Diesel fuel prices national average rose for a second week, up 4.8 cents to $3.868 a gallon, while gas prices gained 4.7 cents to $3.674, the Department of Energy said Tuesday.

Diesel fuel prices national average pump rose for the first time in five weeks, edging up 1 cent to $3.820 a gallon, while gas prices increased 4.6 cents to $3.627, making fleet fueling more expensive for all fleet managers.

Diesel fuel prices on a national average pump declined for a fourth consecutive week, dipping 2.5 cents to $3.810 a gallon, while gas prices decreased 2.3 cents to $3.581, the Department of Energy said.

Diesel fuel prices, national average pump price fell for a third straight week, declining 6.2 cents to $3.835 a gallon, while gasoline dropped 7 cents to $3.604, the Department of Energy said Monday.

Diesel fuel prices declined for a second straight week, dropping 4 cents to $3.897 a gallon, the Department of Energy said Monday.

Oil finished the trading day Thursday at its lowest level since February, diving below $90 a barrel as equities markets plunged, Bloomberg reported. That is very good news for fleet manager trying to improve diesel fuel prices. It has been difficult lately for most companies to control their fuel management.

Diesel fuel prices will average $3.86 per gallon this year and $3.95 in 2012, the Department of Energy said, in line with its most recent forecast. This year’s projected cost is a penny lower than last month’s forecast, while the 2012 price matches last month’s estimate.

Diesel fuel prices fell for the eighth week in the past ten, declining 6.2 cents to $3.888 a gallon, the Department of Energy said Monday.