Has anyone tried fitting a 275/30-21 on the front of the S-class?

21" tire selection is a bit limited. The next smallest size is 245/35-21 and it is a little stretched on the front rim (Carlsson Ultra-lights 21x9). I tried a 265/35-21 and it rubbed the upper control arm badly.

245/35/21 is the perfect size for a 9" wheel

That was my stock tire size on my Alpina that had 21X9 in front

I mounted a set of 275/30-21 on the FRONT and they fit with no clearance issues. Wheels are 21x9 with 40mm offset. Nice to have the extra meat on the front.

Making them fit is the least of your problems. Your new tires are 1" taller than oem which will possibly screw up the computer especially if you fun a different OD on the rear. Your SRS isn't going to like it. On top of that, your speedo will be off.

R.K.

Stock front tires are Pirelli P-Zero 255/35-20 with a 27.2 diameter.
The Continental 275/30-21 is 27.5 in diameter.....you're telling me 0.3 is going to throw everything off?!? I don't think so.

on a side note. i'm running stock 245 40 18 on the front and 265 40 18 on the rears on my 2004 cl600. is there any advantage, or disadvantage running 235 40 18's on the front with the existing 265-40 18's on the rear?

Sorry. I thought you had a CL65. You posted this in the wrong forum. You should be okay with what you put on.

R.K.