The national average price of gas increased 6.1 cents to $3.143. The national average is up 1.9 cents from a month ago and down -41.0 cents from a year ago. The national average price of diesel has increased 2.9 cents in the last week and stands at $3.502 per gallon. The median US gas price is $2.99 per gallon, up 8 cents from last week and about -15 cents lower than the national average.