Diesel prices continue to drop closer to the $4-a-gallon mark, with the national average at $4.059 according to weekly retail figures released by the U.S. Energy Information Administration.

That's 6.2 cents per gallon less than last week and the eighth week in a row the average price has fallen since hitting a record high of $4.764 in mid-July.

The highest average retail prices were seen in the New England region, at $4.312, and the lowest in the Midwest and Gulf Coast regions, were retail diesel prices were $4.015.

Meanwhile, crude oil prices edged up Monday because of concerns of Hurricane Ike disrupting oil production in the Gulf of Mexico. In addition, OPEC is meeting Tuesday and there is wide speculation they will trim production to keep oil prices from falling below the $100-a-barrel mark.

The 13-nation group could agree to trim output informally before waiting until later to officially cut production. This would be done by members cutting their excess production above their OPEC quota, which would remove oil from the market but not amount to a formal change in policy, explains a story from the AFP news agency.