The supply of unsold vehicles started to swell at U.S. Volkswagen dealerships after the mid-September stop-sale order on diesel cars.
The automaker had disclosed to U.S. regulators that software on 2009-15 diesel cars was designed to run cleanly only when the engine detected it was undergoing emissions testing.
Despite finishing September in disgrace and unable to sell some popular diesel models, the VW brand eked out a 0.6 percent unit sales increase for the month. But that gain rode on a one-time calendar quirk, and VW trailed the market's overall 16 percent growth.
The Volkswagen brand started October with a 114-day supply of stock, up from 95 days Sept. 1 and well above the industry average.
Audi also stopped selling some diesel vehicles, but its stock barely budged, declining one day to a 57-day supply.
VW Group's woes barely made a ripple in the calm seas of the overall market. U.S. automakers and dealers started October with a 60-day supply, exactly the average for Oct. 1 over the previous 10 years.
That's an increase from 55 days on Sept. 1, a normal seasonal rise as automakers' factory output of the latest model year gets up to speed after midsummer changeovers.
All of the seven best-selling automakers boosted Oct. 1 stocks modestly from a month earlier.
Fiat Chrysler had the smallest increase of the bunch, up two days to 76. American Honda posted the greatest stock increase, up eight to a 55-day supply.