The average price of on-highway diesel continued falling into final week of 2014, down significantly from its high for year and hitting its lowest price since December 2010, according to the U.S. Energy Department.

It fell 6.8 cents over the past week, registering $3.213 per gallon. This compares to a high for 2014 of $4.021 recorded in March and is 69 cents less than the same time a year ago.

Regionally, diesel prices declined in all part of the country over the past week, ranging from 4.2 cents in the Central Atlantic states for an average of $3.35, to as much as 9.9 cents in the Rocky Mountain region for a $3.239 average.

Compared to a year ago prices are down between 65 cents in the Rocky Mountain region to as much as 75.6 cents in the West Coast region.

Trucking's main fuel currently ranges from a low of $3.121 in the Gulf Coast states, down 5.4 cents in the past week, to a high of $3.365 in New England, 6 cents less than a week ago.

Gasoline also continued a similar decline, with regular grade falling 10.4 cents over the past week to $2.299 per gallon. Compared to the same time a week ago the price is $1.032 lower and it's currently at its lowest price since May 2009.

Gasoline prices currently range from a low of $2.073 in the Gulf Coast region to a high of $2.617 in the West Coast region. Regionally, prices are down at least 8.2 cents over the past week and are at least 87.2 cents less than the same time last year.

The spread of diesel fuel prices over gasoline has grown to nearly 80 cents per gallon, the widest spread since 2008, according to the U.S. Energy Information Administration. A year ago, the spread was just over 50 cents.

This happened as oil closed on Monday at its lowest level in six years in New York trading, down 50% from its 2014 high hit on June 20, closing at $53.61 per barrel, and falling $1.12 for the day. The decline follows a 4.2% drop in oil prices last week which marked the fifth straight weekly decline.

The drop is also the fastest in eight years, with the faster drops only happening in 1985 to 1986 and 1990 to 1991, according to Marketwatch.com

The drop in crude prices is due to increasing U.S. oil production along with high production by OPEC member nation’s while worldwide crude demand has slowed. Analysts opinions vary widely on when oil will move back up, from just a handful saying the days of high prices due to the OPEC oil cartel are over to those on the other side saying they will move up soon, though hardly anyone is soon expecting a sudden return to prices over $100.