That's why I didn't install my wheels without putting on the lowering springs

 

No XI, 525i, 2007.... So spacers only for rear?, I'm kind of lost when talking about spacers for wheels...

Thanks for all your Help

 

the gap above the tire will still be there even with spacers. you need to lower it with springs or coil overs

 

Absolutely true! Considering these http://www.modbargains.com/H-R-Sport...-Series-M5.htm

What would spacers exactly do? How are these installed? Would spacers compromise stability?

 

Why were those tyres chosen when the OEM size is 245/40R18?

 

Wheels have wrong offsets. As far as I remember you can fit 245 tire on 8" wide rim. You will need spacers. 15mm on front and 20mm in the rear should work. The gap looks so bad because you have non sport model. Sport suspension sits lower, so coil overs or lowering springs will be needed. GL!

 

You bought rims that have an offset of 34mm when it needed to be 20mm So what happens is the rims mounts closer to the strut or might even touch the strut housing. Thats why your shop said you wont have room. Adding a 15mm thick spacer in the front will move your rim towards the fender side giving you the clearance from the strut housing and giving you the ability to run a wider tire.


If the 18x8 wheels you bought were offset 20mm to begin with then you could as an option run spacers for the flush look or for a wide track feel for handling etc...All non XI cars are usually et20 in the front and ET33 in the back. M cars are more aggressive and run ET12 and ET 28.


Your rims are probably from either XI or 3 series type rims they look close to a m3 wheel. All those cars run 34 front 37 rear.

For reference the offset is stamped on the back of the wheel ETXX along with size of the rim

 

+1

 

if I where you I would put them on craigslist and get ones that were less complicated

 

Unless I am mistaken, the sidewall height of a 225/45-18 and a 245/40-18 is virtually identical (within 3mm) so the choice between these two tires will not change the gap size at all. Correcting the offsets with spacers should make it look like a somewhat smaller gap, because the tire will be closer to the fender lip. The gap with the new wheels is actually the same as it was with his stock wheels, but as usual, a bigger wheel with a narrower tire (giving same overall height) always accentuates the look of the gap. Bottom line is that these wheels with spacers will look identical to the correct offset wheels, and tire choices won't change the gap (unless you puton oversize tires), only the width of tread, so final remedy is lowering.