Diesel and gasoline prices continued to fall this week, with both fuels dropping about 30 cents since April, according to the Energy Information Administration's weekly fuel update. Oil prices, which have fallen sharply in the past few months, ended higher on Monday after the euro rose against the dollar.

Diesel fuel prices dropped this week by 5.1 cents to $3.846 a gallon. The price of diesel has decreased by more than 30 cents since early April, when prices averaged $4.148 a gallon. Diesel fuel prices are down by an average of 9.4 cents from a year ago.

The price of gasoline also fell this week by 5.7 cents to an average of $3.612 a gallon. Gasoline prices are down almost 17 cents from prices one year ago and have come down almost 33 cents since April, when prices reached a high of $3.941.

A strengthening euro helped oil prices to rise this week, along with increased hope that European leaders will work out a plan to bring the region out of its debt crisis.

U.S. July crude rose 75 cents to settle at $83.98, after falling early to $81.21, the lowest since prices were last under $80 a barrel on October 6, 2011.

Brent July crude rose 42 cents to settle at $98.85 a barrel, having recovered after dropping as low as $95.63, the lowest intraday price since January 26, 2011.