GasBuddy.com, which tracks gas prices nationwide, recently released a state-by-state analysis of what day of the week offers the lowest price for gasoline, on average. Here are its findings for Illinois for the last four years:
2013 — Saturday
2012 — Friday
2011 — Monday
2010 — Sunday
GasBuddy's conclusion: Best time to fill up in Illinois is generally the weekend.
If you head east to Indiana, it's a better bet to fill up on Mondays. Indiana prices, on average, were lowest on Monday each of the past four years.
GasBuddy found that 65 percent of states saw lower prices on the weekend — Friday, Saturday or Sunday — than during the week. Very few states saw Tuesday or Wednesday as the best day to fuel up.