I've had 2 BMWs with the 3.0 engine and have never had a problem with either. I purchased an '07 X5 4.4 after driving the 3.0 and finding it underpowered. Given that the ride and power of the V8 is so much greater than the 3.0 six and given that the difference in fuel economy is essentially 1 mpg (which you will lose if you drive it aggressively), I can't see why you would consider the 3.0 anyway. But, the X5 sure does suck up the gas which is now over $4.15 per gallon for premium in California. Sure you don't want a hybrid? :-)
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