The average price at the pump for a gallon of diesel fuel dropped six cents this week, and has fallen 15 cents since the start of the war in Iraq, according to the U.S. Dept. of Energy. The department's Energy Information Administration said the average price recorded yesterday was $1.602. The Midwest ($1.526) and Gulf Coast ($1.529) regions both have average prices under $1.60, while buyers in New England are paying an average of $1.823. The price at the pump is falling because crude oil prices fell after the start of the war, and that lower price is being passed on to the consumer, analysts said. However, the instability in day-to-day market prices could cause future volatility.