Diesel dipped 1.7 cents to $3.894 a gallon, the seventh straight decline, the Department of Energy said in its weekly survey.
Despite the dip, trucking’s main fuel is 4 cents higher than the same week last year, DOE said late Monday.
Gasoline, meanwhile, edged up 0.4 cent to $3.303 a gallon, its second straight weekly increase of less than a penny.
Gas has gained almost a nickel in four straight gains, and its price this week is 8.8 cents below a year ago, DOE said.
Diesel has dropped 14 cents in seven drops since the last week of November, when it rose 5.8 cents. That was preceded by five declines totaling 17.4 cents, according to DOE records.
Diesel took its biggest drop in the Midwest region, where it fell 3.6 cents to $3.834 a gallon.