Diesel fell 3.6 cents to $3.991 a gallon, while gasoline continued to drop, the Department of Energy said Monday.
Gasoline fell 4.5 cents to $3.349 a gallon — its 10th decline in the past 12 weeks, DOE figures showed. Since mid-September, the motor fuel has plunged 52.9 cents.
The diesel decline leaves it under $4 for just the third time in the past 17 weeks, even though it has dropped in seven of the past eight weeks.
Diesel dipped 0.7 cent last week but jumped 5.8 cents two weeks ago, the biggest increase in three months. Its $4.15 price in mid-October was the highest in more than four years.
Oil, meanwhile, fell for a fifth day, with crude futures falling 37 cents to finish the trading day Monday at $85.56 a barrel on the New York Mercantile Exchange, Bloomberg reported.
Each week, DOE surveys about 350 diesel filling stations to compile a national snapshot average price.