kleroo

the setup, wheels.
My 2016 CLS has the sport wheel package. 18" rims 255/40 Front and 285 Back.
I think it is silly for a 220d, with 170HP and 400nm. Even hardcore sportscars don't have these wide tires.
And I don't really feel any useful extra grip in the corners, compared to the very stock 245 wide ones.
But I love the rims. SO! plan is: Put 245/40 R18 front. That is the real perfect size for it.

Question is! What to put in the back on the stock 9.5" rim. Calculator says that a 255 can be fine. I would go with the narrowest. 255/40 R18 is a fine size.
265 width...is out of scope. /35 would be smaller, and 40 would be bigger then stock size. 275/35 can be a good one, but only some tires are available in this size, and not much narrower then the 285....

Generally doe anyone know why MB put this wide tires in this narrow rims? It only leads lazy-loosen-spongy agility.

Serhan

I was wondering also about OEM wheel selections after seeing the tirerack video as below. I assume manufacturers are trying to minimize the wheel weight by going the smallest option per given size for OEM.

www.youtube.com/watch?v=1MDq23scaWw

kleroo

Just saw that as well, couple of days ago.
my issue is, that a wider rim is not much heaver...if it is. But wider tyres are always heavier. A 245/265 setup would have been an optimal stock IMO.

Question is still open, how this stock 9.5Rim would look with a 255 tire.