Ford posts a 15.2% year-over-year sales increase in September vs. year-ago, but officials remain wary of how the government shutdown might affect auto sales.

Jenny Lin, Ford’s senior economist, stops short of predicting the shutdown will have a negative impact, but warns the outcome remains unpredictable.

“Any type of disruption in government operations would adversely affect government spending, consumer confidence and financial markets,” she says. “So we urge leaders to work together and remain hopeful the shutdown won’t be very long.”

Lin says consumer confidence dipped during the hotly contested debt-ceiling debate in the summer of 2011, but the current scenario differs due to pent-up demand for new vehicles and an aging U.S. car park.

“Today we believe a lot of things are going on in terms of positive momentum in the economy, so hopefully there won’t be another temporary impact on industry sales,” she says. “At this point we don’t know, it’s too early to tell.”

Most Ford-branded vehicles saw increases for September, despite Labor Day weekend sales being counted in August numbers.

On a volume basis, the F-Series fullsize pickup led the way, posting a 20.6% increase vs. year-ago to 57,289 units.

Ken Czubay, vice president-U.S. marketing, sales and service, says strong F-Series demand partially was due to September being an aggressive truck-promotion period for Ford, but notes the pickup still commands the highest transaction prices in the segment.

A new F-Series is expected to debut late next year, but the pickup still is besting newer competing entries, such as the recently launched all-new Chevrolet Silverado and GMC Sierra, which posted September sales of 32,506 and 13,438, respectively. 

“We’re thrilled to have truck leadership, and it’s getting to be truck dominance,” Czubay says.

On a percentage basis, the Fusion midsize sedan was the frontrunner with a 76.5% year-over-year increase to 19,972 units.

The tally represents Fusion’s best-ever September, Czubay says, noting the majority of Fusion conquest sales came from Japanese competitors. Fusions are expected to begin shipping soon from Ford’s Flat Rock, MI, assembly plant, which he says should help drive sales in the fourth quarter. 

The Fiesta B-car also posted strong results, with a 39.7% increase compared with like-2012 to 5,043 units. Most of the demand for the Fiesta came from non-traditional Ford markets, with deliveries up 41% in Los Angeles, 58% in Phoenix and 45% in Texas.

Vehicles turning in poor performances in September included the Ford Focus C-car, down 7.8%, Edge cross/utility vehicle, off 13.7%, and the Lincoln MKT CUV, which saw deliveries fall 7.7% to just 414 units.

Ford ended September with 577,000 light vehicles in inventory, including 144,000 utility vehicles, 245,000 trucks and 188,000 cars, equating to 75 days’ supply overall.