US auto sales failed to rebound in August as confidence sank and prospects dimmed for faster econ-omic growth, prompting at least a dozen analysts to lower estimates for light-vehicle deliveries for this year and next. August vehicle sales, to be released today, may have run at a 12.1 million seasonally adjusted annual rate, the average estimate of 14 analysts surveyed by Bloomberg. The pace averaged 12.5 million in the first half before slowing to 12.2 million in July. The August 2010 sales rate was 11.5 million, according to Autodata. Tempered projections for output and job gains led analysts surveyed by Bloomberg to trim an average of 900,000 car and light truck sales from their estimates for this year and 2012. The US economy may grow by less than 3 per cent through 2013, helping keep the unemployment rate above 8 per cent during that span, according to the Congressional Budget Office. \"We\'re going to grow and things are going to continue to get better, but at even a much slower pace than before,\" said Jeff Schuster, executive director of global forecasting at J.D. Power & Associates, which lowered its US auto sales estimates by 300,000 cars and trucks for 2011 and by 600,000 next year. Toyota Motor, Asia\'s largest automaker, may report an 11 per cent decline in deliveries, the average estimate of four analysts surveyed by Bloomberg. That would be the fourth consecutive monthly decline of 10 per cent or more following March\'s tsunami and earthquake that disrupted production. Sales may decline 25 per cent at Tokyo-based Honda Motor, the average of four analysts\' estimates. Nissan Motor Co., whose better supply of parts has buoyed inventory levels above its Japan-based rivals, may say deliveries climbed 18 per cent, the average of four analysts\' estimates. General Motors and Ford Motor, the largest US automakers, may report increases of at least 15 per cent. Concerns about the economy and financial markets are further delaying purchases put off during the recession and early recovery, said Schuster, who is based in Troy, Michigan. He is among the 12 analysts surveyed by Bloomberg who have cut their full-year auto-sales estimates since the first quarter. Outlook Deliveries may rise to 12.7 million cars and light trucks this year, the average of 18 analysts\' estimates. The average estimate in April was for 2011 sales of 13 million light vehicles. Industry-wide deliveries may climb to 13.6 million in 2012, the average of 15 estimates in a Bloomberg survey. The US averaged annual sales of 16.8 million vehicles from 2000 to 2007, according to Autodata.