Kia's Sportage, Sorento and Carnival SUVs / Courtesy of KiaKia Corp. posted record monthly sales in the United States in August, while Hyundai Motor Co. reported a decline in numbers, the Hyundai Motor Group affiliates said Wednesday.Kia America sold 83,793 vehicles last month, up 1 percent from a year earlier and marking its highest-ever monthly sales.Cumulative sales in the first eight months of the year rose 3 percent on-year to 590,377 units, also setting a record for the January-August period.The Sportage SUV was Kia's bestselling model, with 18,723 units sold.Hyundai Motor America, on the other hand, saw its U.S. sales decline 2 percent on-year to 86,977 units in August, despite continued strength in hybrid vehicles.Hyundai's hybrid sales jumped 33 percent from a year earlier, setting a record for the month of August.Among major models, sales of the Palisade SUV fell 18 percent on-year to 12,729 units, while the Ioniq electric vehicle lineup also posted weaker sales.In contrast, sales of the Tucson and Santa Fe SUVs increased 18 percent and 5 percent on-year over the period, respectively.Q.Q.Q.