Diesel prices continue their headlong retreat, falling 20 cents last week to a national average of $3.088, according to weekly figures from the U.S. Energy Information Administration.

The national average is now actually 21.5 cents less than it was a year ago. The highest prices were found in the New England region, at $3.42, while the lowest average was in the Midwest, barely topping $3 a gallon at $3.018.

The average price of a gallon of diesel has now fallen $1.676, or 35 percent, since hitting a record high of $4.764 a gallon in mid-July.

The falling fuel prices are the result of lower prices for crude oil. Crude oil prices fell 32.6 percent last month, the largest percentage since Nymex trading began in 1983, according to the U.S. Energy Information Administration.

However, energy industry experts warn that the lower prices are temporary. Prices are falling because of reduced demand and reduced economic activity, not because we have increased supply or increased energy efficiency, said BP Chief Executive Tony Hayward during the Abu Dhabi International Petroleum Exhibition and Conference Monday, reports the Associated Press.