U.S. new car and truck demand rose 3.8 percent last month, a promising sign for automakers counting on a strong spring selling season, The Detroit News Reports. General Motors Corp. sales rose 6.3 percent on strong demand for midsize cars and Cadillac products. At Ford Motor Co., brisk sales of the F-150 pickup fueled a 2.2 percent gain. Hurt by weak car sales and slumping minivan demand, sales at DaimlerChrysler AG’s Chrysler Group fell 2 percent, the paper reports. Despite growing vehicle inventories, GM and Ford will maintain current production plans. A year ago, auto sales were hurt by the U.S. invasion of Iraq. Generous discounts, tax refunds and mortgage refinancing are helping to keep auto sales elevated, analysts say. Asian automakers posted mixed results. Toyota Motor Co.p. sales rose 5.5 percent and demand grew 30 percent at Nissan Motor Co. Honda Motor Co. sales dipped 5 percent.