On a volume estimate of 1.18 million units, S&P Global Mobility expects U.S. light-vehicle sales in September to realize a calendar-induced decline of approximately 12% year-over-year. On the bright side, this would translate to a seasonally adjusted rate (SAAR) of 16.0 million units, a notable bump from the 15.2 million unit reading in August and sustaining a volatile pattern for this monthly metric since May. The month-to-month volatility in the SAAR reading reflects the current state of auto demand.

“New vehicle sales remain stuck in neutral,” said Chris Hopson, principal analyst at S&P Global Mobility. “The overall tenor of the auto demand environment remains one of consistent, but unmotivated volume levels as consumers in the market continue to be pressured by high interest rates and slow-to-recede vehicle prices, which are translating to high monthly payments.”

Despite increasing to 2.88 million units at the end of August, dealer advertised inventory in the U.S. has also largely leveled out since the spring.

 “With 2025 model year vehicles now becoming available at an increased rate (up 65% vs. July), pressure to sell down remaining stock of 2024 model year vehicles will begin to mount,” stated Matt Trommer, associate director of product at S&P Global Mobility.

Continued advances in inventories and incentives are expected but given reports of some automakers culling output expectations for the remainder of the year, affordability issues are expected to remain stubbornly sticky even as the first interest rate cut was made. In its September 2024 forecast update, S&P Global Mobility has lowered its calendar year 2024 U.S. sales outlook to 15.9 million units, down from a previous projection of 16.0 million units.