The U.S. average retail price of diesel soared 9.4 cents to $3.081 a gallon, the Department of Energy reported Sept. 23, bolstered by a crisis in Saudi Arabia after a drone attack on a major oil plant Sept. 14.

Gasoline prices have been sliding steadily for several weeks, and they’re promising to get even cheaper as crude prices fall and the U.S. moves into the summer driving season.

The U.S. average retail price of diesel dropped 1.2 cents to $3.151 a gallon, the Department of Energy reported. Concerns over demand and supply pushed oil below $59 a barrel, a level not seen since mid-March.

The U.S. average retail price of diesel climbed 2.2 cents to $3.169 a gallon, as crude oil stabilized around $63 per barrel, the U.S. Department of Energy reported April 29.

The U.S. average retail price of diesel climbed 2.5 cents to $3.118 a gallon, as crude oil dropped below $64 a barrel, the Department of Energy reported April 15.

The U.S. average retail price of diesel climbed 1.5 cents to $3.093 a gallon, and crude oil prices pushed past $64 a barrel to post a five-month high, the Department of Energy reported April 8.

The U.S. retail diesel average price dipped 0.2 cent to $3.078 a gallon, the Department of Energy reported, as the price of crude oil surged past $61 a barrel amid tighter supplies.

The U.S. retail diesel average rose 1 cent to $3.08 a gallon, the Department of Energy reported, as the price of crude oil slipped just below $59 per barrel amid concern over a possible slowdown in the U.S. economy.

The U.S. average retail price of diesel dropped 0.9 cent to $3.070 a gallon, according to the Department of Energy, even as crude oil prices broached the $60 mark for the first time in four months.

The U.S. average retail price of diesel increased ever so slightly the week of Feb. 4, rising to $2.966 a gallon, one-tenth of a cent higher than last week.