Fleet automotive sales, which have buoyed new-vehicle deliveries all year, continued their rise in September.

Sales into large commercial, government and rental fleets, not including dealer and manufacturer supply, jumped 26% year-over-year, Cox Automotive said, with those into rental fleets alone surging 53%.

Cox credited fleet sales with the year’s new-vehicle deliveries health.

“The success of the new-vehicle market this year and the increase in our full-year forecast is mainly due to the return of fleet sales,” said Cox Senior Economist Charlie Chesbrough.

Pent-up rental and commercial fleet demand is behind the increases, Chesbrough said, as soon after the pandemic descended on the industry, carmakers prioritized supplying dealerships with vehicles instead of fleets. Since vehicle production started its recovery, fleet sales have been catching up.

Year-to-date fleet sales are up 39%, Cox said, rental fleet sales alone up 72% and government fleet sales up about 44%.

General Motors’ fleet sales grew the most of any large manufacturer for the second month in a row, Cox said.

Retail sales, meanwhile, including estimated fleet sales to dealer and manufacturer supplies, are up about 18%, for a seasonally adjusted annual rate, or SAAR, of 12.9 million, up 1.1 million year-over-year, Cox said.

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