Chrysler Group LLC, a subsidiary of Italian company Fiat SpA (BIT:F), said Tuesday it sold 143,017 vehicles in the U.S. in September, a 1 percent year-over-year increase from September 2012 but a 13.6 percent drop from August, helped by continued strong demand for the Jeep Grand Cherokee and the Ram pickup truck and despite a double-digit drop in Fiat sales.

"The company's Ram pickup trucks continue to grow despite the launch of new-generation pickups from General Motors and ongoing pressure in the segment from Ford and Toyota," said Bill Visnic, senior analyst for the automotive information provider "And although sales for Jeep were down in September and are off slightly for the year, the Grand Cherokee continued its great run in 2013."

Jeep sales were down 5 percent despite robust sales of the Grand Cherokee, which saw 14,906 units roll off dealer lots last month for a 19 percent year-over-year gain for the Jeep brand leader. Dodge sales grew 3 percent with the Durango SUV up 66 percent to 4,964, the Dart compact up 51 percent to 7,922, and the Charger two-door growing 49 percent to 8,713. Despite this robust sales activity, the Caravan minivan (down 19 percent to 10,946) and Avenger sedan (down 41 percent to 5,099) provided growth headwinds for the Dodge brand.

The Ram pickup, Chrysler's No. 1 seller, jumped 8 percent to 28,145 units. Meanwhile, Fiat fell 24 percent with the 500 city car plunging 49 percent to 2,126 units. The new 500L five-door mini, which went on sale late last year, sold 1,031 units.