Where did you get the data? I personally don't believe it. There are lots of variables in weight measurements for cars. Let's get this sorted out. Some of the variables that come to mind are: full tank/empty tank, spare/no-spare, with driver etc.
Supertest quoted C55 at 1680kg = 3703 lbs, but you can be sure that wasn't empty. It would be what they consider to be a true "test weight". I know Norm weighed his C32 at an actual 3600 with 1/2 tank ready to go (no driver).
The C55 has bigger wheels, longer nose, bigger motor, (less supercharger weight), bigger exhaust, rear deck spoiler. I don't see anywhere they actually saved weight. I guess the C32 is the lighter one by about a little, maybe 40-50lbs.
You can drive your C55 to a scale, only costs about $3 max.
Take the spare out of the C32 to be fair as I am sure both cars are weighed with their spare installed. That will be good for about 50lbs minus the number for the space saver spare.
More importantly, look at the increase in front and rear track which should help in the handling department. There is an increase of 13mm in the front, and 10mm in the rear, which is just about what my aftermarket wheels and tires have equaled. I will have to think it through, but it seems that the wider track should cause additional wheel/tire clearance issues with both the front and rear fenders upon a wheel/tire upgrade for the C55. Does this increase in track set the hub mounting surface out towards the fender more causing the stock 7.5/8.5 wheels with 225/245 tires to sit in the same orientation as upgraded 8.5/9.5 wheels with 235/265 tires? Remember one inch is 25.4mm, so the increase in track is about .5", or half the wheel width increase of the upgraded wheels, which represents the same increase out towards the fender if you split the 1.0" total wheel width increase between the inside and the outside. Food for thought...
I've read 2 road tests here and both said the C55 is lighter, but not by much. Both magazines tested the C55 faster than the C32. The one did a comparo between C55, S4 and M3 on a track. Guess what - they chose the C55 overall!
actually, im not surprised that the C55 is lighter... The motor is definately lighter!!! The Kompressor weights a lot on the C32... the C55 motor weights just as much as a C43 motor.. its the same block with different bore and stroke!!!
C55 - 3,540 lbs/1,605 kg
CLK55 - 3,635 lbs/1,657 kg
C32 - 3,605 lbs/1,635 kg
I thought that the C55 would weigh more. guess i was wrong
From multiple sources on the net, I've seen the curb weight at 3,540lbs not 3,605lbs. From specs, you would think the C55 would weigh more, but you never know. I'd like to check the official manual statement on this...