NEW YORK -- Oil dropped below $90 a barrel for the first time this year Monday, and pump prices dropped 3 cents during the weekend as drivers catch a break after two months of steep increases.Benchmark oil for April delivery fell 56 cents to finish at $90.12 a barrel in trading on the New York Mercantile Exchange. Earlier, the price fell as low as $89.33 a barrel.The national average for a gallon of gas fell to $3.75 a gallon Monday from $3.78 Friday. At one point this winter the price rose for 36 straight days. The 49-cent increase for January and February set a record for that two-month period.The price of oil declined as markets continued to digest the introduction in the U.S. of automatic government spending cuts, which could hurt the world's leading economy.Spending cuts of roughly $85 billion automatically kicked in Friday after President Obama and Congress failed to meet a deadline for striking a deal to avert or soften the reductions. Negotiations Sunday ended in a bitter impasse, and what happens next is anyone's guess.The International Monetary Fund has predicted that the spending cuts could reduce U.S. growth by some 0.5 percentage point in 2013.Traders also said that a report showing weakness in China's service sector contributed to the drop in oil.While a month ago oil was close to exceeding $100 a barrel, analysts said prices could continue to slide.A report from JBC Energy in Vienna noted that refineries are undergoing a higher than normal rate of maintenance. That reduces demand for oil, hurting the price. And Jim Ritterbusch of Ritterbusch and Associates in Illinois said recent strength in the dollar is a major reason that oil is down 7 percent a little more than 2 weeks.The increase in the dollar makes crude more expensive and a less attractive investment for traders using other currencies. While the euro was worth more than $1.36 Feb. 4, on Monday it was trading just under $1.30.In the U.S., refinery maintenance contributed to the early-year spike in gasoline prices. Refineries are switching from winter blends of gasoline to summer varieties, which are formulated to reduce pollution. That switch requires some downtime for a refinery, cutting supplies and boosting the cost of gas. The transition is still going on, and could somewhat mitigate the impact of cheaper oil in gas station prices.Brent crude, used to price many kinds of oil imported by U.S. refineries, fell 31 cents to $110.09 a barrel on the ICE Futures exchange in London.In other energy futures trading on the Nymex:• Wholesale gasoline fell 3 cents to $3.10 a gallon.• Heating oil slipped 1 cent to $2.92 a gallon.• Natural gas gained 7 cents to $3.53 per 1,000 cubic feet.