Last week's average price of diesel slid 5.6 cents to $2.13 per gallon, the lowest it has been since May of 2005.
The diesel price is following a downward trend that has been apparent since last summer. The most recent price is $1.42 per gallon lower than for the same time last year, according to Department of Energy data.
Ultra low sulfur diesel followed a similar trend last week, falling 5.9 cents to $2.138 per gallon.