Penske's net income rose to $57.7 million in the quarter as revenue climbed to $3.4 million, the company said in a statement.
Income from continuing operations rose 14 percent to a record $56.9 million.
In the first quarter, new-vehicle sales increased 10 percent to 45,745 units and used-vehicle sales also rose 10 percent, to 40,076. Regionally, total new and used retail sales rose 13 percent in the United States and 5 percent in international markets.
Penske ranks No. 2 on the Automotive News list of top 125 dealership groups in the United States with retail sales of 180,764 new vehicles in 2012.
In the first quarter, the average transaction price rose 3 percent for new vehicles to $38,099, while falling 3 percent for used vehicles to $25,076.
CEO Roger Penske said in a statement: "Penske Automotive Group delivered strong operating results and record profitability in the first quarter, including double-digit growth in operating income, income from continuing operations and earnings per share."