U.S. automakers are expected to report big declines in August domestic sales despite stepped-up incentives, the Wall Street Journal reported. The research firm estimates sales for August will come in at around 1.21 million vehicles, or 13.4 million vehicles on a seasonally adjusted annual rate. That is down from the year-ago seasonally adjusted rate of 16.2 million vehicles, but up 6.3 percent from July. All major manufacturers had year-to-year retail sales declines through the first 14 days of August.