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2006 CL600 2011 C300
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Discussion Starter #1
I have read damn near every post I could find about the correct offset to run on these cars.

But as everyone knows... different size/brand rims tend to change the game.

I have found quite a few offest 'calculators' online and some 'charts'.

But, oddly... they do not seem to compliment each other so that is the issue.

Factory I think as most of us know is 44 front and rear.

I am looking to run 8.5" wide in the front and 10" in the rear with a 20" rim.

I'm not so much worried about tires as I will pick a set that will still fit within the wheel wells limits and the front/rear suspension components.

A chart tells me 35 front and 43 for the rear and these are spec'd by Carlsson and Brabus respectively.

So... can anyone say for SURE if these are within the correct specs for this car?
And... please tell me what you have on your car if you are ridding on 20's.

Thanks for any insight...
 

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8.5" front ET 44 mm will be fine. 10" in back needs with an ET 44 mm should be fine too. Make sure the wheels clear the caliper or they will need a spacer and may will end up sticking out from the wheel well.
 

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With 20" 8.5J wheels on the front the correct ET is 35 and the tyre should be 245/35R20.

On the rear ET 43 with 275/30R20 tyres.

The front ET can vary from 35 to 43 but the rear stays between 35 and 43
 

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Discussion Starter #4
OK, I am not so sure I could run only 1 mm off from factory.

Are you absolutely positive this is correct? When I did some measuring on my car it just didn't add up that I could use a 35 on the rear. Tire would be sticking out way to far past the fender well.

Or at least this is my findings.... But again, if I knew for sure... I would not be asking...lol.

So.. anyone else care to chime in here or at least confirm the above info?

Thanks guys.
 

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Discussion Starter #6
I have looked over that chart but that conflicts with other info I have seen/read and other charts.
I was hoping for a person who has actual knowledge on this car for certain as I hate to buy wheels just to find out that one chart was not correct.... yet another one was.
 

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I just went through this on my W220. Obviously, the goal is to avoid getting stuck with a very expensive set of wheels that don't work. Sadly, even if you find someone running wheels you like that they swear "work", there's a good possibility they aren't as particular as you may be about avoiding unwanted changes to the ride or handling.( I love the guys on the W220 forum with 20's who claim they fit perfectly, they just can't put five people in the car...)

The process I used was to work forward from a known approved wheel configuration by Mercedes itself. In your case I checked the biggest wheel/tire combo approved by AMG for your CL 600 (not Carlson or Brabus. They may be fine, but you KNOW the AMG specs are right)

AMG has specs for your car up to 19", so for your 20's you need a Plus 1 size calculation. Tires factor in at this point, because it's important to keep the overall wheel diameter with the 20's as close to the overall diameter of the 19's. (The difference will be in a shorter tire sidewall and a taller rim).

It is recommended that your new wheels not exceed the overall diameter of the stock approved wheels by greater than 3% to avoid premature brake failure and speedometer calibration issues.

This will give you a set up that matches AMG specs in every way but with 20"s rather than 19's. That means the wheels will clear the brake calipers, won't rub inside on the strut, won't rub outside against the fender lip, and won't alter the load on the suspension components or push the alignment out of spec.Your CL will be very content.

Reference AMG Staggered 19 specs:

Fronts:19X8.5 44mm offset, 245/40/19 Tire
Rears 19X9.5 46mm offset, 275/35/19 Tire

The next step is to find the Plus 1 sizing that most closely matches the overall wheel diameter of the factory spec 19's. There's a handy calculator at 1010tire.com that lets you play with sizing until you get as close as possible.

Here's a "safe" staggered 20 set-up for your CL 600

245/35/20 Fronts (Only 0.15% diameter difference over approved 19's)
Tread Width 9.64 (Identical to the approved 19" tire's width)
Recommended Rim Width 8"-9.5", Offset 44mm (45 ok too)

275/30/20 Rear (Only 0.31% diameter difference over approved 19's)
Tread Width 10.82"(Identical to the approved 19" tire's width)
Recommend Rim Width 9.5" - 11", Offset 46mm (45 ok too)


This will give you the look you want, but doesn't alter the car's suspension geometry, because the overall dimensions of the wheels themselves, or the position of the centerline, haven't changed. Your car will be none the wiser.

(Personally I'd get the 19" approved AMG set up and lower the car an inch to fill out the wheel wells, but that's just me. 20's ride hard.)

When wheel shopping online...

Finding a set of used AMG 20's would be ideal. In addition to those specific to the CL, OEM wheels from a 2000 and up S Class, and 2008 and up C-Class, including the C63 will also have the 44/46 offsets and fit perfectly.

If online replica wheels are an option (I have a set...love them and they were inexpensive) ignore the fitments in the listings. Most replica "AMG Style"wheels are a 35mm offset, but there are 45mm wheels out there that fit correctly.

You'll also want to confirm a 5x112 bolt pattern and a 66.6 hub bore.

Good luck!
 

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You seem to be very knowledgable regarding the fitment of wheels for the CL Class.

I have a chance to get some 20x8.5 rims with what I gather is a 40mm offset. I can't get a clear consice answer form the seller on that. Would I need a spacer to get back to the 44mm factory spec? I have an 02 CL55.
 

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You seem to be very knowledgable regarding the fitment of wheels for the CL Class.

I have a chance to get some 20x8.5 rims with what I gather is a 40mm offset. I can't get a clear consice answer form the seller on that. Would I need a spacer to get back to the 44mm factory spec? I have an 02 CL55.
Right. The 40mm rims would be 4mm closer to the inside (brakes, strut) of the car than the factory wheels. I would test fit them before adding spacers though...they may be okay as-is. If not, you'd be looking for 5mm spacers (I don't think anyone makes a 4mm spacer). I recommend H/R Track spacers. They're expensive but well made. Don't forget to buy a set of lug bolts that have an additional 5mm in length if you end up using spacers.)

8.5" is really skinny for a 20" wheel, and 40mm is an unusual offset for MB. Are these OEM wheels and if so do you know what it came off of? You can also verify offset by asking the seller to measure the distance from the back of the hub mounting surface to the inside (back) edge of the wheel.
 

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They are aftermarket for sure. They are currently on a W140. He said they were off a diffrent model MB so I know at least the BC is correct. 40mm does sound goofy to me too. Like I said I can't really get a good answer about it, I don't think he understands what I'm trying to tell him about it.

I figure the factory stock AMG's in the rear are 9.5" so souldn't be too bad at 8.5". I had some wide 20" on my W140 and it gave me issues in the back so I'd rather not get too crazy, plus the price is right.
 

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They are aftermarket for sure. They are currently on a W140. He said they were off a diffrent model MB so I know at least the BC is correct. 40mm does sound goofy to me too. Like I said I can't really get a good answer about it, I don't think he understands what I'm trying to tell him about it.

I figure the factory stock AMG's in the rear are 9.5" so souldn't be too bad at 8.5". I had some wide 20" on my W140 and it gave me issues in the back so I'd rather not get too crazy, plus the price is right.
The AMG specs for 19" on a W140 are identical to the W220 (44 front, 46 rear) but there's no way of knowing what the other model MB they were from. If they're priced right, I'd grab them and take my chances. Dump them on eBay if they won't work.
 

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Right. The 40mm rims would be 4mm closer to the inside (brakes, strut) of the car than the factory wheels. [\QUOTE]

I think it is the opposite. 40mm offset (compare to 44mm) would be 4mm coming outside toward the fender.

You can also verify offset by asking the seller to measure the distance from the back of the hub mounting surface to the inside (back) edge of the wheel.
Offset should be from hub mounting surface to the middle of the rim.




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I think it is the opposite. 40mm offset (compare to 44mm) would be 4mm coming outside toward the fender. [\QUOTE]

Yes, that's correct, my error. Thankfully it's been a while since I had to deal with W220 wheel issues.

Offset should be from hub mounting surface to the middle of the rim. [\QUOTE]

I may be wrong here too, but I believe the center or the rim would be the line of reference, and the offset is how far in either direction (positive or negative) the mounting surface is from the center.
 

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something you have to consider in this scenario is the abc suspension and how it keeps a relatively flat ride height (despite added weight or handling)

like someone else mentioned, a car with conventional struts and large rims wouldn't fair very well with a lot of weight. although i think an abc equipped car would handle this a lot better

i run 275 30 20's in the rear and never had any issues with my abc system installed(even with a full car). after i switched to a conventional suspension set up however i get minor rubbing in the plastic wheelwell when i have a car full of people and do abrupt maneuvering

edit: the width of my wheels is just right because if you look at how the tire would go up into the wheelwell on a heavy bump or dip, instead of hitting the body paneling (not good) it tucks right inside of it
 
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