Diesel and gasoline prices dropped for the fifth straight week, but oil prices continue to fall due to concerns over Europe, particularly Greece's economy.

Diesel fuel prices dropped by by an average of 5.3 cents to $4.004 a gallon, according the the Energy Information Administration's weekly fuel upsate. This is the lowest the average price of diesel has been since late February.

Prices are down by an average of 5.7 cents from a year ago.

Gasoline prices dropped by 3.6 cents this week to $3.754 a gallon. That's more than 20 cents lower than gasoline prices a year ago. Prices in the West Coast, the only region to see an increase, went up 12 cents.

Light, sweet crude oil for June delivery on the New York Mercantile Exchange settled $1.35 lower, at $94.78 a barrel, a new low for 2012. The decrease is due to mounting concerns about Greece's economy and rising global oil supplies.

Traders said oil prices are heading for a critical juncture around $92.50 a barrel. This could clear the way for prices as low as $85 a barrel, a level not touched since last October.

To see the EIA's complete weekly fuel update, click here.