They are 16" and came as the standard wheels for most of the 2010 model year. Early production models got 17" wheels, but BMW had supply issues and dropped them from the Value package for the rest of the model year.
Present - '06 E90 330i sport; Past - '04 E46 ZHP, '00 E46 328i
www.bmwcca.org member #388003 - Use me as a referral & you could win a one day ///M Driving School!!