Ally Financial had the highest auto loan market share in the second quarter, according to Experian, driven primarily by increases in the company's used-vehicle loan portfolio.
Capital One Auto Finance and Toyota Financial Services rounded out the top three.
Ally captured 5.31 percent market share for total auto loans, up 61 basis points year over year, and made up 5.67 percent of the used auto loan market in the second quarter.
Ally has made a strategic effort to increase the company's used-loan portfolio in recent quarters, which is up 95 basis points from the second quarter of 2017.
Ally Financial CEO Jeffrey Brown said during the company's second-quarter earnings call that used originations generally are booked at higher yields and have more predictable loss performance behaviors than new-vehicle loans.
In the second quarter, 51 percent of Ally's originations were used auto loans, up from 47 percent a year ago.
Capital One Auto Finance fell 28 basis points behind Ally, with 5.42 percent in used loan market share. Wells Fargo Dealer Services was third in used loan market share, with 2.76 percent.
Toyota Financial Services led new-vehicle loan market share, with 8 percent of total originations in the second quarter, up from 6.9 percent a year earlier. Ford Motor Credit was No. 2 in new-loan origination share, with 6.42 percent, followed by Chase Auto Finance, with 6.27 percent of the market.
Ally came in second place for total auto loan market share in the second quarter of 2017, according to Experian, originating 4.7 percent of total auto loans. Capital One Auto Finance held the largest auto loan market share a year ago, with 5.74 percent. Chase Auto Finance came in third, with 3.62 percent.