Fuel prices continue a big decline with diesel posting its biggest weekly drop in recent memory, according to U.S. Energy Department figures.

The national average cost of on-highway diesel fell 12 cents this week from last week to $2.933 per gallon, its lowest price since September 2010. Compared to the same time a year ago the national average cost of diesel is 94 cents less.

Prices declined by double digits over the past week all in the many different sections of the country, ranging from 10.8 cents in the Central Atlantic states for an average of $3.131, also the highest priced part in the U.S., to as much as 14.3 cents in the Rocky Mountain region for an average of $2.884 per gallon.

The least expensive region is the Gulf Coast, down 12.1 cents, for an average of $2.843.

Compared to this same time last year all sections of the country report their average diesel cost is down at from at least 91.1 cents in the Lower Atlantic states to as much as $1.046 in New England.

Gasoline also declined over the past week, but not as much as diesel, with regular grade shedding 7.3 cents for an average of $2.066 per gallon. Compared to the same time a year ago the price is $1.23 less.

It currently ranges from a low of $1.844 in the Gulf Coast region to a high of $2.382 in the West Coast region.

Not surprisingly, the price of crude oil tumbled Tuesday in New York trading, falling $2.30 for the day and settling at $46.39 per barrel amid concerns of weaker worldwide economic growth.

The International Monetary Fund cut its global economic growth forecast for 2015 by 0.3% of a percentage point to 3.5%, following news that China’s economy, the second largest in the world, grew 7.4% last year, reportedly its weakest performance in decades. Also, Iran, a key producer of oil, hinted oil prices could go as low as $25 per barrel unless OPEC does something to curb oversupply in the worldwide marketplace.

Compared to last Tuesday’s opening price the cost of oil is up by 70 cents and it posted its first week-to-week gain last week in two months.