In its defense, just think what BMW is up against. Every day that it is awake, it has to figure out a new way to grow. With its product line already stuffed with every imaginable variety of engines and body styles, it has to look for ideas outside the automotive mainstream that are still consistent with its self-image. Since minivans and pickup trucks are out of the picture, it has to search far and wide to come up with marketable concepts.

So somebody got the idea of putting a sportier coupe-type body on the existing undercarriage of the X5 sport utility vehicle. The X5 was already pretty sporty as sport-utilities go, so the product planners really had to reach to to come up with their new concept.

The evidence suggests they stretched too far and didn’t exercise enough discipline along the way. The X6 seats four in considerable comfort, and the first-rate controls and running gear will be familiar to BMW lovers everywhere.

But the sloping roof imposed by the new style — an unusual feature for a BMW – has severely compromised the rearward vision. And the massive body resting on the X5’s all-wheel drive undercarriage jacks up the weight of the X6 to just a few ounces shy of 5,000 pounds. That puts it in the same category as the porcine Porsche Cayenne and makes it 700 pounds heavier than a Cadillac SRX. Trust me, the X6 is much bigger than it looks in pictures. All that excess avoirdupois leads to a mediocre fuel-economy rating of 15 mpg city/20 mpg highway.

BMW’s bean-counters have also been asleep at the switch. Since it is made in BMW’s South Carolina plant instead of the home base of Germany, the X6 escapes a direct hit from the strong euro, though it still clocks in with a healthy $52,500 base price for the V-6 model. Add some high-priced accessories, though, and the sticker price races up to the one on my test vehicle of $72,500. The additional 20 grand covers the Cold Weather, Premium, Premium Sound, Rear Climate, Sport and Technology packages. Delete the running boards, heated rear seats and HD radio, and you save $1,000.

On the road, the X6 felt big and heavy, though never cumbersome. And climbing a ledge-studded mountain road in northwestern Connecticut, it never lost its composure. Still, my weekend with the the vehicle left me wondering: Suppose BMW had been only half as ambitious and produced a variant of the smaller X3 instead? I imagine everyone would be better off.

Pummeled by the weak dollar and high cost of commodities, BMW is in a financial slump at the moment and has set some aggressive financial targets to reach by 2012. My guess is the X6 won’t help very much.