According to reports, auto sales were steeply up for the month of November, with experts holding to an increase in the seasonally adjusted annual rate (SAAR) of between 15.0-15.4% – a four-year high. Some have been quick to suggest superstorm Sandy as a key cause, creating a spike in trade as people were forced to replace storm-damaged vehicles.

Not so fast. Here are five reasons why the November boost may not be as large as we’re told – and why Sandy may not be “to blame”.

1. Much of the overall boost comes from other factors

Sales for the whole year were already at a four-year high. Back at the beginning of October, auto

sales experts said that this “robust pace was fed by consumers replacing older vehicles, the wide variety of new fuel-efficient models on the market and the greater availability of credit at low interest rates.”

September’s car sales helped push the SAAR to its highest in four years, at 14.9%. October and November continued this torrent of sales. Both months, like each one over the last year, featured gains in car sales year on year. Sandy may have helped make November’s SAAR higher than September’s, but the difference is about half a million cars or fewer – and that’s not enough to account for why November 2012 was so much better than 2011.

2. The jump in car sales from October to November is less than the number of cars damaged by Sandy

We can’t quite know yet how many people will eventually buy new cars because their autos, more than 230,000 overall, were lost in the storm. In addition, about 30,000 sales were lost in October. Put together, we might assume that there were 260,000 fewer cars on the road after Sandy.

November’s sales, however, only rose by about 20,000 units over October’s. We can’t say whether or not car sales would actually have fallen in November in a universe without Sandy. Sales did fall this time last year, by 2.52%; instead, in 2012, November’s sales improved on October’s, but only by 1.11%. That hardly adds up to a Sandy bonanza.