Z4 M Definitive Wheel Spec Thread

[HBC]

Stock 06 M

Will the following rims/tires fit on my Z4M?

19x8.5 ET33 front 255/35/19
19x9.5 ET35 rear 275/35/19

[Shigg614]

Originally Posted by XMetal

It all comes down to tire selection. I'm telling you from my experience and what I've read through this entire thread. I run Conti Extreme DW 275/30R19 and with the 25 offset gets me about 15mm clearance from the inner fender liner and 10mm clearance from the outer fender were it meets the rear bumper. Some have reported rubbing the outer fender with a 22 offset...so your mileage may varies. I always go on the high side in offset because it is easier to correct if you rub on the inner fender - just add spacers to correct. If you go on the low side, it's difficult to correct if it rubs the outer fender - only options are running narrower stretched tires or add more negative camber, which can only do so much.

I have 35 offset for the front and run 245/35R19 - same Conti Extreme DW and that slightly rubs the outer fender liner (where the bumper and fender meets) on full compression. I know someone who also have a 35 offset that runs the same size tire (245/35R19), but with Michelin PSS and he has a slight rub on the inner rear fender liner on full lock. But most don't have issue with a 35 offset with 245/35R19 tires. A 30 offset will push it out another 5 mm, so it will clear the inner fender strut and liner for sure, but you may risk rubbing on the outer fender, which may be corrected (to a degree) if need by adding more camber and or running a narrower tire. Again, your mileage may varies depending on tire selection.

That clears things up thank you.

Take away points are
- Take tires into consideration
- Higher offset = safer (in general)
- Rubbing on outer fender? Adding camber or choose a narrower tire

[pyshin]

Found this recommendation from Apex (Apex E85/E86 Z4M Fitment Guide)

Front: 18x9" ET30 or ET31 with 255/35-18 tires
Rear: 18x10" ET25 with 275/35-18 tires

Unfortunately they did not have any pictures of this exact setup, I searched through all of the pages with no luck.

Is anyone running this setup? If so would you post photos showing fitment and share alignment settings? Thanks in advance

[S54MC]

I'm looking to purchase some Volks Te37sl 18x9.5 +22 rear and maybe 18x8.5 +35 this should fit with no issues, correct? Thank you in advamce

[Mos6689]

Ok read through all 26 pages of this thread now & it’s a great help. I’m getting new wheels in the post tomorrow & they’re:

19x8.5 et 35
19x10 et 22

To be put on a Z4MC. I can see on here some have run very similar setups, so I know they’ll work but I’m now looking at tyres and not quite sure what to go for? I plan to lower the car 10mm rear & 20mm front but don’t want to be messing about with rolling the fenders to avoid rubbing. Any experts about to help?

I’m thinking at the moment to run 235/35 on the fronts, as this increases ride height 5mm so allows me to lower the 20mm. Hoping this won’t look stretched? 245/35 seems to be the general consensus but worried the extra diameter will mean rubbing?

On the rears I’m stuck between going 265/35 or 275/30? Leaning towards the 265/35, because I’m thinking the extra 5 between the 30 & 35 will be the difference between being crashy and bone shattering to moderately comfortable. Am I right in thinking this? Use the car as a daily so don’t want to ruin my experience in it.

Thanks in advance for any help/insight anyone’s able to give.

[XMetal]

Originally Posted by Mos6689

Ok read through all 26 pages of this thread now & it’s a great help. I’m getting new wheels in the post tomorrow & they’re:

19x8.5 et 35
19x10 et 22

To be put on a Z4MC. I can see on here some have run very similar setups, so I know they’ll work but I’m now looking at tyres and not quite sure what to go for? I plan to lower the car 10mm rear & 20mm front but don’t want to be messing about with rolling the fenders to avoid rubbing. Any experts about to help?

I’m thinking at the moment to run 235/35 on the fronts, as this increases ride height 5mm so allows me to lower the 20mm. Hoping this won’t look stretched? 245/35 seems to be the general consensus but worried the extra diameter will mean rubbing?

On the rears I’m stuck between going 265/35 or 275/30? Leaning towards the 265/35, because I’m thinking the extra 5 between the 30 & 35 will be the difference between being crashy and bone shattering to moderately comfortable. Am I right in thinking this? Use the car as a daily so don’t want to ruin my experience in it.

Thanks in advance for any help/insight anyone’s able to give.

If you do 235/35 or 245/35 on the front, you should go with 265/30 or 275/30, respectively for the rear to make all of your rolling diameters to be almost the same. Having /35 on front and rear, but with the rear being wider means that the rear will have a larger overall rolling diameter than the front. Having too great of a difference between front and rear rolling diameters may put your traction/stability control in a frenzy

[Mos6689]

Thanks for your advice Xmetal. This throws my understanding off a bit now. Bare with me here.

I may well be wrong but this is how I was calculating it:

So OEM setup is:

18x8 225/40 RD (rolling dia) 637.2mm fronts
18x9 255/40 RD 661.2mm rears

OEM difference fronts to rears + 24mm

Stock they’re both running 40 and the rears are wider. So there’s a difference front to rear in the rolling diameters from stock. So I was looking to get as close to the difference between the rolling diameters from stock as possible.

Back to my initial thoughts on sizes, I did take RD into consideration and here’s stats on them:

19x8.5 235/35 RD 647.1mm fronts
19x10 265/35 RD 668.1mm rears

Difference fronts to rears +21mm

What you’re suggesting:

19x8.5 235/35 RD 647.1mm fronts
19x10 265/30 RD 641.6mm rears

Difference fronts to rears - 5.5mm

OR

19x8.5 245/35 RD 654.1mm fronts
19x10 275/30 RD 647.6mm rears

Difference front to rears -6.5mm

Are you saying it’s better to have the RD front and rear as close to eachother as possible? If so, what benefit does this offer from OEM setup?

I understood changing the difference in RD from front to rear is what would throw up problems like speedo error at +\- 2.5% & possibly the ABS/traction faultering.

Be interested to hear what you and others think of this with the numbers. In parts of Europe (Germany for example) it’s illegal to have a speedo difference of +\- 2% when changing wheels. Also RD must be within a certain tolerance of OEM which only allows you a specific set of tyre sizes to choose from. Thought it was good practice to follow this but I’ve only recently got my head around all of this wheel jargon. Always just bought a set of rims and chucked them on without a second thought. Only matching PCD & nothing else. So I may well be wrong in my thought process.

[Mos6689]

Just been pointed out to me that fronts aren’t 225/40/18 OEM. They’re 225/45/18. Assumed because my car is low mileage and on 224’s it was all stock. FML back to the maths board!

FWIW in light of the OEM size being wrong, I can understand your suggestions now even before going to the drawing board!

[Mos6689]

Just worked it out again based on the ACTUAL front OEM tyres. Basically only have 2 choices really:

Stock is
225/45 fronts RD 659.7mm
255/40 rears RD 661.2mm
Difference of +1.5mm front to rear

CHOICE 1
235/40 fronts RD 670.6mm - Arch gap decrease by 11mm. Speedo -1.6%
265/35 rears RD 668.1mm - Arch gap decrease by 7mm. Speedo -1%
Difference of -2.5mm RD

CHOICE 2
245/35 fronts RD 654.1mm - Arch gap increase by 5.6mm. Speedo +0.9%
275/30 rears RD 647.6mm - Arch gap increase by 13.5mm. Speedo +2.1%
Difference of -6.5mm RD

My main reason for wanting to lower is purely to get rid of the crap rear springs the car comes with. No one does like for like replacements & the closest to stock is eibach -10mm rear & -20mm front.

Prefer the specs on choice 1. Closest to OEM spec but concerned the decrease in the arch gap, between tyre & fender, is going to be a problem when I lower it?

[bwright657]

Just reinforcing what Xmetal posted about going up in tire sizes. 235 fronts should have 265 rears. 245 fronts should have 275 rears.

Unfortunately for 19's on the rear there isn't a way to not mess with rolling diameter compared to stock. But keep in mind BMW also over-reports your speed from the factory. On stock wheels an indicated 80mph is actually 77. Almost all OEMs do this because the EU has legislation against under-reporting speed.

[ANILE8]

Originally Posted by XMetal

It all comes down to tire selection. I'm telling you from my experience and what I've read through this entire thread. I run Conti Extreme DW 275/30R19 and with the 25 offset gets me about 15mm clearance from the inner fender liner and 10mm clearance from the outer fender were it meets the rear bumper. Some have reported rubbing the outer fender with a 22 offset...so your mileage may varies. I always go on the high side in offset because it is easier to correct if you rub on the inner fender - just add spacers to correct. If you go on the low side, it's difficult to correct if it rubs the outer fender - only options are running narrower stretched tires or add more negative camber, which can only do so much.

I have 35 offset for the front and run 245/35R19 - same Conti Extreme DW and that slightly rubs the outer fender liner (where the bumper and fender meets) on full compression. I know someone who also have a 35 offset that runs the same size tire (245/35R19), but with Michelin PSS and he has a slight rub on the inner rear fender liner on full lock. But most don't have issue with a 35 offset with 245/35R19 tires. A 30 offset will push it out another 5 mm, so it will clear the inner fender strut and liner for sure, but you may risk rubbing on the outer fender, which may be corrected (to a degree) if need by adding more camber and or running a narrower tire. Again, your mileage may varies depending on tire selection.

I have had this combo before but let me tell you there is a problem and I see a LOT of guys on here do it too.

For a 19" wheel on our cars a 245/35/19 on the front is a big mistake if you are using 275/30/19 on the rear.

And as you know you cannot use a taller 35 profile tire in the rear to even it out because it will rub.

A front 245/35/19 will fit, but apart from just looking weird, the car won't ever sit right. Your front tires will be 6.5mm/0.26" higher than the rears.

A 235/35/19 for the fronts would have been a better match.

[lelandr]

Reading through this thread, it SEEMS like I will be ok, but didn't find anyone else running exactly what I have planned. There are 26 pages to this...whew.

1. Track car with occasional street driving.

I got what I thought was a good deal on 2 sets of used Apex ARC-8. The rears are going to rub (18x10 ET25 285/30). I'm also concerned about the front. The wheels I bought are 18x9" in the front with ET30. However, the ARC-8 wheels don't clear the stupid F&F Brembo brakes that came on the car. Using washers to test, I would need an 8mm spacer to get close to the 3mm of clearance all around that Brembo stipulates.

This would result in an 18x9" with effective ET22 using a 255/35. The car is lowered with -3.1 deg camber in the front. I suspect that this will result in some rubbing, but it seems that others may have run this low an offset with wider wheels without.

The car came with the beautiful 513M, 18x9, Et29 f and 18x10 ET40 (12mm spacer) and these fit very well with no issues other than a very slight rub under track use. Finding these reasonably priced ain't easy...

I'm starting to think that the best course of action is removing and selling the Brembos since they are such a PITA to deal with.

Thanks!

[Caosa]

Hey guys,
Have an opportunity to get a set of wheels and tyres for cheap -

F: 9.5x19 +19
R: 10.5x19 +30

Current tyres:
2x255/30/19
2x275/30/19

Its lowered on BR coils. Any issues with rubbing? Couldnt find similar set up in the spreadsheet?

[3002 tii]

Originally Posted by lelandr

Reading through this thread, it SEEMS like I will be ok, but didn't find anyone else running exactly what I have planned. There are 26 pages to this...whew.

1. Track car with occasional street driving.

I got what I thought was a good deal on 2 sets of used Apex ARC-8. The rears are going to rub (18x10 ET25 285/30). I'm also concerned about the front. The wheels I bought are 18x9" in the front with ET30. However, the ARC-8 wheels don't clear the stupid F&F Brembo brakes that came on the car. Using washers to test, I would need an 8mm spacer to get close to the 3mm of clearance all around that Brembo stipulates.

This would result in an 18x9" with effective ET22 using a 255/35. The car is lowered with -3.1 deg camber in the front. I suspect that this will result in some rubbing, but it seems that others may have run this low an offset with wider wheels without.

The car came with the beautiful 513M, 18x9, Et29 f and 18x10 ET40 (12mm spacer) and these fit very well with no issues other than a very slight rub under track use. Finding these reasonably priced ain't easy...

I'm starting to think that the best course of action is removing and selling the Brembos since they are such a PITA to deal with.

Thanks!

Those wheel specs are fine but the 285 tire is the issue, and frankly overkill. Stepping down to 275 or 265 would work.

Re spacer, is that based on a wheel template or have you actually tried mounting the wheel? The issue is the convex spokes so I can see how there might be a slight clearance over the calipers. But I’d just run a spacer and run a 245 tire.

[Kuky]

Hello, I need some help with the wheels.

I have a set of Dinan wheels from my E46M3. Here are the spec of the wheels F: 9.5X19 ET45 R: 10X19 ET35 I am thinking to use 3mm wheel spacers at the front and 5mm wheel spacers at the rear. Do you think these wheels would work for the Z4m? can the front accommodate 265/30/19 tires (or I should stick with the 245/35/19) and R with 275/30/19?

Thanks in advance!

[lelandr]

Originally Posted by 3002 tii

Those wheel specs are fine but the 285 tire is the issue, and frankly overkill. Stepping down to 275 or 265 would work.

Re spacer, is that based on a wheel template or have you actually tried mounting the wheel? The issue is the convex spokes so I can see how there might be a slight clearance over the calipers. But I’d just run a spacer and run a 245 tire.

Thanks for the post, sorry I missed this--like 2 months ago...

The reasoning for the 285 is that it is smaller in diameter than the available 275 tires.

The real answer is for me to quit being cheap and buy a proper set of squared up wheels all around.

[Caosa]

Hey guys,

Got a great chance to grab some Vorsteiner wheels. I just want to know what it'll take to make them fit + what tyres would be advisable.

I've got the M sitting on BCR Coilovers; everything else stock.
19x9.5 et22
19x10.5 et 34

Having trouble finding out if there would be any issues. I'm assuming the front's wont work without some negative camber involved.

[CSN327]

Hi guys,

Just got myself a z4m roadster. I'm a huge fan of 166 style wheels (E60 M5 ones), with specs of:
front: 19x8.5 et12
rear: 19x9.5 et28

what is the best tire setup for them? will 235/40 and 265/35 do? or 235/35 and 265/35? I'm looking at ad09 so only 255/30 available if i had to 30 on the rear.

[jp_haus]

Found a set of D-Force rims I'd love to pick up. However, is there a reason why I'm not seeing much info on running 18x9 all around?
Been searching through pages on the topic and seems like something like this would be fine:

Front - 245/40/18
Rear - 265/40/18

The set is a square 18x9 et 41 so I'm thinking worst case scenario I can use spacers to push the tires out to be flush if needed but they should fit, right?

[gutus]

Apex VS-5RS
18x8.5 et40 235/40/18 (5mm spacers)
18x9.5 et22 275/35/18
On Bilstein PSS10

[Auelox]

19" BBS RS GT with Continental extreme contact
Front 19" x 8.5" ET 35 245/35/19
Rear 19" x 9.5" ET 25 275/30/19