U.S. retail gasoline prices declined for a second week in a row while diesel fuel costs increased slightly, the Energy Department (search) said Monday.

The national pump price for regular unleaded gasoline fell 1.1 cents over the last week to $1.898 a gallon, up 25 cents from a year ago, according to a survey of service stations by the Energy Information Administration (search).

The EIA, the Energy Department's (search) analytical arm, also said truckers paid a slight 0.3 cent more for diesel fuel this week, with the average price at $1.986 a gallon, up 40 cents from a year ago.

The drop in gasoline prices may be shortlived. The EIA said it expects motor fuel costs to rise heading into the busy spring driving season.

Even though gasoline inventories are in the upper portion of the average range for this time of year, gasoline demand is very strong, the agency said.

The EIA's weekly survey showed the retail price for cleaner-burning reformulated gasoline, sold in polluted metropolitan areas, was unchanged at $1.949 a gallon.

The West Coast had the most expensive regular unleaded gasoline, with the price up 3.5 cents to $2.04 a gallon. Los Angeles topped the agency's survey of cities, with the price of gasoline also up 3.5 cents to $2.138 a gallon.

The Gulf Coast states had the cheapest fuel, with the price down 2 cents to $1.813 per gallon. Among major U.S. cities, Houston had the lowest pump price, with fuel down 2.2 cents to $1.769 a gallon.

The weekly report also showed gasoline prices were down 0.7 cent to $1.981 in Miami, down 1.9 cents to $1.923 in Cleveland, down 3.6 cents to $1.90 in Chicago, down 2.2 cents to $1.897 in New York City and up 2.2 cents to $1.879 in Seattle.

Truckers in the New England states paid the most for diesel fuel at $2.197 a gallon, down 2.5 cents from the prior week. The Gulf Coast states had the cheapest diesel at $1.915 a gallon, down 2.3 cents.