Crude futures held above US$51 Friday as traders moved cautiously ahead of the U.S. Memorial Day holiday weekend, the start of the American summer driving season. After Wednesday's spike in crude prices fueled by an unexpected drop in U.S. crude stocks, trading was light Friday as the market seemed to refrain from any major moves, The Associated Press reported. Light, sweet crude for July was up 9 cents to US$51.10 a barrel in electronic trading on the New York Mercantile Exchange. Heating oil prices fell more than half a cent to US$1.4422 a gallon (3.8 liters), while unleaded gas was down to US$1.4455 a gallon. In London, Brent crude futures for July delivery gained 11 cents to trade at US$50.27 a barrel. The American Automobile Association predicted last week a record 36.9 million Americans will travel 80 kilometers (50 miles) or more this Memorial Day weekend, with nearly 85 percent leaving home by motor vehicle. The U.S. Energy Information Administration's latest petroleum data showed U.S. gasoline inventories rose 600,000 barrels to 215.4 million barrels, up from 203.6 million a year ago. However, crude oil inventories fell 1.6 million barrels to 332.4 million barrels in the week ending May 20 from the previous week. Crude prices are about US$7 lower than their all-time high of US$58.28 set April 4.