Another wheel advice request - CSL wheels...

[NickF]

Hello all, I recently traded in my Z4 Coupe 3.0si for a Z4 M Coupe, and I had some questions regarding wheels. I do not like the wheels that come on the M at all, and actually really preferred the look of the wheels on my 3.0si. There are like a thousand different wheel threads on this site, and I found answers to some of my questions, but some of the data seems to be conflicting.

Before I start, I just want to point out that I am in no way an expert, and don't really know half of what I am talking about.

I have been looking at possibly going wider and maybe a larger diameter as well, but I am very concerned about causing any rubbing. I do not want to modify anything to put on larger wheels. Also, I don't want to add a bunch of un-sprung weight by going with larger wheels (though I have always wondered how much weight you are really adding when you go up in diameter... I know your wheel may weigh more, but won't the tires weigh less?). In addition, I don't want to change the circumference of the tire (not sure what the tire term for this is - rolling radius or something?). I really am not sure I understand offset and all that either, and have seen the offset calcs that people have posted links to, but not really sure what to do with them.

Anyway, my questions...

1. It looks like from the searching I did on the forum that the widest that you can go is 8.5" on the front and 9.5" on the back. Is this correct? When I plug my car into tirerack, they list wider wheels available, so I wasn't sure.
2. Will the CSL wheels that I keep seeing on ebay and other places that are 19" x 8.5" and 19" x 9.5" fit without rubbing? I saw some people posted that they would and others reported rubbing (http://www.z4-forum.com/forum/viewtopic.php?f=2&t=29456&p=401681&hilit=wheel#p401681). Also, does this make the ride really rough? I noticed some people mentioned that, but some said it was fine.
3. Does anyone know for sure what size tire to go with to keep the same tire circumference if I was to go with the CSL wheels I mentioned above?
4. I have seen prices ranging all over the place for the wheels. I figure they are all replicas. Are they all the same or are there a bunch of difference brands with differing levels of weight/quality?
5. My M Coupe is black, and I would love to see what other people have done with their black coupes regarding wheels - I have not been successful searching this forum to find the pictures I am looking for. I have been toying with the idea of blacking it out, and pictures of black vs silver CSL wheels would be great. I am leaning towards CSL wheels because they can be purchased inexpensively, but am open to other wheels as well. I think my favorites thus far are the MORR VS8.2's but I am not trying to spend $6000 to shod my car with new wheels/tires. Although I would love to see if anyone has a black coupe with black VS8.2's.

I am sure all these questions have been definitively answered in one thread or another, but after several days of searching on and off, I haven't found any....

And lastly, I just wanted to say I don't have any pictures of the car yet. I bought it over the weekend, and I work in DC and live in Atlanta, GA, so I am in DC for the next two weeks and won't be able to take pictures until then. Although I do have pictures of my old 3.0si coupe.

This forum seems great, I look forward to being a member (after I take my pictures of course). Thanks...

 

[dgm]

I won't go into great detail but here's my thoughts on the matter. I'm assuming that by CLS you're talking about CSL, I know there was no M3 CSL in the US but the wheels you're referring to came on a competition spec M3 if I'm correct. I've run my car with genuine 19" CSL wheels for 5 years now, they went straight on to the car with no modifcations whatsoever. They are lighter than the OEM 18" wheels by a noticeable amount although I don't remember the exact weights, so you're better off when it comes to unsprung weight. Genuine CSL's come in 8.5" front and 9.5" rear.

There is definitely no rubbing caused by the change in wheels when running on 265/30/19 rear and 235/35/19 front. I've tried other combinations and for me these are the best sizes to go for. That will very slightly change your rolling circumference but not to any extent that you have to concern yourself with. Your speedo will still read slightly over as they are designed to do from the factory.

Personally I don't have any issues with the ride on 19's, I've always run them on either Michelin PS2's and now Super Sports and don't find it an issue. I think it's an over emphasised point to be honest but others will disagree.

I can't comment on replicas but I imagine they will all be heavier than genuine CSL's by some margin.

Here's my car with graphite powdercoated wheels.

 

[NickF]

Thanks for the response man... And yeah, I meant CSL... I guess I warned that I didn't know jack. Anyway, I do really like the look of that. Thanks for the info and the pic.