I need tire size help anyone with C63 AMG wheels
 

I have a 2009 C300 4matic sport, last year I put on C63 AMG wheels and tires. The rears are 255 35 ZR 18 and the fronts are 235 40 ZR 18. These clear no problem, BUT I need new tires and was considering getting the C350 SPORT size. The rears are the same but the fronts go to a 225 40 ZR 18. So they are a hair narrower and a bit smaller diameter. I figure less splatter on the sides of the car. Has anyone put that size tire on a C63 AMG wheel? Does it work or are they too small for the rim width. I do not know what size the rim is. Spring is coming and I need new tires. Thanks for the help.

225/40/18 will fit front wheel and is the correct size for the c350. 235/40/18 is only for c63 amg.

The rims are the same size. Save a few bucks and go with the 225 tires, the C63 has 235's probably for the weight of the beast under the hood. However, I did notice a little less understeer when I had the 235 up front. But when I buy new tires this spring I'll probably buy 225's. Slightly less sidewall for looks and slightly less weight for the real world.

Here are the rims specs if my memory serves me.

Optional 18" for C300/C350
8.0 x 18 ET50 225/40
8.5 x 18 ET54 255/35

C63 18" wheels
8.0 x 18 ET45 235/40
9.0 x 18 ET54 255/35

Search the C63 forums, the tire sizes have been address a billion times. I just went through this with my 19s i just put on my C63.

I already have the C63 amg wheels and tires that came on the C63. I am just wondering if downsizing the fronts will be ok with AMG rim. So based on what Krytech says the rims for the C63 and the C350 are the same size?

AMG CATALOG 2010
C-CLASS
AMG light-alloy wheels
Styling vi, painted titanium grey, high-sheen surface,
8.0x18 ET45, tyre size 225/40, FA only B6 603 0098
9.0x18 ET54, tyre size 255/30, RA only B6 603 0099

The fronts are the same size, only different offset

so a smaller tire on the AMG wheel mounted up to a C300 wont look any different than the bigger tire

The fronts are not the same size. The C350 runs a 225 and the C63 runs a 235 front. I have C63 AMG wheels with 235's now they run and look fine, just want to know if the 225 will be noticeably smaller. Does anyone have a picture of a C350 with the 225 40R18 Tires? My C300 with stock rims and tires does not look that good, the front fenders stick out way past the tires and makes the car look smaller.

ok found out the 225 tires go on 7.5" rims and the 235 tires go on 8" rims. So I am sticking with the 235's

The 7.5" wide rim you're referring must be the 17" OE wheels?

The 17" specs are:
7.5" x 17" ET47 225/40
8.5" x 17" ET58 245/40

However as I mentioned above, the optional 18" front wheel is 8" wide, exact same as the C63 front wheel.

A 225/40/18 tire will fit any rim between 7.5" - 9" inches wide. Typically the measuring width is 8" so you're just fine using a 225/40 on either the OE 18" wheels or the C63 wheels.

Whoops! The 17" fronts are 45 series!

Yes, good catch! The front tires are indeed 225/45 on the 17" OE wheels.

Thanks!! :y

The other important thing to note is that the suspensions are not the same for the C350 and the C63, so ride and stability are the result of different geometry to the center of gravity. Brake differences between the two models are also equally important.

So, if high speed driving, car dependability, and riding comfort are concerns, I suggest that the wheel change be thought on its scientific effects merits to parallel the Charlie the Tuna commercial, you don't only need a wheel that looks good, you need a wheel that also gives you a safe ride and sure stopping power at any speed, on any road.

Godspeed.

So does that means we should go with 225 and not 235:nix:.

I don't want to speak for him but I don't think *that* was his point. His point is an important one though and one that I think gets over looked when I see someone slap huge wheels/tires on a C300 with out addressing the brakes.

The minor difference in centrifugal-force between a 225 & a 235 tire is relatively minor. But the difference between a 17"x7.5" wheel with a 225 tire and say a 19"x9 or larger wheel with a 235 tire up front would be significant and would certainly show up in the cars stopping distance and would likely make the ride a little more ruff since the suspension is going to be working a lot more.

Front235 n Rear255

i have the 225/40 18 fronts on my c350 sport

And the rear's look smaller ???? is that because they are 35's and not 40's

Wise choice. Either size will fit but the 235's will protect your rims. I find even the 255's on the rear are too small and am on my second wheel refurb from gutter rash so will go to 235 and 265 on my next tire change.

they do look smaller in pics huh.... but, i've already changed my rear tires to 265/35 18's same rims just changed the tires. i'm hoping to replace them with the ones that are from the e350 sport. they look the same but only half an inch wider up front and in the rear.

I would have stayed with 40 as to have more meat on the sidewall ....

in the picture it looks as though the wheels should be switched because of the meatiness of the front's sidewalls ...:nix:

the original tires were 255/35 18 that's actually what you see in the pics. i don't have a pic of the car now with the 265/35 but it does even up the tire height to the fronts.

like to see

i'll try to take a pic and post it asap