New vehicle sales for September are expected to exceed 1.38 million units, an increase of 4.1 percent from the same period last year, according to an online automotive study. Estimages of Mid-size SUV sales are already up for the month.

"Generous incentives and the recent decline in gas prices have helped to improve consumer demand for some larger vehicles, Jesse Toprak, Executive Director, Industry Analysis for said in a statement. We estimate that this month's mid-size SUV sales are up 15 percent over last year and that large truck sales are up six percent.'

The combined monthly U.S. market share for Chrysler, Ford and General Motors domestic nameplates will be 54.5 percent in September, down from 56.1 percent compared to a year ago. However, sales are expected to be up from 53.5 percent last month.