Christina Rogers & Neal Boudette:

The U.S. auto industry, in tatters just four years ago, is emerging as an export powerhouse, driven by favorable exchange rates and labor costs in a trend experts say could drive business for many years.

In a sign of the turnaround, Honda Motor Co ., once a big importer of Japanese-made cars, says it expects to export more vehicles from North America—with nearly all of them coming from its U.S. factories—than it brings in from Japan by the end of 2014.

Last year, more than one million cars and light trucks were exported from U.S. auto plants, the highest recorded and a more than threefold rise from 2003, according to the U.S. International Trade Administration.