DETROIT -- The Jeep Grand Cherokee will have a shortened 2013 model year so that in January Chrysler Group can introduce a diesel engine and eight-speed automatic transmission for the 2014 model, internal Chrysler sources say.
Dealer orders for 2013 Grand Cherokees began this month. The 2013 model, which will begin production in August, will continue with the five-speed automatic that the Grand Cherokee has had since mid-2010.
In January, the Grand Cherokee will pick up an eight-speed transmission licensed from ZF Friedrichshafen AG and built at Chrysler's transmission plant in Kokomo, Ind.
At about the same time, the Grand Cherokee will offer an optional 3.0-liter diesel engine from Fiat-owned VM Motori S.p.A. in the United States, a Chrysler source said.
The 3.0-liter diesel is available already on the Grand Cherokees sold overseas and is rated at 241 hp and 406 pounds-feet of torque.
Mated with a five-speed transmission, the diesel delivers 23 mpg city and 33 mpg highway.
Chrysler-Fiat CEO Sergio Marchionne said in January that the automaker would introduce a diesel for the Grand Cherokee in 2013.
A Jeep spokesman declined to comment on the powertrain plan.
Chrysler previously announced that the Jefferson North Assembly plant in Detroit where the Grand Cherokee is built will forgo the usual summer shutdown to keep up with demand for the hot-selling SUV. The factory also assembles the Dodge Durango.
Chrysler said it will add a third crew of 1,100 workers to Jefferson North to boost production this November rather than after the first of the year, as had been announced earlier.
Sales of the Grand Cherokee have been brisk since it was re-engineered in the summer of 2010. Through May, Grand Cherokee sales are up 38 percent to 62,611 units.
Introduction of the eight-speed transmission should greatly improve the Grand Cherokee's current fuel economy of 17 mpg city/23 mpg highway.
When Chrysler replaced the five-speed automatic in its flagship sedan, the Chrysler 300, for the 2012 model year, its mileage rating improved from 18 mpg to 19 mpg city, and from 27 mpg to 31 mpg highway.