Another offset question...

[Duke.higham]

Hi all,

I’m planning to run a set of aftermarket wheels on my 30 mm lowered Z4 E85 and wanted to check fitment experience before I commit. The wheels I’m looking at are:

• 18×8 J ET30 with 225/40R18 up front
• 18×9 J ET30 with 235/40R18 on the rear

Stock offsets are ET47 front and ET50 rear, so these will sit noticeably wider, and I’m wondering if anyone has experience with similar specs on a lowered E85.

• Do these fit without rubbing on the front or rear?
• Did you need to roll/shave the arches, or add camber to avoid rub?

Appreciate any feedback!

 

[Zedebee]

It depends on how lowered your car is. You would be unlikely to have trouble with either of those at a standard Sport ride height. If you had, say, a 2” drop you may get some rubbing on the inside of the arch liner, but not the arch itself. Not sure about the rear though, as your wheel size and tyre profile are both a size bigger than they ought to be. Standard is 8.5J 255/35R18. 235 seems pretty stretched for a 9” wheel too, but maybe that’s the look you are going for?

 

[Duke.higham]

It depends on how lowered your car is. You would be unlikely to have trouble with either of those at a standard Sport ride height. If you had, say, a 2” drop you may get some rubbing on the inside of the arch liner, but not the arch itself. Not sure about the rear though, as your wheel size and tyre profile are both a size bigger than they ought to be. Standard is 8.5J 255/35R18. 235 seems pretty stretched for a 9” wheel too, but maybe that’s the look you are going for?

It's dropped 30mm. Good point about the tyres, they do seem very stretched for a 9" wheel. Not quite what I was going for tbh but struggling to find any other reasonably priced wheels about haha

 

[Mr Tidy]

I ran my 2nd Coupe on a set of E89 wheels so the fronts were 8J ET29 with 225/40 x 18 tyres and had no rubbing, but it was on standard M-Sport suspension. Although that is 15mm lower than an SE IIRC so if your car had SE suspension yours is only another 15mm lower.

But my rears were 8.5J ET40 with 255/35 x 18 tyres. As Zedebee said I'd want more tyre on a 9J rim. There is plenty of room in the arch to run a bigger tyre - I've got OE 9J rims on my MC with 265/40 tyres, but with an ET30 offset you might have a problem.

224 wheels on the M are 9J ET30 on the rear, so could you organise a test fit of one of those? Or fit a 20mm spacer and see if a standard 18" staggered rear wheel would fit, it's only half an inch difference on the rim and it's the tyre that may rub.

Alternatively do those wheels have an 8.5J option? If not I'd be tempted to go for an 8J square set-up.

 

[Rsipad]

Wheel fitment should be fine. I was running 17x9 et30 square with moderate lowering and no scrubbing except for hard compressions on backroads. Camber gain from a slightly more aggressive alignment would help, but it all depends how much you drop the car.

Agree with Mr Tidy and Zedebee; tire size is off. 245 is the perfect tire width for a 9" wheel to minimize flex without stretch. You can go wider to 255, but you'll have more sidewall, even with the same section %, so a higher chance of rubbing. Anything less than 245 on a 9" and you have less tire to protect from curb rashing the lip of the wheel.