Originally Posted by footie
There is nothing wrong with 19" wheels but only if the car's suspension set-up was originally designed to run with said wheels. The reason why we are even having this debate is the fact that BMW decided to offer the M3 with two differing wheel size options and the reason is as goldminer said namely money, almost everyone will prefer the look of the 19" alloys on the car and are willing to for go a little of the balanced handling to have the looks. The kind of people who keep the standard rims are the kind who are only interested in the performance, the car could be made out of flower patterned Carbon Fibre and they wouldn't care less as long as it benefited the performance, same goes for the rims.
So what I am trying to say is you can only truly optimise a car for one wheel size, so this explains why the CSL was able to run 19" wheels and perform amazingly and yet in the M3 it always felt like a compromise.
The thing is 18" wheels are not an option on the M3 CSL. Only the 19" CSL wheels from BBS that we all know very well. And as far as I know, ( and I could be wrong) the Standard M3 was designed on 18" wheels.
Let's say the following statements are true. (18" wheels perform better than 19" wheels, and the CSL is the performance brand for BMW's M division. CSL owners are more interested in performance than standard M3 owners.)
If it were merely a matter of sacrificing aesthetics for performance, why not give the option for both?
I submit that there is always the exception in every case and I'm hardly an expert, but this one seems to fall right in that category.