Dealerships will be subpoenaed in Grand Jury probe of Fiat-Chrysler

DETROIT – Fiat Chrysler's existing streak of 75 straight months of sales gains should have ended in 2013, according to revised sales figures released Tuesday by the automaker.

The revision comes as two federal agencies investigate whether the company inflated sales by pressing dealers to buy more vehicles.

The company is changing the way it records monthly sales. Applying the new method retroactively to the start of 2011 shows the company overstated sales for 30 months, including three in which it would have reported a sales decline. The company also understated sales for 36 months.

That means a much-touted string of monthly year-over-year increases actually ended in September of 2013 at 40 months.

A lawsuit by an Illinois dealership group alleges that competing dealers got incentives to report false sales.