2011 X5d in the rain MPG drop?

[mthaynes]

In our new-to-us 2011 X5d with 50k miles: While on a road trip driving on the interstate I noticed as I drove thru some good rain that the MPG dropped from near 30 to about 20. It stayed there until a few miles after the storm. Several miles later on the same trip we entered into another rain storm and the same thing happened. Additionally, now back at home, driving in the rain, the wife commented that the idle seemed noisier. Are we ingesting water? Ideas?

[serge1]

I live in Seattle and drive in rain 7 months a year. No significant MPG drops.. maybe .02 MPG drop is there due to natural resistance of water on freeway.

How are you tracking MPG? If you are using the needle below tachometer - that's not overly reliable..