Three of the four Orange County-based automakers beat the national sales pace for new vehicles in August, according to New Jersey-based market researcher Autodata Corp.

U.S. auto sales remained about flat on a year-to-year basis, adding 1.57 million cars and light trucks, and are on track to reach 17.81 million for the year.

Hyundai Motor America in Fountain Valley, with 72,012 units sold, had its best August ever, up 3% from a year earlier. Hyundai’s sales so far this year are up 2.5% to 514,175 cars and light trucks.

“Strong sales continued for CUV/SUV models in the Hyundai lineup,” the automaker’s President and Chief Executive Dave Zuchowski said in a statement. “The Tucson, our compact CUV, saw sales gains of 25.5 percent and the Santa Fe and Santa Fe Sport experienced gains of 30 percent and 18 percent, respectively.”

Hyundai is a subsidiary of Hyundai Motor Co. in South Korea.

Kia Motors America Inc. in Irvine, also a part of Hyundai Motor Group, reported selling 58,897 cars and SUVs, up 7.7% from a year earlier. Its year-to-date sales total is 426,160, a 5.4% increase.

“August [was] our fourth consecutive monthly sales record despite significant turbulence in the stock market and not having the benefit of Labor Day weekend sales,” said Kia Chief Operating Officer Michael Sprague.

Mazda North American Operations in Irvine dipped 4.4% to 29,938 vehicles last month. Its year-to-date sales added up to 216,091, which is about the same as the first eight months of 2014.

Cypress-based Mitsubishi Motors North America Inc. sold 8,289 vehicles—a 22.1% increase. The automaker has sold 65,701 so far this year, a 24.4% uptick over the same period in 2014.

U.S. auto dealers have sold 11.6 million vehicles so far this year, a 3.8% increase compared with the same eight-month period last year.