y didnt tthey put the new engine in fir 2012

Mark my words the c class will never see that engine, unless it's a special edition black series.

it would have been too fast with the tt motor.

It goes against Mercedes strategic plan. The new 5.5 TT will be present in the higher end AMG cars first, then will slowly trickle down to the E and eventually the C, after a few more years probably 2013-2014 time frame. Think about it this way, why would Mercedes put the 5.5 Bi-Turbo in their less expensive model for 70K, when they can offer the same engine in their 150K cars? If you could get that engine in an AMG at a cheaper price, would you not buy it? The M156 isn't going away anytime soon, in the C63 platform. This is a good thing for the aftermarket, and benefits all of us with C63.

I guess we were lucky this time around that AMG shared the same engine (except V12).

I've been telling others in other threads that the 5.5 Bi-turbo isn't coming to the C63 and they didn't believe me. I just they'll believe me now

Its all about the cost. They never brought the 55 kompressor to the C-class. But the 6.2L is shared with all the classes. Even the SLS. Personally I Don't like FI.

It may very well get a bi-turbo, more like the 4.6 litre they now offer. Eventually, the 6.2 will go the way of the dinosaur and a smaller displacement engine will replace it in the C Class. The numbers on the 4.6 are not that much lower than the current C63, so its possible this will be the engine for 2013 C AMG. A lil tune here and there and that engine could easily put out numbers to match or exceed the 6.2. I can see a 480 HP C Class AMG on the horizon.

The new 4.6 liter V8 comes with twin-turbocharging that delivers 435 PS (429 bhp / 320 kW) and 700 Nm (516 lb-ft) of torque.

The 5.5 Bi-Turbo will eventually make it to the C63 eventually but in a detuned version, imagine a C63 with 580 hp same as a CL 63 with a performance package, and costs only 70K.

Or they might just go with a NA smaller displacement motor.

I am admittedly surprised that the 'new' C63 isn't getting the 5.5tt motor.

If I were to hazard a guess, it would be that:

a.) The new motor is too expensive to put in the C63. A new engine would certainly be more expensive to make than the old one since new tooling and whatnot will be needed (specially considering the C63 is more of a volume seller than the others). And that's not even taking into account items additional to n/a V8's - things like intercoolers, turbos, valving and plumbing required (most of which will be x2). This would make the C63 too expensive and perhaps put it out of the competition.

b.) Heat. With turbo-charging and all that, you'd need to get rid of a lot of heat. There's a lot less room under the hood of the C than in the CL, S or CLS.

and finally,

c.) If the tt is in an ordinary C63, they would have nothing left to put in the BS other than a V12. Which would probably be a bit of an overkill. But would be a fine thing... if not a little nose-heavy...

Not only that, but the turbo motors are built with beefier rods, pistons, cranks, etc. so they can benefit from boost - unlike the current 6.2s.

Am i the only one who loves the N/A 6.2? I had an E55, & if had to choose between N/A & FI, i would definitely go with N/A. And yes, i know we can mod a FI engine much more.

There are a million possible reasons why they didn't do it, and I doubt anyone on these boards really knows. It could be any of the reasons above or it could be that some tiny widget supplier no one has heard of cannot make enough widgets for all AMG platforms to get the 5.5tt. In reality, the decision was probably a combination of things. However, I prefer to think that it is a well-planned, strategic decision to keep the sportiest AMG models (C class and SLS) with NA powerplants.

Whatever the reason, I am glad they kept the 6.3 in the C class, because it is the best motor. (The MCT is a big improvement, although I don't think it is the world changer that a lot of people seem to think it is.)

No, you're not - but there are advantages and disadvantages to bot setups. On a roadcourse / trackday car, I prefer NA. On the street, on long highway pulls, at drag races, at mile events, etc. there is nothing like a turbo motor.