Despite strong sales of pickup trucks throughout much of 2012, research firms J.D. Power and Associates and LMC Automotive expects that pattern to shift this month, with sales of midsize sport utility vehicle (SUVs) and large pickups expected to be the only segments of the light vehicle market not to show year-over-year retail sales gains in September.

"We expect retail sales to level off through the rest of the month, but still maintain a strong share of total sales," said John Humphrey, J.D. power’s senior VP- global automotive operations.

However, he stressed that overall retail sales of light vehicles in early September were 15% higher than they were a year ago at the same time, which is reflective of a healthy market.

J.D. Power and LMC predict that total light-vehicle sales in September are expected to increase 11% from September 2011, with volume at 1.15 million units. With vehicle inventory levels in check, fleet sales in September are projected to reach 200,400 units – only a slight increase from September 2011 –representing 17% of total light-vehicle sales.

The firms added that September new-vehicle retail sales are projected to come in at 952,200 units, representing a seasonally adjusted annualized rate (SAAR) of 11.8 million units – pointing out that new-vehicle retail sales date in September is consistent with an expected 12% annual increase in retail sales vehicle for 2012 versus 2011.

By segment, according to J.D. Power’s and LMC’s data, sub-compact conventional, compact conventional and midsize conventional models each are expected to show retail sales growth of at least 25% this month compared with September 2011 – reflecting a marked change from the sales pattern that’s been in place for much of the year to date.

For example, Ford Motor Co. noted that sales of its F-Series sales grew a total of 19% this past August to 58,201 vehicles, reflecting 13 straight months of monthly sales gains and its best sales month in 2010 for the F-Series.

Yet Ken Czubay, Ford’s VP for U.S. marketing, sales and service, added that the automaker began witnessing a transition to more fuel efficient vehicles in August as well – possibly heralding the shift in light vehicle demand J.D. Power and LMC are now chronicling.

"As fuel prices rose again during August, we saw growing numbers of people gravitate toward our fuel-efficient vehicles,” he said. “Customers increasingly value savings at the pump.”

That’s one reason why Czubay said Ford’s Escape compact utility sales reached 28,188 units in August – a 37% increase versus the same month in 2011 – and why Ford added a third crew to its Louisville Assembly Plant in Kentucky to support that increase in demand.

Overall, throughout the first eight months of 2012, North American light-vehicle production volume posted consistently strong performance, said LMC: up 22% from the same period in 2011. Nearly 1.9 million additional vehicles have been manufactured in 2012, which shows the remarkable recovery from the challenged production environment in 2011, the firm said.

That being said, though, while LMC continues to forecast a strong year for total light vehicle sales in the U.S. at 14.3 million units, looking ahead to 2013 brings a higher level of uncertainty that may impact overall volume growth.

"During the next few months, car buyers will be processing further economic news, additional details on the European crisis, as well as the forthcoming presidential election, likely creating an environment with higher volatility,” noted Jeff Schuster, the firm’s senior VP of forecasting.

“Right now, consumer willingness or need to overlook the economic uncertainty is the driving force behind the recent strength in light-vehicle sales,” he explained.