Sales of vehicles to commercial fleets from nine vehicle manufacturers rose 15 percent to 50,552 units in August in part due to a surge in passenger-car purchases, according to Automotive Fleet data.

Commercial fleets added 9,215 passenger cars for a 65.4 percent increase and 41,337 trucks, vans, and SUVs for a 7.7 percent increase. Passenger cars made up about 55.17 percent of sales during the month.

Year to date, fleet sales have increased 3.9 percent to 420,725 units. Sales of trucks, vans, and SUVs have far outpaced sales of passenger cars for the first eight months of 2015. Truck sales have grown 1.4 percent to 348,777 vehicles, while car sales have increased 17.9 percent to 71,948 units.