CSL tyre size, Need advice please! Particuarly track goers!

[dgm]

I run 245/35 and 255/35.

More grip at the front - less at the rear and circumferences almost identical to the Z4M OE (gearing correct).

That is a good set up, I ran the same for 18 months and thought it worked really well before I messed things up with 275's. I'm happy with my current sizes as well though.

 

[Kasteel]

I have:
225 front
255 rear

no issues here, next time I'll take the 235/265 CSL combo .

 

[dgm]

I have:
225 front
255 rear

no issues here, next time I'll take the 235/265 CSL combo .

I had these sizes very briefly when I put the 19's on and didn't like the narrower fronts which made the car feel a bit twitchy both in a straight line and when cornering. I think you will be pleasantly surprised when you change to the 235's.