Lotus99

hi, from what I've read, most here when putting on spacers go either 10mm F & 15mm R, or 12mm F & 15mm R.

I have measured on my car how much is the gap from the tire to the outer edge of the fender to see how wide I could go with my 18" summers, and it's been 12 mm in the front and 30 mm in the rear.

I didn't realize the rear wheels were tucked in that much more than the fronts!

I was thinking of getting the 10's in the front, so that the fronts still tuck in a bit more than the rears, and would end up with 2 mm tuck in the front, and 15 mm in the rear.

But then I came across this on Turner Motorsports' site:

A note about 10mm spacers: Any 10mm spacer is considered a custom fitment. The stock hubcentric lip on BMWs can stick out by as much as 11mm. A 10mm spacer will bottom-out and leave a gap between the spacer and the hub which seriously compromises safety. The best way around this is using a larger spacer (12mm and larger do not have this issue) or check that the lip sticks out less than 10mm. In some cases you can modify the hub lip to get the 10mm spacer to fully seat on the hub.
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EDIT - I took off the front and rear wheels to actually measure the hub lips, and the front is 11 mm and the rear is 12 mm, conservatively, so I will definitely be getting 12's up front.

But now I'm thinking maybe I should get 20's in the rear. The rear wheels would still tuck in like 10 mm's even with 20's. Or is that going too big and there might even be some downsides? The car won't see any real hard cornering, unlike my 335 that goes to the track sometimes, so it won't have really strong sideways forces on it.

RIHI

I went with 12mm for the front and 20mm for the rear. I did not have rubbing issues until I lowered the rear of the car. Now it's lowered, but after setting the stiffness & compression of the dampers (mine are adjustable both for stiffness and compression) it no longer rubs.

I also have 18" BBS wheels and xDrive, however I forget the offset.

Hope this helps.

Lotus99

Thanks, good to hear. There's gotta be a few fingers tire gap on my wagon's rear tires, so vertical clearance shouldn't be an issue. I think I'll go with the 20 in the rear then.

2008Msport

burger motorsport for spacers! you can order them from n54 tuning.

I went 18mm in the rear with no issues, and I am planning for 12mm front.

Lotus99

Does anyone know why BMW has their rear wheels tucked in MORE from the fender in the rear vs. the front? Even on staggered setups? I always thought rears would tuck in less...

And is there any problem with upsetting that? That seems to be the case with most of their cars.

This car's got 30mm in the rear and 12mm in the front, and my 335 has about 19mm in the rear and 7mm in the front. I've put 12mm spacers on the rear of that car, so it's now even spacing on all 4 corners (7mm from the fender).

If I put 20mm spacers on the rear and 12mm in the front on the wagon, I'd end up with 10mm tuck in the rear and flush with the fender in the front.

Or should I keep the tuck in the front at 12mm and put no spacers on it, so it would be close to the 10mm tuck in the rear I'd end up with 20mm spacers on?

Lotus99

So I finally got around to installing my spacers. In the end I decided just to get 20mm spacers for the rear, because I figured I'd end up with an equal amount of tuck in from the fender for all 4 wheels of around 10mm.

Here's a before picture, and two after pics:
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Lotus99

By the way, in case this info comes in handy for anyone, I measured the fender height and wheel gap on the driver's side afterwards. I've got stock 18" wheels with stock tire sizes, and no suspension mods, other than front and rear RD Sport Sway Bars.

Front 69 cm ground to fender | Wheel gap 5.5 cm
Rear 68 cm ground to fender | Wheel gap 4 cm (with spacers)