August is the kind of month automakers and auto dealers love.
Demand is growing and supply is relatively limited, so dealers have had pricing power, and last month there was one extra sales day compared with August 2012—meaning that this August had five weekends versus four last year.
That combination is why many expect the raw sales numbers reported by automakers to be exceptionally high compared with a year ago.
Don't be fooled. What really matters for the industry and for dealers is the SAAR, or monthly sales rate.
(Read more: Auto leasing surges to record high)