BMW Z4 3.0si Coupe
Discussion
Deep Thought said:
.... and it turns out you were absolutely right.
Had a spare hour today so got the Z4M wheels out and swapped over a rear. It sat out about an inch past the wheel arches which is just too much for me.
Bugger.
Sorry to hear. Been there myself with a different set of alloys...Had a spare hour today so got the Z4M wheels out and swapped over a rear. It sat out about an inch past the wheel arches which is just too much for me.
Bugger.
Mr Tidy said:
People do run M wheels on non-Ms though, but I've no idea how they get on with possible rubbing issues.
4 front alloys would probably workDeep Thought said:
Yes the wheel rim itself was sitting out about an inch past being flush with the bodywork, so probably closer to 1.5 to 2 inches out beyond how it would sit on a Z4M.
They'll go up for sale now. They've had all the work done - powdercoated, new genuine centre caps, new genuine M badges, matching set of Michelin tyres.
They looked well on my E90 330i (10mm spacers on front) so potential there for someone, but in reality there would be someone with a Z4M would want them. Its just a matter of finding that customer.
Are you sure you're not running spacers somewhere on the rear? I've seen a few non-M owners fitting the M wheels without issue - as in the photo below...They'll go up for sale now. They've had all the work done - powdercoated, new genuine centre caps, new genuine M badges, matching set of Michelin tyres.
They looked well on my E90 330i (10mm spacers on front) so potential there for someone, but in reality there would be someone with a Z4M would want them. Its just a matter of finding that customer.
Also, the M has a slightly higher profile rear tyre (40 vs 35), but both should be the same 255 width.
Edited by C70R on Monday 7th March 08:13
C70R said:
Are you sure you're not running spacers somewhere on the rear? I've seen a few non-M owners fitting the M wheels without issue - as in the photo below...
Also, the M has a slightly higher profile rear tyre (40 vs 35), but both should be the same 255 width.
Nope, definitely no spacers.Also, the M has a slightly higher profile rear tyre (40 vs 35), but both should be the same 255 width.
Edited by C70R on Monday 7th March 08:13
The workaround seems to be run a lot of negative camber on the rear wheels. This disguises it. That might be whats happened there.
Deep Thought said:
C70R said:
Are you sure you're not running spacers somewhere on the rear? I've seen a few non-M owners fitting the M wheels without issue - as in the photo below...
Also, the M has a slightly higher profile rear tyre (40 vs 35), but both should be the same 255 width.
Nope, definitely no spacers.Also, the M has a slightly higher profile rear tyre (40 vs 35), but both should be the same 255 width.
Edited by C70R on Monday 7th March 08:13
The workaround seems to be run a lot of negative camber on the rear wheels. This disguises it. That might be whats happened there.
My Z4 is only a humble 3.0i, but it seems to be running a fair amount of rear camber already. A quick once-over by a specialist in Hampshire (RBM - they know their onions) suggested no bushes were excessively worn, and the collective wisdom of the internet suggests that -ve camber and toe-in on the rear is how they left the factory.
As luck would have it, I parked my car next to a Z4M when it went in for its recent TLC. Mine is running E46 MV1s, which are the same size and offset as the Z4 rims (ET50, 8.5J).
You can see the slight tuck on my rears, whereas the Z4M's wheels sit much closer to flush. I can't see how 20mm of increased offset and 12mm of tyre width is leaving yours sitting an inch proud of the arch. Did you take any photos?
You can see the slight tuck on my rears, whereas the Z4M's wheels sit much closer to flush. I can't see how 20mm of increased offset and 12mm of tyre width is leaving yours sitting an inch proud of the arch. Did you take any photos?
C70R said:
As luck would have it, I parked my car next to a Z4M when it went in for its recent TLC. Mine is running E46 MV1s, which are the same size and offset as the Z4 rims (ET50, 8.5J).
You can see the slight tuck on my rears, whereas the Z4M's wheels sit much closer to flush. I can't see how 20mm of increased offset and 12mm of tyre width is leaving yours sitting an inch proud of the arch. Did you take any photos?
i didnt take pics unfortunately. You can see the slight tuck on my rears, whereas the Z4M's wheels sit much closer to flush. I can't see how 20mm of increased offset and 12mm of tyre width is leaving yours sitting an inch proud of the arch. Did you take any photos?
The flat surface of the alloy wheel itself was an inch out past the bodywork. No spacers.
It wouldnt be a difficult experiment to repeat so when i've time i'll stick the car on the jack, repeat and take some pics.
I'll also get tyre sizes, but it was the rim i was comparing it to, not the tyre so it cant be that.
This was the thread i based my assumption on that it would fit - which is inline with your thinking and experience.
https://z4-forum.com/forum/viewtopic.php?t=108989
I'll find the other threads here saying otherwise that i subsequently found.
Deep Thought said:
C70R said:
As luck would have it, I parked my car next to a Z4M when it went in for its recent TLC. Mine is running E46 MV1s, which are the same size and offset as the Z4 rims (ET50, 8.5J).
You can see the slight tuck on my rears, whereas the Z4M's wheels sit much closer to flush. I can't see how 20mm of increased offset and 12mm of tyre width is leaving yours sitting an inch proud of the arch. Did you take any photos?
i didnt take pics unfortunately. You can see the slight tuck on my rears, whereas the Z4M's wheels sit much closer to flush. I can't see how 20mm of increased offset and 12mm of tyre width is leaving yours sitting an inch proud of the arch. Did you take any photos?
The flat surface of the alloy wheel itself was an inch out past the bodywork. No spacers.
It wouldnt be a difficult experiment to repeat so when i've time i'll stick the car on the jack, repeat and take some pics.
I'll also get tyre sizes, but it was the rim i was comparing it to, not the tyre so it cant be that.
This was the thread i based my assumption on that it would fit - which is inline with your thinking and experience.
https://z4-forum.com/forum/viewtopic.php?t=108989
I'll find the other threads here saying otherwise that i subsequently found.
ETA - Did you drop your car back onto the floor with the M rim on? I can imagine it might look a bit weird in the air, with the suspension drooping - and under compression the top would naturally tuck due to the -ve camber.
Edited by C70R on Monday 7th March 09:48
C70R said:
Funnily enough, my photos of the car wearing M rims came from the Z4 Forum too. I'm on the Z4 group on FB where a few people seem to have fitted M rims without issue.
ETA - Did you drop your car back onto the floor with the M rim on? I can imagine it might look a bit weird in the air, with the suspension drooping - and under compression the top would naturally tuck due to the -ve camber.
Nope, dropped it to the ground. ETA - Did you drop your car back onto the floor with the M rim on? I can imagine it might look a bit weird in the air, with the suspension drooping - and under compression the top would naturally tuck due to the -ve camber.
Edited by C70R on Monday 7th March 09:48
Studied it from various angles. Conclusion was the alloy sat out an inch past the wheel arch.
It had the real Carlos Fandango look going (if you remember the Panama cigar adverts) no matter how i looked at it. The 19 inch CSL style rims sit slightly in under the edge of the wheel arch by comparison.
I'll find time to refit it and take some pics. Wont take long and would be worth getting to the bottom of.
Deep Thought said:
I'll find time to refit it and take some pics. Wont take long and would be worth getting to the bottom of.
The problem is the offset difference of 20mm compounded by the Z4M rim being half an inch wider.It's because the Z4M effectively has the E46 M3 rear axle instead of the regular Z4 rear axle.
Easy enough to verify with an online tool
https://www.wheel-size.com/calc/?wheel1=255-35-18X...
The tire will stick out 20 mm farther. Rim will stick out 26 mm farther
Front Z4M rims fit perfectly on the rear of the Z4 3.0Si Coupe.
https://www.wheel-size.com/calc/?wheel1=255-35-18X...
Rim will stick out 2 mm farther
Seek said:
Deep Thought said:
I'll find time to refit it and take some pics. Wont take long and would be worth getting to the bottom of.
The problem is the offset difference of 20mm compounded by the Z4M rim being half an inch wider.It's because the Z4M effectively has the E46 M3 rear axle instead of the regular Z4 rear axle.
Easy enough to verify with an online tool
https://www.wheel-size.com/calc/?wheel1=255-35-18X...
The tire will stick out 20 mm farther. Rim will stick out 26 mm farther
Front Z4M rims fit perfectly on the rear of the Z4 3.0Si Coupe.
https://www.wheel-size.com/calc/?wheel1=255-35-18X...
Rim will stick out 2 mm farther
C70R said:
Right, and when you look at my picture above, the standard wheels are tucked in under the arches. So that extra 26mm can't possibly result in the Z4M wheel sticking out by an inch unless something else (like a spacer) is at play.
1 inch = 25.4 mm ;-)The Z4M rear axle is 40mm narrower than the Z4 rear axle.
BMW made up for the difference using a bigger offset on the Z4M rear wheels.
The offset difference between Z4M front and rear wheels is effectively 20mm spacer.
Edited by Seek on Tuesday 8th March 10:24
Seek said:
C70R said:
Right, and when you look at my picture above, the standard wheels are tucked in under the arches. So that extra 26mm can't possibly result in the Z4M wheel sticking out by an inch unless something else (like a spacer) is at play.
1 inch = 25.4 mm ;-)The Z4M rear axle is 40mm narrower than the Z4 rear axle.
BMW made up for the difference using a bigger offset on the Z4M rear wheels.
The offset difference between Z4M front and rear wheels is effectively 20mm spacer.
Edited by Seek on Tuesday 8th March 10:24
Either way, in effect I was taking the view of my car (right in the photo above), and trying to gauge where an extra 25.4mm would leave the wheel. It just seems implausible that it could be sticking out by an inch when the top of my wheel is tucked into the arch.
Deep Thought said:
C70R said:
coldel said:
Oi, stop hijacking my car thread!
Apologies! I actually thought the chap asking about fitting the M wheels was the OP!I'll start a thread on the alloy wheel issue when i try again and get more pictures.
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