The national average retail price of diesel fuel increased by 2.6 cents, pushing the weekly average to $3.252 a gallon, according to the U.S. Energy Department’s weekly report released Sept. 4. Trucking’s main fuel now costs 49.4 cents a gallon more than it did a year ago, when it was $2.758 a gallon.

The U.S. average retail price of diesel inched down 0.3 cent to $3.223 a gallon, while crude oil prices were lower despite ongoing tensions over trade and the Middle East.

The U.S. average retail price of diesel rose 2 cents to $3.236 a gallon, while the price of a barrel of oil climbed amid a tightening of inventory.

The U.S. average retail price of diesel jumped 6.1 cents — the largest single increase of the year — to $3.104 a gallon as oil climbed past $68 a barrel amid signs the supply glut is fading.