The industry's 55-day supply of unsold light vehicles at the end of 2010 was virtually flat from the 53-day supply at the close of 2009.
But 2010 and 2009 could not have been more different in terms of inventory. The volatility of 2009 disappeared, replaced by rigid automaker control and discipline.
After plummeting in late 2008, U.S. auto sales hit rock bottom in early 2009.
Supplies were feast or famine in 2009. They set a record high of 118 days on Feb. 1 and a record low of just 30 days seven months later, after cash for clunkers cleaned out dealer lots. Measured by units, industry inventories swung from 3.0 million in February to 1.4 million in September.
But last year automakers adjusted, closely aligning production and sales. Many adopted better controls. For example, instead of monthly, Ford Motor Co. now tracks sales, production and inventory daily, with weekly senior-management reviews.
And in 2010 stock levels stayed close to the industry's traditional ideal of 60 days.
The 2010 fluctuation, from high to low, was the smallest in 19 years of records. It went from a high of 71 days on Feb. 1 to a low of 48 days during the usually lean summer.
Individual automakers were closely bunched last month, much as they were all year.
Among the six largest players, Chrysler Group had the biggest supply with 63 days, and American Honda Motor Co. the lowest at 48 days.