McLEAN, Va. -

With also gauging how much Hurricane Irene effected the numbers, the chief economist of the National Automobile Dealers Association attributed August’s new-vehicle sales performance to one factor — inventory levels.

Paul Taylor believes the amount of vehicles on franchised lots not only swayed last month’s sales, but also likely will be the dominating factor as the second half of 2011 continues.

“The strong August sales results for the Detroit Three brands and Nissan underscore the importance of having an adequate inventory of new cars and light trucks for shoppers to view at dealerships,” Taylor emphasized.

“The Detroit Three sales in August were also helped by low interest rates and declining gasoline prices,” he continued. "In August, auto dealers needed to have in stock exactly what car shoppers were looking for in order to get them off the fence to buy a new car or truck."

Continuing on, Taylor turned his attention back to the manufacturing side of the inventory equation, returning to the events in Japan earlier this year.

“Detroit automakers built more cars to meet the demands of the marketplace while there was a shortage of cars coming from Japan caused by the March earthquake and tsunami,” the NADA economist pointed out.

“Nissan, one of the larger manufacturers in Japan, has been successful in keeping an adequate selection of new vehicles in front of customers,” Taylor pointed out.

To reinforce his point, Taylor cited inventory data from Ward’s Auto that indicated Nissan dealers had a 54-days’ supply of new vehicles at the end of July and the Detroit Three dealers averaged a 63-days’ supply of new models.

“Under these conditions of tight inventory followed by Hurricane Irene, the increase in new-vehicle sales of more than 8 percent in August was an accomplishment,” Taylor declared.

Taylor wrapped up his latest commentary by delving deeper into what Irene’s effects were.

“NADA estimates that about 3 percent of possible sales in August were pushed to future months by the disruption and flooding caused by Hurricane Irene,” he projected.

“New-vehicle sales in the 10 states affected by Hurricane Irene — which account for nearly 30 percent of U.S. car sales — were 10 percent lower in August as a result of the storm,” Taylor concluded.