After weeks of little movement, the national average for a gallon of gas increased by about 4 cents since last week to $3.12. This is -4 cents lower than a month ago and about -40 cents lower than a year ago.

• Even though the price of crude oil remains below $70 a barrel, prices at the pump are going up as more refineries make the seasonal switch to summer-blend gasoline. Summer-blend gas is less likely to evaporate in warmer temperatures and is more expensive to produce.