General Motors Co.  (GM)  said sales in August increased 7.5%, blowing away analysts' expectations of a 1.9% increase for the month. 

GM snagged a 0.5 point uptick in retail market share for the auto industry with a push for crossovers and SUVs that began last month. The company also improved inventory figures, ending August with an 88-day supply, down from a 104-day supply in July. 

Sales at Ford Motor Co. (F)  in August dropped 2.1%, a narrower-than-expected decline compared to analysts' expectations of a 2.4% sales decrease.

Ford ended August with slightly higher inventory than last month, managing an 81-day supply vs. a 77-day supply in July. Truck sales were up 9.3%, but SUV sales decreased 11.3% due to fleet sales timing, Ford said.

On a conference call with analysts Friday morning, Ford said it expected Hurricane Harvey damaged 'several thousand' of its vehicles in the Houston area, but estimated no more than 10,000 cars in inventory would be affected. Ford said it has a 33% larger market share in Houston than it does nationally, primarily because of a "rich mix" of trucks in the area. 

Overall auto industry sales are expected to decline 2% to 3% from August of 2016, Ford said, which is an improvement over last month. In July, sales declined 7% from the same period last year.

Ford traded up 2.6% at midday on Friday while GM gained 2.7%.

Updated from 9:40 a.m. ET.

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