Rough idle/start in cold weather?

[sidmiller]

I have a 2005 X5 4.4 (Sport, Cold Weather Pkg., etc.) that I purchased about 6 months ago. Now that the cold weather is setting in a bit, I am noticing a very rough start and rough idle when first starting the engine each day. Before the cold weather, I noticed that sometimes the car seemed to hesitate or act like it was misfiring when the engine was cold, but now it seems much worse. Dealership says, "BMW's run rich when they are cold and everyone complains about it." This just doesn't seem right to me. As an example, when the engine is cold, I can keep in the car in Park, gently press the gas pedal to increase the RPM's very slightly, and the car will shake and chug like it wants to stall. But if I continue to press the gas pedal further , it seems okay. EVERY time I take it to the dealership, I cannot replicate the problem, so there is no help there.

Also, gas mileage is much lower than expected in this car. 13-14 mpg in town and barely 18 highway. I have a rack on top for the bikes, so a slight drop in mileage is to be expected, but this much?

Thoughts, ideas? Is this a typical BMW trait when they are cold?

Thanks, friends! It's makin' me crazy!

SM