The average price of U.S. retail diesel fuel climbed another 5 cents last week to $2.84 a gallon, reaching a seven-month high, and the Department of Energy warned that prices are unlikely to fall anytime soon.

The average retail price of diesel fuel jumped 11.4 cents to $2.79 a gallon, the largest one-week jump in 18 months, the Energy Department reported.

The U.S. average retail price of diesel fuel dipped by 0.5 cent to $2.676 a gallon last week, its second straight tiny decline, the Department of Energy said.

The average national price of retail diesel fuel fell for a second straight week, dipping 0.5 cent to $2.676 a gallon, the Department of Energy reported Monday.

Following six straight weekly increases, the average national price of retail diesel fuel dipped 0.4 cent to $2.681 a gallon, the Department of Energy reported Monday.

For decades, diesel engines — prized for their durability and pulling power — have dominated broad segments of the heavy truck and equipment markets. As gasoline prices rose in the 1970s, diesels made quick inroads in light-duty markets as well.

The average national price of diesel fuel gained another 5.9 cents from last week in rising to $2.685 a gallon, a sixth straight increase, the Department of Energy said Monday.