Wheels/Tyres help needed

[audi321]

I have just bought some nice original CSL rims for my E46 M3 Conv.

I would like to put my existing tyres on them as they have plenty of life left in them. However, the tyres are 235/40/19 (front) and 255/35/19 (rear) and my local tyre place are saying that they are too narrow to fit on the CSL 8.5 and 9.5 width rims.

Does anyone know if this is true or are they just trying to sell me 4 new tyres???!!

Cheers for any help

[LC23]

I think the proper sizes for tyres on the CSL alloys are - 235/35x19 and 265/30x19. However, I have got CSL alloys on mine and have standard size M3 tyres (225/40/19 & 255/35/19) and they are fine.

[Mroad]

The general rule of thumb for any tyre and rim combo is the rim needs to be 90% of the tyre width with +/-1/2in leeway.
So with a 255mm width tyre:
(255 / 25.4) * .9 = 9.035in ideal rim width. You can also use either 8.5in or 9.5in rim.
The side wall height does come into play when they get very shallow as it makes it harder to fit the tyre without damaging the rim.
It could possibly the problem with yours, they may not want to held liable for damaging the CSL rims although they can be fitted (or as you say they may want to sell you some tyres too!).

You can fit extremely narrow tyres if you want:



But not necessarily recommended unless you're on pimp-my-ride