Chevrolet, Ram pickups zoom in Ford F-150 lull

Both Chrysler and General Motors took advantage of Ford's transition to a new aluminum F-150, but boosting sales of Ram and Silverado pickups in September.

Sales of the F-Series — the most popular car or truck in America — fell 1% in September to a still-robust 59,863.

But Chevrolet Silverado sales jumped 54% in for the month to 50,176 and sales of the GMC Sierra rose 25% to 16,763.

Pickup trucks continue to be the most popular and profitable vehicles of the Detroit Three. Even if Ford's slip is a temporary blip, it was still noticed across the industry.

"GM's truck month could not have been more perfectly timed," Jessica Caldwell, senior analyst at Edmunds.com said in an email. "With Ford F-150 production on the shelf, GM had an easier path to showcase Silverado to truck shoppers."

Meanwhile, sales of the Ram pickup rose 35% to 38,498.

Ram has been gaining market share in the light-duty pickup segment for several years. Earlier this week Ram said it would boost production of diesel engines for the Ram 1500. In September, Chrysler said it increased the annual production capacity at its Warren Truck plant by 28,500.

Still, the F-Series remains the king of the pickup segment and Ford is betting big that customers will embrace the F-150's aluminum body that will go on sale soon.

Until then, John Felice, Ford's vice president of U.S. marketing and sales, said the Dearborn automaker is trying to hold the line on incentives for the 2014 model as competitors get more aggressive.

Ford increased its incentives for the F-Series by about $280 in September from August, but Felice said that was $160 lower a year earlier.

For the first eight months of the year the F-Series outsold Silverado by 165,000.

"We have maintained our leadership by a wide margin this year," Felice said. "We have the strongest pickup truck in the marketplace and our customers have been very very loyal."