Welcome back to the grind The national average gas price has gone up 0.9¢ since last week to $2.538 - this time last year it was $2.310 so it's 9.9% (+22.8¢) dearer. Diesel is has climbed 1.4¢ to $2.944. It's now 14.9% (+42.1¢) more expensive than this time last year. Diesel is a 16% premium to regular. E85's average price is down from $2.100 to $2.078 - a year ago it was $1.983.