The American auto industry yesterday reported its best October sales in a decade, led by double-digit growth at all three Detroit carmakers, the New York Times reported yesterday. Industry analysts projected that the seasonally adjusted annual sales rate would exceed 18 million vehicles for the second consecutive month as consumers continued to splurge on new pickup trucks and sport utility vehicles. Overall, automakers said that they sold 1.46 million vehicles during the month, which was a 13.6 percent increase over the 1.28 million sold in the same period a year ago, according to the market research firm Autodata Corporation.