The national average price of diesel fell 3.2 cents this week in the fuel's second straight decline

, according to weekly figures released by the Department of Energy.

Two weeks ago, diesel was up 3.3 cents after dropping 19.9 cents over five straight weeks. This week, diesel took a slight tumble to land at a national average of $2.924 a gallon. This week's price is 33 cents higher than the same week last year.

Diesel prices were highest on the West Coast and in the Central Atlantic region, where it averaged $3.077 and $3.055 a gallon, respectively. The Gulf Coast and Lower Atlantic had the lowest averages this week, at $2.866 and $2.889 a gallon, respectively.

Crude oil prices fell along with diesel as investors grew concerned about the slowing economic growth, according to reports by Dow Jones. Crude was down 16 cents Tuesday to settle at $71.98 a barrel on the New York Mercantile Exchange. This has been the longest period of declines since mid-May, Dow Jones reported.