The average price of a gallon of diesel fell about a penny over the past week, with Monday's numbers from the Department of Energy showing a national average of $2.79, down from last week's $2.801.

The average is only about 2 cents less than it was a year ago.

The Central Atlantic region reported the highest average, at $2.912, while the Gulf Coast has the lowest, at $2.733.

Crude oil prices climbed Monday, thanks to a weak dollar and the expectation that recovering economies around the world, including Japan, will mean more demand. The price of a barrel of oil rose $2.5 to close at $78.90 a barrel. The OPEC oil cartel also signaled that it feels $75 to $80 a barrel for crude, according to published reports.

In the November edition of its monthly Short-Term Energy Outlook released last week, the DOE's Energy Information Administration boosted its energy price forecasts for the remainder of this year and 2010. The EIA now believes that diesel prices will average $2.79 per gallon (19 cents higher than October's projection) in the current quarter and then rise to an average of $2.84 per gallon (revised up from $2.66) in the first quarter of 2010.

Crude oil prices, which account for more than 60 percent of the cost of diesel, are also expected to rise through the forecast period.