Do Pickup Truck Sales Make Any Sense?

I have lived all my life in cosmopolitan cities, I was in my 30s before I got a driver's license, I know little about cars and less about trucks. So do please help me out on this one: I am very, very confused by the year-end statistics now being released on pickup truck sales.

In 2007, as in every year, sales of light trucks - pickup trucks - were, at 8.5 million, significantly greater than automobile sales, which were 7.6 million. If I had to point to one reason for the atrocious fuel economy in the US compared to the rest of the world, this would be it.

But weirdly the year-on-year fall in pickup truck sales (2.4%) was smaller than the year-on-year fall in car sales (2.6%). That doesn't make a huge amount of sense: after all, when monthly car sales briefly overtook truck sales in May, the reason given was high gas prices. And truck ownership is naturally very heavy in the construction industry, which was hurt very badly in 2007.

And according to Micheline Maynard in the NYT, sales of the Ford F-series, the best-selling vehicle in the country for the 31st straight year, plunged by 13.2% in 2007. On top of that, the F-series' biggest competitor, the Chevrolet Silverado, saw sales fall 2.8%. Given those two numbers, and the fact that all the other numbers in the article are negative as well (Dodge Ram down 2%, Honda Ridgeline down 15%, Nissan Titan down 9.2%), how can total pickup sales have fallen only by 2.5%? (The number in the NYT article is one tenth of one percentage point away from the Wards Auto number, which is no big deal.)

More generally, why are pickup trucks so insanely popular in the US? And are the reasons strong enough to withstand high gas prices? I ask because without pickup trucks, Detroit is dead. But so far the pickup seems to be extremely good at refusing to die.

Update: A reader in Detroit comes to the rescue.

The 8 million number you're looking at is all trucks -- not just pickups. The definition of a "truck" for auto sales counting includes SUVs, vans, minivans and even small vehicles with a hatch and folding seats (such as the Chevrolet HHR). Pickup sales are hurting, but small SUV sales are way up.