(Undated) – The national average for a gallon of regular unleaded remains largely unchanged from Monday. According to this morning’s numbers from GasBuddy.com, the national average is $3.19 a gallon. However, here in Illinois, the statewide average has fallen three cents from Monday to $3.45 a gallon. Across the river in Indiana, the statewide average is $3.15 a gallon, down eight cents from Monday. Several states are enjoying averages below three dollars a gallon with Mississippi leading the way with an average of $2.62, down two cents from Monday. California has the highest price at $4.62 a gallon, down four cents from Monday.