ertimark

Hello,

I just became an AMG 'rookie' 2 weeks ago, bought an awesome '14 C63 Coupe (w204) which needs a wheel upgrade from the factory 18s... Read almost every thread here about the wheel fitment ... However, before I made my big purchase from a dealer, I need a feedback..

The target wheel set: 19" O.Z. Hyper GT HLT (Graphite).
To be honest I spent almost days of reading posts, and I AM SURE that the following fitment would be great below:
F: 8,5 x 19 ET44
R: 9,5 x 19 ET52

The local shop (who will order the wheel set for me) checked the fitment in their database, and according to them I couldn't go with 9,5x19 rear wheels because of the wideness (they advised 8x19 & 9x19...). I had an argument with them, but I haven't got enough proof ... This factory setup is a bit underrated for an AMG.. I would like to go as wider as possible without rolling the outer fenders... (I have stock suspension).

Can you please confirm my opinion? I think I can easily run that setup with 235/35/19 and 275/30/19. What is your suggestion about the fitment? I would really appreciate your help.

Thanks in advance,
Mark

Mort

I have run a 10" x 19" ET +52 on my car. On a stock height car a 275/30/19 should be a good fit. On my lowered 2010 C63 the right rear snicked a bit on dips. I changed to 265/30/19 and used those on my lowered 2012 C63 without issue.

On the front a 8.5" x 19" ET +44 will be conservative and you will be able to run a 10-12mm spacer. A 245/35/19 will fit on the front without issue even with a 10mm spacer.

MBNRG

Mort, you have vast wheel experience.
I have hard track use in mind, and am also looking to maximize wheel width (front & rear) on a FL coupe with stock ride height, without any fender mods (no rolling, etc), and don't want to use any spacers.
Keeping the track use (and other parameters in mind), is the 19" x 10" ET +52 the widest we can safely go for the Rears? Rear Tires will be 275 - 30 - 19.

What dimensions do you recommend for the Fronts (again, to maximize wheel width. no spacers preferred, no fender mods to the Fronts, stock height). Front tires will be 245 - 35 - 19.
TIA

Diabolis

I am running 19x9 ET 40 fronts and 19x10 ET 50 rears (on a Canadian APX car which is 10mm lower than US variants) with MPS4S 255/35-19 and 275/30-19 respectively and have not observed any rubbing under "hard" track use (hard in quotations because my definition of hard is probably different from yours... you can't get hard use with street rubber, period).

P.S. Corrected front tire size... the new fronts are 255/35, not 245/35. It nicely dials out some of the understeer. A stiffer rear sway bar ought to help with this even more, but I do have a purpose-built track rat so the C63 is not the primary track toy.

MBNRG

Doug!
You were the other member I was going to contact. I think your definition of 'hard track use', even on street tires, will be above & beyond 99% of us on here
(Sorry for the thread hijack, OP. This is a golden opportunity to get input from 2 of our most learned members: Mort & Diabolis)
So the new Fronts at 255 are sittin pretty on the 9" width wheel? I wonder if I can go 19 x 9.5" wide on the Front (and keep tire at 245 - 35), given the 1cm taller height on a stock US suspension?

Also, do you gentlemen think I can squeeze a 19 x 10.5" wheel in the Rear on this stock US suspension (with 275 - 30 tire), without fender mods, keeping a safe margin for on-track deflections/loads?
(I know I will have to take careful measurements, etc)

This gives me some hope for a 19 x 10.5" Rear on stock suspension/fenders (don't believe he ever tracked his car):

Mort

I am currently running a 9x20 ET +34 with a 255/30zr20 on the front (unmodified fender) of my car without issue. I have run a 9.5x20 ET +40 with a 245/30zr20. The problem I had with the 9.5 x 20 was with the KWV3 struts the tire rubbed on the lower spring support and I had to run a 3mm spacer to get clearance so I never bothered to try a 255 with that wheel size. The KWV3 lower spring mount is lower than the OEM strut spring mount I believe so the OEM strut may not cause the same issue.

The 245/35/19 has a diameter of 25.75" and the 255/30/20 has a diameter of 26.02" so you should be good with the 245/35 even on a lowered car.

Diabolis

Sorry for the delay MBNRG. Yes, 255/35s fit perfectly on the 9" ET40 fronts.

Seeing as it is USUALLY the tire that ends up rubbing, those should both work assuming that you get the offsets right. With those tire and rim sizes you'd be at the outer limit of the approved rim range for most street tires, but you should be fine. Mort likely has a lot more experience with different sizes and offsets than I do, but when I used to regularly track the C63 I was usually running a 245/35 front of some description on a 8.5" ET36 and later a 9" ET42 rim without problems. The rears were either 265/30 or 275/30 on 9.5" ET50 rims.