Rising car and truck sales have prompted Ford Motor Co. to add a week of production at 13 North American factories, including Essex Engine in Windsor, Ont.   

The move, which will see the Windsor plant close for only one week during the summer shutdown period, will allow Ford to produce an additional 40,000 vehicles in North America this year.   

Ford said Tuesday that it would cut in half the normal two-week summer shutdown at six assembly plants and seven engine and parts plants.   

Normally auto plants close for two weeks in early July as they switch over to make vehicles for the next model year.   

Through April, U.S. auto sales have been running at an annual rate over 14 million, up substantially from last year's 12.8 million. Ford sales through the first four months are up five per cent compared with a year ago.   

Many analysts are forecasting sales of around 15 million in 2013.

Factories run at capacity   

At Ford, most factories have been running at capacity, and the company is adding third shifts at three plants just this month to meet higher demand, said Jim Tetreault, vice-president of North American Manufacturing.   

"Requiring more capacity from our plants is a good problem to have and having the flexibility to add a week of production in our plants goes a long way toward solving it."   

In addition to the Windsor plant, factories that will work the extra week include Chicago Assembly, which makes the Ford Explorer SUV and Ford Taurus and Lincoln MKS large cars; Dearborn Truck, in Dearborn, Mich., which makes F-Series trucks; Louisville Assembly in Louisville, Ky., which will make the new Ford Escape small SUV; Kentucky Truck in Louisville, which makes heavy-duty pickups and the Lincoln Navigator and Ford Expedition big SUVs; Michigan Assembly in Wayne, Mich., which makes the Ford Focus compact, and Kansas City Assembly in Claycomo, Mo., which makes F-150 pickups.    Other factories with the added week include Dearborn Engine, Chicago Stamping, Cleveland Engine No. 1, Lima Engine in Lima, Ohio; Sterling Axle in Sterling Heights, Mich., which makes transmission and engine parts; and the Rawsonville parts plant in Ypsilanti Township, Mich.   

Ford now has enough plant capacity to make 2.6 million vehicles in North America, but the company plans to push that up to three million this year with added shifts and other changes, spokeswoman Marcey Evans said. The 40,000 is part of the planned increase, she said.   

Ford shares were down 14 cents, or 1.4 per cent, at US$10.52 in afternoon trading Tuesday in New York. The stock is up from a 52-week low of $9.05 in early October, but  down 31 per cent from a high of $15.35 almost a year ago.