Big 3 brands increased their certified pre-owned sales by nearly 20 percent in August and pushed their year-to-date sales above half-a-million units.

According to Autodata Corp., domestics sold 77,918 CPO units last month, which was up 19.8 percent year-over-year.

Through eight months this year, they’ve increased certified sales by 13.7 percent, moving 545,034 CPO cars.

Breaking those figures down, Ford’s brands sold 24,977 CPO vehicles in August (up 16.9 percent) and have moved 179,935 units so far this year (up 18.0 percent).

Chrysler Group reported 13,760 certified vehicles in August (including Fiat sales), which was its best month ever for CPO and a 20.8-percent increase.

Through August, its CPO sales (including Fiat) have reached 96,686 units, a 17.3-percent hike.

(Note: the aforementioned Big 3 totals do not include Fiat results)

Over at General Motors, certified sales for its Buick, Chevrolet, GMC, Pontiac and Saturn brands reached 37,426 units in August, up 21.9 percent year-over-year, Autodata indicated.

Yearly sales through eight months are up almost 10 percent at 255,077 units.

Elsewhere at GM, Cadillac had 1,848 certified sales in August (up 16.2 percent) and year-to-date CPO sales are at 13,720 (up 10.0 percent).