EPA MPG ratings for the 2015 X4 are up on fueleconomy.gov:
2015 X4:
www.fueleconomy.gov/feg/bymodel/2015_BMW_X4.shtml
2015 X3:
www.fueleconomy.gov/feg/bymodel/2015_BMW_X3.shtml
Page must have only gone up today because even Google has yet to crawl the page.
Dangit, should've gone with the 35i. Only one mile difference between the two.