Merc Mania

I just spent a half-hour scouring past threads in search of any reports from CLK drivers who use smaller than stock diameter wheel rims on their cars, and I could not find a single such reference.

Pretty much all the wheel rim discussions I spotted centered around the quest to go ever larger on wheel diameter, with quite a few CLK drivers fielding questions about how their cars would handle if fitted with those gigantic 20-inch wagon-wheel rims more typically associated with 1968 Chevy Impala low riders.

I do realize that current automotive fashion trends have ushered in an era of cars riding on ever wider and taller diameter wheels, but complying with the dictates of vehicular fashion trends has never been one of my strong points, particularly if ride quality is significantly worsened by the replacement of stock parts with after-market versions selected purely on the basis of aesthetics.

Cutting to the chase, I would like to find out if it would be feasible for me to replace my stock 18" AMG wheel rims with 16" , or even 15" rims, in order to select tires that will restore the overall diameter of the wheel/tire combination to the stock diameter. Also, to simplify my tire purchasing requirements, I would like to ask the pros here whether I can go with IDENTICAL tire and wheel sizes on both the front and back of my 2009 CLK550.

The rationale for my going smaller on rim size, and thicker on tire size, is primarily due to the very rough road surfaces out here in Africa, where those fashionable 20-inch rims would be reduced to scrap metal in minutes. Also from the standpoint of looks, I have never cared for the gigantic wagon wheel appearance that is all the rage in the car world at present. To this old dog, those monstrous car wheel rims make their barely-visible tires appear deflated, or non existent, in addition to producing a horrendously rough ride, as is reported by those who choose to endure the fashion craze.

Any advice that can be offered regarding the tire size that would work on 15 or 16 inch rims, such that their combined diameter is restored to the stock specification, would be greatly appreciated by this dinosaur who pines for a long lost era. Finally, unless there is a compelling, performance-related reason to retain the diameter/width differential between the front and rear wheels of the CLK, I hope to go with identical wheels and rims on the front and back of the car, for simplicity when it comes to purchasing.

Thanks in advance for any recommendations that can be offered in response to my questions about wheel and tire size.

Yidney

You certainly would not be the first person to go with a so-called "square" set up - meaning the same size at all four corners. MB designs it to be "staggered", but whatever advantages that may have are probably moot on moon-surface roads. You are correct that it would be rare to find somebody looking to go smaller. At a minimum you can go to 17" with no issues because that is what the 550 came with in 2007. Different design wheel, and easy to find used on ebay. Getting them to Africa may be a different question. I really have no idea about 16" or 15." I assume some old C classes or something used 16". But is there even a 15" in the MB bolt pattern? Would it even go over your front bakes?

Merc Mania

I probably will wind up settling for a set of stock 17-inch rims to replace the 18-inch AMG rims that came with the car, but before the final decision, I will try and swap over the 16-inch rims and tires on my W124 E420, to see how they fit, and if so, how the CLK runs on those rims, in a brief road test. The brake calipers on the CLK 550 are massive compared to those on the E420, so it may well turn out that there just isn't enough room in a 16-inch rim, to fit over those CLK brakes.

It is reassuring to learn that a few CLK owners users are running identical sized tires on all corners, with no reported adverse effects, meaning I might get away with such a setup, even if the stock 17-inch rims are the smallest size I that will fit.

Your response is appreciated as always sir.

Rudeney

The CLK550 uses the larger fixed-caliper brakes, and I believe 17 is the smallest diameter you'll be able to use based on the needed inner clearance.

Merc Mania

Recalling the saying that advises reading the instructions when all else fails, I will likely stay with the stock 17-inch rims on this car, when it is finally ready to leave dry dock. The 18-inch AMG alloy rims currently on the car are in good shape, so it may be possible to turn them over in partial exchange when I purchase of a set of 17-inch rims in decent shape.

gaazmon

I'm sure the 18-inch set would be in good demand as they are a very nice set of wheels. The 17-inch will definitely make a difference on the ride. Also note, your vehicle also comes with lowered sport suspension along with the 18-inch rims since it was standard on 2008 and 2009 model year CLK550, so that also plays a role with the firmness of the ride.

sailorben

16" came as standard in the UK and Europe on the CLK, in 205/55r16 and 225/50r16 iirc. My first CLK avantgarde but with standard suspension had this setup.

My CLK has 17" as standard with the sports suspension, however it has the standard brakes, using slide pins, so I am unsure whether the 16" would fit over the calliper on your 550, or not...

However, my 17" alloys still afford a fairly sizeable sidewall. I wouldn't be too concerned.

Merc Mania

Now that is odd. I looked through the owner's manual, and only saw references to 17-inch rims. Thanks for this mention, Sailor Ben. It will only take a few minutes to test the clearance of the calipers in a 16-inch rim, and since I've got a set installed on my 1994 E420 that is parked next to the CLK, I'll run this size test, and share the results here, just in case there might be any other CLK owners who live where the road surfaces are rough.

If my test of 16-inch rims fails, then it is reassuring to hear that the stock configuration of 17-inch wheels still leaves sufficient room for tires having enough sidewall to withstand the odd pothole.

sailorben

My older CLK with 16"


A quick photo of the sidewall on 17"


you could very very well use XL load tyres with a stronger sidewall if you were still concerned.