Why the Clunker Numbers Baffled People

GM logo, General Motors logo
GM logo, General Motors logo

I thought the final numbers on the Cash for Clunkers program were fairly straight forward. The Department of Transportation released the top 10 selling models and what percentage of vehicles were sold by each auto maker. But those numbers don't make sense to many of you.

Bill e-mailed, "It seems strange that GM can come in 2nd in total sales without a car in the top 10 individual sales. Please expand how GM accomplished this."

Given the fact General Motors has a far larger line-up of cars and trucks than some of its competitors (Honda for example), the collective sales of all those GM models can easily add up to 17.6% even if GM did not have a top ten selling model. Remember, the clunkers program only required people trading in gas guzzlers to get a model that averages 4 MPG more than the old model. As a result, there were trucks bought through the program. Not a ton of them, but certainly a sizable number. Given GM's dominance in the truck/SUV market means the company did sell trucks to some of the people trading in clunkers. Add those sales to the GM car sales, and you can see why GM outsold Honda, even though the Japanese auto maker had three top ten sellers, while GM had none.

I explained this to Tom after he wrote, " I surely hope CNBC is not in the propaganda business for GM. This is a clear case where statistics can be deceiving." There's no propaganda going on, just a reporting of the stats handed out by the Department of Transportation.

Wait, could it be the DOT is giving out misleading information? Doug thinks so. He wrote, "The methodology for calculating the top 10 list may be flawed as the DOT over-segments products." He does bring up a good point. If you over classify vehicles, based on specifications, broad vehicle lines (like the f-series pick-up) would be broken into smaller segments.

Hopefully, we will eventually get a detailed report from Washington about which models sold.

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