Hi , not very technical and getting a bit confused, so any help/advice would be appreciated.
Bought my 2006 2.5i z4 about 18 months ago, previous owner seems to have put M sport (style 400) alloys on it with 225/45/18 tyres on the front and 255/40/18 tyres on the back.
I'm about to change the tyres later this year and want to go back to the original sizes of 225/40/18 front and 255/35/18 back, also going from run flats to non run flats.
Not knowing much about this, does this seem OK or can anyone see any problems.
Thanks.

Bought my 2006 2.5i z4 about 18 months ago, previous owner seems to have put M sport (style 400) alloys on it with 225/45/18 tyres on the front and 255/40/18 tyres on the back.
I'm about to change the tyres later this year and want to go back to the original sizes of 225/40/18 front and 255/35/18 back, also going from run flats to non run flats.
Not knowing much about this, does this seem OK or can anyone see any problems.
Thanks.
