BMW recommends 225x40x18x8 FRONT and 255x35x18x8.5 REAR......I have 18x8.5 Breyton Inspirations (ET 44) on my 323i Sport with 225x40 tires all around... They fit fine but the 225's are too small for 8.5" wheels... The wheel sticks out past the tire a little.... A 235x40x18x8.5 is the best bet for the front and the 255x35x18x8.5 for the rear .... It seems that Breyton does not make 8" wheels and so you will have to put the 225's on the 8.5 inchers...