Well, this question comes up every now and then from various forum members. Most people (including many MB owners) mistakenly assume the C55 is simply a C32 with a bigger engine. I thought it may be useful to list all the differences in this one thread so it can be referenced in the future. The moderators can decide whether this thread could be a "sticky" on top.

This information is taken directly from the MB Press Releases, AMG Private Lounge, and Mercedes Enthusiast Magazine.

Engine:
Almost everybody knows that the C55 has a naturally aspirated 5.4L SOHC V8 rated at 362HP and 376lb-ft torque (North American spec). This is a slight upgrade from the C32's output of 349HP and 332lb-ft torque from a supercharged 3.2L SOHC V6. What many don't realize is that the 5.4L V8 is not very heavy. The official dry weight of the C55 engine is 172kg (~368lbs). Much of the engine is made with light weight alloys, including cast alluminum pistons. I can't find the official dry weight of the C32 engine, but I did come across the following: the 11kg extra weight of the 5.4L V8 over the 3.2L V6 is largely cancelled out by the weight of the supercharger, intercooler and related equipment on the C32 engine. As such, both cars have identical weight distribution (54/46 to 55/45 front to rear, depending the magazine that weighs the cars).

Exterior:
The C55 is the first mass produced AMG to have different sheet metal compared to the standard car. To fit the 5.4L V8, the C55's uses the bonnet, inner wings, and headlamps from the W209 CLK, which means the C55 is the only W203 C-class whose front grille remains with the bodywork when you open the hood, and it is 80mm (3.15 in) longer than the C32. The front outer wings (fenders) are not from the CLK however. The C55 has accentuated arch flares that increase the car's width by 7mm on each side. The front track axle of the C55 is 14mm (0.55 in) wider than the C32. The front bumper/spoiler is from a W209 CLK55, but with new mesh inserts that house circular fog lights. The sideskirts are the same as the C32, but the rear bumper valence now has 2 cut-outs for the twin-pipe (quad) exhaust outlets. The C55 also has a small spoiler on the trunk that generates 14kg of downforce at 200km/h (reduces lift by 30%). The C55 has 18" rims all around, 7.5 x 18 ET30 in the front, and 8.5 x 18 ET34 in the rear, as opposed to the 17" rims on the C32.




Interior:
The C55 (introduced in 2004) benefits from the facelift that was bestowed on the W203 C-class for the 2005 model year. The most notable difference is the instrument cluster, with the C55 having 4 circular gauges, as opposed to the 3 semi-circular or half-moon gauges. The steering wheel of the C55 is a 3 spoke design while the C32 had 4 spoke design. The buttons on the centre console, radio, COMMAND system, climate control cluster, shift knob, and aluminum or wood trim are all redesigned as well. The plastic used in the dash and cabin are of a different texture and grain. Furthermore, the front and back seats are of a new design as well, with the C55 having more heavily bolstered seats for better lateral support, along with Alcantara shoulder inserts to better hold you in place during hard cornering. The pics below are of the Euro versions.




Steering/Transmission:
The C55 has a modified power steering system with a 7% quicker steering ratio than the C32. In addition to the "S" and "C" (or "W") modes, the C55 also has a "M" (manual) mode on the AMG Speedshift 5 speed automatic transmission. In "M" mode, the transmission will not upshift even if you hit the rev limiter, and it will not downshift when you floor the throttle (kickdown). The C55 also comes with shift buttons (paddles on 2007 models) on the back of the steering wheel which allows for manual shifting without taking your hand off the steering wheel.

Suspension:
Compared to the C32, the C55's AMG springs are uprated by 20% (stiffer) in the front, with no change in the rear. The uprated dampers are digressive and have been increased by 30% in bounce and 10% in rebound at the front, and 15% in bounce and 10% in rebound at the rear. The bearings of the front suspension are stiffer to improve steering feel and geometric precision. The elastokinematics were reworked on both axles: Both the tension strut on the McPherson three-link front axle and the spring suspension link of the multi-link independent rear suspension are harder.

Dynamic Control Systems:
Compared to the C32, all of the C55's dynamic-handling control systems, such as the ABS anti-lock braking system, the braking assistant, the ASR acceleration skid control system, and the ESP, were reworked and modified in comprehensive calculations and test drives. For example, the acceleration skid control system now has a traction function when the ESP is shut off. When a car enters a curve at high speed, the system determines when the back tire on the inside part of the curve starts to slip and can brake it to a precisely calculated degree without throttling back the power. The effect that is created corresponds to that of a mechanical locking differential and promotes the traction of the driven wheels.

 

So does all this make the C55 any better than the C32? There is no significant difference between the 2 cars in terms of straight line acceleration, but there does appear to be a noticeable difference in handling. Most magazines show the C55 having higher skidpad grip/slalom speeds.

Of course, the C55 and C32 have never been tested in a head to head manner. But Sport Auto has tested both cars on the Nurburgring and Hockenheim using the same driver (but on different days).

Nurburgring
C32: 8.37 minutes
C55: 8.22 minutes

Hockenheim
C32: 1.20,6 minutes
C55: 1.18,6 minutes

 

Nice write up and if ok with you gonna put a link in my one stop search...

 

PC

Again...excellent info.

 

Nice info. Thank you for taking the time to lay that out.

 

Thanks...Now I've been educated!

 

just out of curiousity, what is the center display, right below the windshield? OP said the cars are euro spec so i am just curious.

 

That's for Parktronic.


Great write up pc!!!

 

Dunno why they didn't offer the different color combos for the C55...I would have loved to have a merlot/black interior!

 

thanks so much for your post!

 

nicely done PCV!

 

Just to update/complete this old thread. Not mentioned previously is that the C55 came with additional rear axle cooling that lowers the differential oil by up to 15 degrees Celsius when the car is travelling at prolonged high speeds or is under very dynamic stress.

Here is picture of the cooling "elements" or "fins".

 

I like you, you're smart, but seriously great write up!!!

 

decided not to try to hijack post.
Great post. Sticky this!

 

Per Frank, we can NOW do this for the C32 with three bolts, he even has a part# for it.

 

hello everybody im interesting can i install C55's nose on the C32 ? fenders hood bumper lights ?

 

The simple answer is no, because of the amount of time + money + effort in finding parts and doing the conversion, but it is possible. Though, if you factor in the cost of all the parts + labor/time, then you're likely better off just getting a C55 (price-wise). Both these cars have depreciated quite a bit now, so they can be had for not too much money, and the amount of money/time you would have to put into a C32 to do a front-end conversion, would be quite a bit more than getting a C55 straight up.

Of course the assumption here is that you can find a C55 that satisfy your requirements (color/price/mileage etc.)