Shopper looks at a Jeep Cherokee diesel at the Hollywood Chrysler Jeep dealership.

Automakers reported a 5.5 percent rise in U.S. sales in August from a year earlier. The seasonally adjusted annualized rate of sales rose to 17.53 million vehicles from 15.94 million a year earlier.

The annualized rate is followed by economists and is calculated using seasonal factors supplied by the U.S. Commerce Department that account for sales from vehicles produced in North America or overseas.