E55 or C55
 

E55, most people go from the N/A platform to the supercharged ones. Yes lots of members have done coilover conversions, you just need some rear non-airmatic upper control arms I think. Depends on how well your car was kept, some need a few k just to get general maintenance up to par.

As an owner of an E55. Def a E55.
But if money and maintenance is an issue the C55 is def the next best option.
Honestly since the car is older now, it isn't much expensive to keep the airmatic suspension .

Are you looking to mod the car? If not, I'd also consider the W211 E63 as well.

Don't be scared by all the hoopla about M156 as the issues didn't effect every car. They also sound much better than the M113K.

Test drive them both, you'll feel the difference and end up getting the E55. That's what happened to me. No regret.

I owned a C55 for almost 3 years before I sold it and went to an E55. The E55 is more comfortable/spacious and feels like it's built to a higher quality, but I do miss the handling of the C55, although I don't regret the change. Maintenance wise for the C55, it was just mostly wear and tear items, especially at the mileage (I bought it with 120k miles, sold at 143k). Belt, pullies, fluids, valve cover gaskets, brakes, control arms, tie rods, engine mounts, etc. The starter died on me and the alternator died a month after I sold it, but nothing out of the ordinary. For the E55, it has been pretty solid so far (almost 1 year into ownership). Engine mounts, ball joints, trans service and some other stuff was done prior to my ownership. I've only done an oil change so far, and have a few more things I'd like to do before spring but again, nothing out of the ordinary. Luckily no issues so far with my Airmatic, fuel pumps, SBC and pano roof. IMO I would not do the coilover conversion; I like the flexibility of the air suspension. If I wanted conventional suspension I would have just kept the C55 :y

I had a C55 for a few years and 6 months ago bought an E55 thinking it will be a direct replacement. I was wrong, now I don't know which to sell. Both cars are amazing with the C55 being significantly underrated because it doesn't have a supercharger. If the C55 came with a M113k from the factory I doubt as many people would have gone for the E55. Probably going to keep them for a few more years before I decide. I also have long term concerns with the E55, the airmatic will cost over $2000 to address with parts alone at some point. SBC will go out, just a matter of when. The C55 will require just wear items.

The C55 feels like a much sportier car in comparison to the E, steering is more direct and has more feel, the brake pedal is much more responsive and can be modulated better (SBC on the E55 is not for performance) and the regular suspension feels much without being too firm. The acceleration on the C55 feels quicker at low speeds because it can actually hook in 1st gear, I feather it off the line and WOT by about 10mph, pins you back in the seat for entirety of first gear unlike the E55 which requires feathering the throttle all through 1st gear. At lower speeds around town and back country twisty roads the C55 is the clear winner.

The E55 on the other hand is great highway car, the engine turns much slower due to the 2.65 rear end (vs 3.08 on the C), the airmatic is in its element in comfort mode, larger interior and better seats make themselves apparent. Don't get me wrong, the E55 will carve corners with the best of them, it has all the grip in the world but the feel of the steering and brakes doesn't inspire or excite you to keep going faster and faster until you find the limits and go past them. Big difference in torque due to the supercharger, the E55 has lots and LOTS of it. Rolling on in fifth gear @ 60mph rockets you forward like a downshift would in the C55. On a backroad the corner exits on the E55 feel downright insane, 2nd gear has heaps of torque from any speed, even a dead stop and scares passengers into silence.

The C55 looks like a small fast car, big wheels, big brakes, quad exhaust pipes and a ride height that already looks lowered. The E55 is menacing with it's huge brakes, even bigger tires, bigger exhaust tips and the overall size is much more imposing. The W203 looks a bit narrow in the rear. The ride height on the E55 is dependent on suspension settings and does look lowered in sport 2.

My E55 came with a stack of previous maintenance records but @ 80k miles I ended up spending another $2000 on control arms, engine/trans mounts, guibos, ball joins, intercooler pump before I could enjoy it. The C55 in comparison just needed brakes and engine mounts after I destroyed them at the drag strip, about $500 so far in maintenance. I spend another $1500 putting on headers and other exhaust mods, bluetooth stereo (no factory phone or music bluetooth on 2005 C55, the 2004 E55 only has phone bluetooth) and a few other things odds and ends. Haven't started modifying the E55 but will probably do 80mm pulley, long tube headers, auxillary heat exchanger and tune hopefully landing near 600 crank hp and 700 torque.

The E55 does have some major limitations when it comes to cooling that compressed air and on warm days you won't get to experience all that the M113k has to offer. If you get on from a dig up to 100mph the intake air temp will reach over 100f, this is where it begins to pull timing. Keep it pinned till the end of the 1/4 mile and it reaches over 140f, pulling timing as it rises turning your near 500hp car into a 400hp heat soaked slouch.

I love both cars and would rather have these two than any newer car on the market. If I could only have one I would pick the C55. It's a bit better on gas (14 vs 16mpg), much more reliable (no SBC, no Airmatic, no supercharger and it's cooling system) and more fun to drive.

I agree with all of that. The w203 C55 and w209 CLK55 are pretty much the same when it comes to performance. They are awesome all round cars but a lot of owners were always chasing more power. The handling is ok for the C55/CLK55 but neither are even close to a proper sports car. I don't regret the upgrade in the slightest. The comfort and power of the E55 makes for a truly special driving experience.

I find this statement disagreeable. The C55 is a very underrated car. It's handling is right on par with the sports cars of the time. It ran an 8:22 around the Nurburgring. You know what else ran an 8:22? E46 M3. Here's some other cars for comparison:

8:13 --- 150.43 km/h - Mercedes C63 AMG, 457 PS/1761 kg (sport auto, 02/09)
8:14 --- 150.12 km/h - Mercedes SL 65 AMG, 612 PS/2049 kg (sport auto 01/05)
8:15 --- 149.82 km/h - Corvette C6, 404 PS/1491 kg (sport auto 08/05)
8:22 --- 147.75 km/h - Mercedes-Benz C55 367 PS/1605 kg (sport auto07/2004)
8:22 --- 147.75 km/h - BMW M3 E46, 343 PS/1584 kg (sport auto 12/00)
8:23 --- 147.44 km/h - Porsche 996 Carrera 4, 300 PS/1466 kg (sport auto 01/02)
8:25 --- 146.85 km/h - Porsche Cayman S, 295 PS/1412 kg (sport auto 11/06)
8:29 --- 145.69 km/h - Mercedes Benz CLK 55 AMG, 347 PS/1593 kg (sport auto 05/00)
8:32 --- 144.84 km/h - Lotus Exige, 192hp (sport auto 08/04)

Nurburgring in my mind is a great way to show the overall performance of a car, not purely handling. It has long straights and high speed curves. Notice nearly all of those cars have pretty high HP as well. I could destroy either of the 55's in question on a tight road course in my 28 year old mr2 which is N/A.

You don't really think a C55 handles better than an exige right?

Nurburgring in reality has plenty of tight sections and cars with lower power output have been able to thrive and set record times. Lets take a peek at the the front wheel drive class, the current Civic Type R with 300hp runs around the ring in 7:44, same time as the C6 Z06 with 505hp and Nissan GTR from 2010.

Your original statement is that the C55 is not even close to handling like a proper sports car. It's track times reflect that it's able to go around the track like a proper sports car and faster than some purist cars of the time that didn't even come with floor mats, like the Exige. Yet the focus of the C55 isn't to set record laps around race tracks, it's a daily driver, only available with an automatic which just happens to handle as well as the sports cars of the time.

Apparently the C55/CLK55 is so underrated that even it's owner don't know what it's capable of.

I have watched a few in car video's of the track so I guess we will just have to disagree, I think it is a high speed track requiring some decent (not excessive) power to really get good times but I haven't analyzed the data in much detail. Yes 300HP in a light car, once again.... power. Once again why the 192HP exige you mentioned isn't higher up the ladder. I have driven my old CLK55 on tight mountain roads plenty of times, I even put coilovers in. It is a great car, it excels in more things than most other cars at the time but it isn't exceptional at any of them including handling. I only mentioned it as I don't think it is right to give someone the impression this will be a good fill in for a tight winding road with the miata, Porsche, mr2 club.

The 05 and up W209 and W203 AMG cars got a host of improvements that made them better handling cars, your basis of comparison is a car with a different suspension calibration and less direct steering rack. In the company of Mr2s and Miata's one would get bored pretty quick behind the wheel of a C55 on a twisty road, Porsches are more along the lines of equals. W209 lacks a B pillar, because of this the W203 chassis is stiffer.

8:25 --- 146.85 km/h - Lotus Exige S, 243 PS/940 kg (sport auto 06/08)

The C55 could only do 4.9 seconds to 60 and 11 seconds to 100 yet somehow manages to pull away from the track focused Lotus on a race track.

Maybe I am wrong, in my experience the tighter the course the less power:weight ratio matters. Sorry I don't care enough to trawl through data to prove my point. If you think the C55 is as good as any light weight sports car with ideal weight balance and tons of lateral grip that's fine. I am convinced they are a fantastic grand tourer. I am interested to hear what everyone else thinks.

I think that the C55 was underrated and undersold. It's biggest performance downfall being the automatic transmission not the handling. In spite of its shortcomings it's a very capable car that is rarely considered as a performance alternative to the E46 M3.

Airmatic can be switched over to BC coilovers for like 1400, probably less if you shop around, and an issue with airmatic doesn't mean you need to drop 2k and replace everything.

SBC now has a 25 year unlimited mile warranty. Got another 10 years until you'll have to pay for this :y

I don't think losing adjustable ride height, automatic active damping and stiffness setting at a push of a button is worth the savings, it will be expensive when the time comes but I wish to retain full functionality. As far as the SBC, I know there's warranty but like everything it follows Murphys law and will happen at the worst possible time, the dealer will take a few months to fix it, during which my airmatic will spring a leak and my 12v battery will die. That's just how it goes sometimes.

For the cost of ownership and maintenance, I would say the C55. But for exclusivity the E55 can't be beat for power and grace.

E55 hands down!

You won't regret it!

As the owner of a C55 (my daily for the last 15 months/26k miles) I have a bit of familiarity with them.
A C55 will destroy a G35/370Z in a straight line and will give them a hard run in the twisties.The handling part is stymied by Mercedes refusal to allow cars to turn in. MB is well known for designing vicious understeer into everything they make (SLS/GT excepted). I autocrossed my C55 at a fast course. The car refused to turn in. I was doing all kinds of trail braking and other things to get the initial response but it wouldn't happen. Once the car began to turn it was great. Slow in and fast out was definitely the name of the game. My opinion is that the front suspension is oversprung. If I was going to autocross it regularly a set of front struts and springs from an 05+ C230 Sport would go under the car. All this being said, there's no way an E55 with similar tires will turn with a C55.
My car has received shorty headers and an EC tune, each purchased on sale for $250. It will run a 13.0 in the quarter. Not fast by today's standards but still a ton of reliable fun. From a stop I roll into the throttle taking about 1-1/2 seconds to go from idle to WOT and the car just goes. There is a respectable amount of torque everywhere in the rpm range.
The C55 is the best bang for the buck in the entire AMG lineup. You simply will not get more performance per ownership dollar. So far, I have needed nothing more than tires, a rain sensor, and a heater circulation pump over the 25k miles I've driven. I beat the crap out of my car (I visit WOT daily) and the car doesn't seam to care.

Now for the downside...
I find myself constantly looking at other cars with more power. In fact, I was exploring the E55 forum today to see what kind of reliable power the M113k makes with bolt-ons. You see, I'm a hot rodder at heart and am dying to stuff more power in the C55. Swapping in a 113K with the associated electronics/reprogramming is not something I find intimidating. The lack of easy power adding mods is disturbing. A fast C55 is slower than a stock E55.
Standing 6' tall and squishing the scales at 230 lbs I find myself cramped in the car on long trips. I bought my car in NJ (cleanest C55 I could find in the states) and drove it home to DFW. I have since made a few long trips. Each time I do, I find myself looking for more interior space. I have an upcoming trip from Dallas to LA this summer. As much as I enjoy my C I do not want to drive it that far because it's too small. Despite saying these things, I do not have any problems in my 23 mile (45 minute) drive to work. Driving 23 miles home after a day in the dealership is no hardship either. Still, I'm seriously contemplating getting after the engine rebuild for my 1972 Chrysler Imperial so I can sail it to LA at 15 mpg instead of flashing there in a much smaller 23 mpg C-class.

I'm ready to give up the quick reflexes and response of the C55 for an E class with a 156 but surrendering the reliability and low cost of ownership is hard to do.

I drove both during factory press introductions (including hot laps of Hockenheim) and have owned an E55 wagon for two years and 20,000 miles. Both are immensely impressive, but the C is lighter, hence more nimble and fun to drive on a curvy road. The E is bigger, heavier, has more space, and needs a heavier hand on the steering wheel. Both are great bang for the buck. Truth be said, I rarely use the full power of the E55. I came from a W124 E320 wagon with 500E suspension, which was slower but lighter and more agile than the E55 wagon. If I could change anything about the E55, it would not be to increase power but rather to decrease its considerable weight. I also drove a C43 AMG wagon in Europe (never imported here) and loved its great combination of handling and power. You won't go wrong with either car.

off topic, but I'm literally saving up to import one as soon as they're 25 years old. I will 55 swap that thing before it even gets off the truck, and it will be my new daily.

Sulaco, make sure you drive it for a while before you decide. It's extremely well balanced and fun to drive as-is. Maybe I should look for one now...