AMG6.3

Well I just had my winter square setup tires installed yesterday. I went with Michelin X3 225/40/18s all around from tire rack -> great prices!
I had these installed on my stock AMG wheels which are trashed/road rash on wheel lips from the horrible pot holes in MA.


Sorry such as long write up


I have three needs when it comes to new summer rims and tires which I will mount on Michelin Pilot Super Sports:


1) Wider tires in rear
2) Horrible roads thinking 18" wheel setup while increasing tire side wall
3) Bigger tire sizes than stock with all help minimize stock wheel gap without lowering it. I realize by going with slightly larger side wall I am losing grip slightly in the cornering but should offset with Pilot Super Sport summer tires vs. my old PSS all seasons. I also don't track my car.


Question sizing: Given below parameters, what would be the best rim size and offset to sit flush and any concerns with below?


- Front wheel setup thinking 235/45/18 diameter of 26.3 rather than stock 25.4 (increase my sidewall by .46) and decrease my stock wheel gap at the same time wheel size 18X8 with 45mm offset?


- Rear wheel setup thinking 265/40/18 diameter of 26.3 rather than stock 25 (increase sidewall by .66) wheel size 18x9 with 50mm offset?


Thx,
Keith

Roswell

I would go 19's for better look since u are staying at stock height. Aftermarket 18's only looks good/big with the right drop.

But for flushness, I'm running 1x by 9 +40 front with 245 tires.

1x by 10 +50 with 275.. No problem.

I am Jeff

19's won't work for him because he wants to run larger side walls for better rim and tire protection.

AMG6.3

I just found out one of my stock wheels is cracked...looking to have it welded.

CarHopper

How bad can the roads really be? Unless you live in a major city like NYC, Chicago, etc... Otherwise you have to aim for potholes for the most part.

Just keep in mind changing diameter will change your speedo vs actual speed. Very minimal, but still a difference.

Diabolis

You should indeed consider yourself fortunate. In Canada - or Toronto at least - we really have only two seasons: winter and construction. The potholes that open up in the winter are huge, and then during construction season you're driving on and off corduroy pavement with sharp raised edges, raised manhole covers, steel plates and what not. 4" - 6" raised edges are VERY COMMON - as in you'd encounter at least five of them on any random 20km drive through the city.

The roads are so bad that the only time of year when the pavement is reatively smooth is now - after the road repairs have been completeld and before the new potholes open up from the constant freeze/thaw cycles, but running 19" summer tires near freezing temperatures is not without other serious challenges.

Diabolis

To the OP: one other thing to keep in mind when going with AFTERMARKET 18" rims for the C63 is brake caliper clearance. A friend with the same car as mine was shopping for a set of winter rims, and he couldn't find a single set of 18s where the rim spokes didn't hit the calipers. Just a word of warning.

Diabolis

Don't. Replace it.

AMG6.3

Thanks for heads up! I certainly want to ensure they will fit in terms of sizing and offsets.


I can't be the only person one this forum who wanted to run 18s other than stock wheels.

m a x i m u s

i went to school in boston ... the roads are horrible. my car got completely trashed as a result.

+1 about the speedo variance, which will also affect your cruise control, btw.

driftmotion

I'm running aftermarket 18x8 for the winter (all around) with 225/40r18 and have no clearance issues. I think they are sport editions sold by TireRack

johnny--2k

I'm running 275/35/18 PSS rear on stock 18's (which fills the gap quite nicely I might add) and speedo is off by 1 MPH pretty much constant up to 100. I use my Escort 9500 to measure my GPS speed, and my car is always reading 1 MPH lower than what my GPS speed reads on the 9500.

AMG6.3

Good to know but looking for a new set of wheels in the spring.






Anyone running a nice looking 18" aftermarket wheels??? Vendors please advise....

kgmuse

I'd suggest 245/40/R18 (25.72" overall height) fronts and do 265/40/R18 (26.35" overall height) or 275/40/R18 (26.66" overall height) rear.

stock is 25.4" front and 25.03" rear. not sure why mb did that but oh well. roads in colorado suck and I ended up running the 245/275 setup. smooth and great for track days.

AMG6.3

U aren't rubbing with 275/40/18? That is a very tall tire. What offset?

kgmuse

nope rubbed with 285s though on articulation. don't remember offset off hand. too late in the day to think.

johnny--2k

Why 275/40 and not 275/35 though?

the 275/35 gets you closer to the stock size anyways.

kgmuse

it was in stock at the time and rides better with crappy roads. ended up doing well on the track too. I'd like to do 275/35 next time though, less rake look and rubbing chance. so yes forgot the 275/40 and do 275/35

F1BHP

How does the over size affect the cruise control other than the speedo is off?
Are their any other issues with increasing overall diameter like ABS OR ESC?

johnny--2k

none that i've seen so far

Diabolis

A 275-width tire is too wide for the OEM 9" wide rim. You'd get too much tire squirm during hard cornering (especially at the track), which does upset the car's balance. You're much better off sticking with a 255 or a 265 at the rear. In terms of grip the extra 10 mm is pretty much negligible.

johnny--2k

agreed, for hard track driving that would be a bit much. but for spirited street driving, the chances of pushing the car hard enough on the street to notice are slim to none, and I may track my car once or twice a year if even that much, so that was a negligible side effect for me.