I see a lot of different threads and posts about the alternative tire sizes and fitment options when it comes to the W212 4MATIC yet not many seem to specify with the 18s. Most just try and upgrade to 19s.
Well, Simple question really. Was wondering if the tire size on the CLS 550 aka 255/40/18(F) and 285/35/18(R) will fit without issues on the E550 4MATIC with the AMG wheels 245/40/18 OE.

 

Probably doesn't get discussed much because it's not a good idea. You're going to have a .1 inch variation between the front and rear tires. 4matic usually has the same tires on all 4 corners, different sizes may damage the 4matic depending on the amount. Also the speedometer will be off slightly due to the larger tire size. You won't be able to rotate the tires which means the rears will give you half the normal life.

 

While I understand the fact about the tread wearing, I've heard as long as the overall diameter is within 1/10" of the overall diameter of OE tires, nothing would really be affected. Is that not true?

 

Not really sure it doesn't really get mentioned what an acceptable amount is, but some amount is allowed for. But if you're already starting at the outer edge of what's allowed and then you have uneven tire wear between the front and rear, it's possible you'll be out of spec at some point, but you won't know that until you have issues with your 4matic.

 

No it will not. You may squeak by with the 255 up front, as people have mounted them with some success. The 285's are way too wide to mount on an 8" wide OEM AMG wheel.

 

So it's not really about it being 4Matic since from what I can see, the CLS 4matic had those exact sizes staggered. But more of the wheels that I currently have won't fit 285s. Do the CLS have different width wheels at 18"? What would be the proper way to get these to fit? Get the same wheels but at 8.5 in the rear? Maybe 9?

 

I doubt that the CLS came that way stock. Probably done by the owner or it's not 4matic. No E550 4matic ever came with staggered wheels, only RWD models did that.

 

Weird. Everytime I look up the tire size on Google from multiple websites, I get the same results. Staggered 4matic setup. Anywho. I know the e550 didn't come stock staggered. I understand that completely. But I was trying to make my setup staggered and just need to know how exactly to go about that since the CLS tires won't fit in the rear as is.

 

Yeah found another post that basically says it can work, just with 19s. So I'm assuming the width of the 19s help with making 285s possible. Some say they were taken from the sl550 and some say the e63. Either way they were placed on the E550 4matic. I just wanted to know if there was anyway to do it without changing rim size. Maybe rears at 275?

 

I am running a staggered setup with the OEM E63 AMG 19” wheels and I am running 285’s in the rear. The wheels are 9” and 9-1/2”. 245/35-19 and 285/30-19. .1% difference.
My car pictured below

 

Verrrryyyy nice setup there. So you went with the 19s. I see alot of setups like that with absolutely no issues. That's gonna be my second option if this doesn't or can't work for whatever reason. My question now is...would something like 275s work? Or 265s? And for the fronts...is 255 the widest you can go without running during turns? At 18" anyway

 

Ok, well if you want to go down in width in the back (275,265) you will need to play around with the front tire width (245,255) AND aspect ratio. 255/35, 245/35, 265/35,256/30, etc
in a calculator such as this:

https://www.miata.net/garage/tirecalc.html

you need to keep the rolling differential from front to rear as close as possible to avoid 4Matic issues. Keep playing with that calculator to find the right combination. Several MB 4 Matic cars come with staggered setups including the E63 AMG. The version of 4Matic in those cars is different from ours. It is designed to distribute a different front-rear bias.

just be careful to keep the rolling rates from front to rear as close to 0 as you can. I have had my staggered setup for 8 months of the year for 4 years with no issues at all.

 

Thanks....thanks a bunch for that. My only question now is, how wide of a tire will fit on the 8" AMG wheels I have? Because I can play with the calculator but...if the wheels can only fit up to a certain width...alot of it will be for naught. Since I'm hearing 285s won't work....will 275 Even fit? Just need to know the max size on these wheels and then I can play with the numbers

 

Recommended tire widths for wheel width is all charted on the web and easy to find. Start there. I’m not going to tell you as lots of people push these limits in both directions every day. You will need a good tire guy to help you with finding the proper tire that meets the sizing specs, but also the proper load index. Mercedes sedans have a substantial tire load index requirement and that needs to be followed. Generally 97 XL
I think I misspoke earlier regarding the wheel width of the base 18” AMG wheel. It is 8-1/2”, not 8”.

 

Alright I'll do some research and see what I can come up with. Didn't know about the load index. I'll have to look into that. Alright, 8.5 at least gives me a little more wiggle room. I'll report back with findings. Hope to find some sort of answer or resolution so anyone asking the same question in the future, or randoms that are here from a Google search have an answer.

 

Also, definitely didn't ask. How wide can the fronts go before rubbing occurs when turning? That's probably the best place to start a d then work back from there. The fronts will determine the size of the rears.

 

the first place to start is wheels. Once you know which wheels you are going to use, then you pick the tires.

A 285 on a 8.5 will bulge badly and will not look good. It will also allow the tire to move side-to-side on the rim and cause an unsettling feeling from the rear of the car every time you turn. Too wide, not safe.

I run 245/35r19 in front on 8.5" +32 wheel and 285/30r19 in the rear on 9.5" +39 and my rears rub ever so slightly over major bumps.

Also, the 4matic system(except on AMGs) uses all open diffs, so having a small variance in size will not cause any damage in the long run. Staying within 1/10" is sufficient.

 

Thanks for the input. Reason I say I'd start with the max width, is because I planned on sticking with stock wheels. Seeing what I could get out of them. If the widest I can get is like 255 or 265 then I'd look into either larger wheels or wider wheels. Or possibly just run 265 all around. So I'd need to know what the widest is that I can run up front. And if you say 285s rub In the rear with 19s, then that's doable.

 

Bump. Just looking for max tire width for the front.

 

Bump

 

Okay, then go to tire manufacturer website and do research on tire widths and what wheel sizes they fit and what is recommended.

 

Thats just the thing tho, all I've been doing is researching. But I think everyone is misunderstanding my question. I get all the other aspects. All I'm trying to find out is what is the widest tire I can have up front...not for a given wheel size ...but for clearance issues. No issues when turning or over bumps etc. Because yes certain wheel widths can handle certain tire widths but that wheel well can only hold so much up front. 255 is max on a 8.5 wheel I've seen, yet will 255 rub at all in the front? Can't find any answers. That's more specific to the w212 than it is wheel sizes. Not sure how much can fit without modification. As well as what offsets and things like that

 

No, you are the one with the misunderstanding. Different wheel offsets will have different maximum tire sizes as you are changing where the wheel sits inside the available space. Wheels that have the most centered position in relation to the turning center point of the steering geometry will allow for the greatest width. A 255 might fit without rubbing on one wheel, but might run on another wheel, of the same width, but having a deeper or more shallow offset. So, like I said, FIRST you need to pick a wheel, then you can figure out the max width of tire that wheel can sustain on it in the given space. If you want "the widest tire possible" this is not something someone can tell you with the given information. Custom wheel and tire fitting is not just simple math. Tires are made in "standard" sizes, but that dimension is an internal measurement and has very little to do with the outer dimensions of a tire. They are shaped differently and will have completely different outside dimensions (same sized tires)from tire to tire, even different tires made by the same manufacturer. You can't be completely custom and use someone else's formula without following it to a tee. Custom work costs custom money...just saying...

 

And I get that. So forgive my 'partial' misunderstanding. But you're sticking more with wheel size and how even tires from the same manufacturer can be different. I was referring to the 8.5 OE wheels that I already have up front. That's why I said with the 8.5 up front I heard a 255 is max that can fit. I didn't mean on any given 8.5 wheel only a 255 from any tire company can fit. I've looked on this forum and saw that with the OE AMG wheels, the widest they could fit was 255 up front on a W212. Am I wrong for stating that?? I understand there are so many factors at play when it comes to 'custom' tires/wheels....but my thing is, I was asking before the need to go custom...what is the widest I can have on my OE wheels? Aside from those that are modded...or built in different countries...majority of our w212 are the same inner wheel well dimensions...so I'm sure there is some general consensus to the widest tire size one could go before having to think about rubbing/changing wheel size. I was only considering changing the wheel size once I read about 285s fitting with 19s. I'm just still trying to understand how wide i can go up front on stock wheels..just a general guesstimate based on at least some personal experience....like if someone were to say, oh I saw a guy who got some cinturados to fit at 265 up front with rubbing on hard bumps.....that would at least steer me in the direction of alright, maybe 255/265 would work out alright...time to figure the rest out. I'm not going to be able to get all options, I understand that. There's just too many. But I was wanting to know more from personal experiences of people on this forum. As one member stated above...thanks for that. That really gave me an option there. I don't expect one to have all the answers....I guess I just expected more answers in general because most seem to automatically upgrade the wheels. I like the OE wheels. Just wanted to know what's the widest most have seen or can go on these AMG wheels. If I made it seem more convoluted than that then I apologize. I wanted to know my options for wheel sizes and tire sizes without modifications. And then saw the 285s and even heard of some running 295/305. Became interested in that but saw it was with 19s. So in sticking with the 18s I wanted to know if there were any wheel/tire options to go wider without any issues. Simple as that. I apologize for any other misunderstandings or misleadings.

 

alrighty then. I run a 245 up front on an 8.5" wide wheel with +32 offset. Tires are very close to fender liners when turning(inside and outside), but do not rub. I could not fit a 255 on my wheel as it WOULD rub(about 1.5-2.0mm clearance to liner when turning, 2.5-3.0mm from inside of fender lip)