EPA estimates come from.... the EPA. They are often behind in their certifications, hence likely the delay in posting the rating on the web. However cars can't be sold without out the rating on the sticker. My guess it the EPA estimated the rating and then had to correct it down after further testing.

Omy my 50i, I have gotten close to 20 on pure highway trips, equal or better to the EPA 19 MPG estimate. But even the shortest city drives or any "fun" I have drops it fast.

__________________
Richard
Sir Snaps-a-lot, 9 Time Dragon Slayer (54 runs!)
2011 X5 50i Alpine White, Biege Nappa /Lt Poplar M Sport
2009 Z4 35i, Black Sapphire/Ivory-Black/Anthracite

Gone but not forgotten: '08 550i, '06 X3, '06 650i, '02 M5, '99 540i