Sonic Automotive’s scaled-back, standalone EchoPark used-vehicle operation is narrowing its losses and gaining positive momentum, said its executives during the dealership group’s most recent quarterly earnings call.

EchoPark’s income loss of $16.9 million in its third quarter that ended Sept. 30 represents a 46% improvement over the year-ago quarter loss of $31.1 million according to Sonic’s financial results.

In the third quarter, EchoPark grew its ...