage using Matt Haughey's fuelly.com.