Wheel spacers and lowering springs

[Keith66]

Hi all
Have just bought Z4 3.0 SE 2006 , it came with 225-45-17 wheels and tyres but have replaced them with my old 135i coupe wheels 255-35-18 rear and 225-40-18 front.
Any suggestions for best size wheel spacers front and rear and suggestions for what size lowering springs.
Many thanks
Keith.

 

[Panta Rhei]

E87 OE 18" wheels are:
7,5x18 ET 49
8,5x18 ET 52

E85 OE 18" wheels:
8x18 ET 47
8.5x18 ET 50

You are 8,3 mm inside on fronts and 2 mm on rears compared to OE.

Keeping in mind that without lowering you can go +10 to +12 mm front per side and even +25 mm rear per side on OE E85 wheels and on lowered (eibach -30 mm - compared to OE standard suspension) however 5 mm front is max because of front inner wheel arch and this arse side marker design.

Quick maffs...

Use 15 mm front and 25 mm rear per side :driving:
This will push wheels out 23 mm rear and 6,7 mm front compared to OE on 5 mm fronts and 25 mm rears - all safe and tested.
15 mm spacers require longer wheel bolts. 20+ have through opening and current bolts can stay.

 

[Keith66]

Really appreciate your response mate.
Thank you very much for your advice
Keith