dbturbo2

test drove a '10 E63 today and was really interested in comparing the MCT tranny to the DSG in my Audi. I was trying to do double downshifts by pulling the left paddle twice as I do on my DSG but could not get the car to execute a downshift of more than one gear. Is this normal or did I miss something?

MBStar

You may have to select the Manual mode to accomplish this. My preliminary
impression is that the MCT is not as good as the AUDI s-tronic gear box that I tried on the TT.
I need to do a bit more research but I think it was on this forum
someone posted that the MCT is basically the 7-Gtronic minus the torque
converter.

I am sure 220S knows, is the MCT a "doubble clutch" variety or not?

220S

Okay

The AMG Speedshift MCT is a standard planetary transmission automatic gearbox but with the torque converter replaced with a wet start up clutch.

The AMG Speedshift DCT on the new SLS is a true dual-clutch semi-automatic transmission.

Hopefully the DCT will find its way into the E63 eventually.

MBStar

Thanks 220S. There you have it! This is a lesson for wannabes like
me not to trust the slick MB salesmen who insinuated that the MCT was a
"dual clutch" transmision "like the Audi's, only better ('cause it 's MB!)".
I noticed only after a few weeks of use that it did not fell like the "DSG", but
did not have the heart to really find out and get upset
Now we know the ugly truth....

The anoying thing is that the MCT, in any mode other thatn M,
has a variable response to one "click" of the downshift paddle.
It will downshift by as many gears as it feels necesary, and this is largely
dependent on the throttle position at the time. so if you want to downshift
by two gears, just step on the throttle a bit more, and if by 3 geats, step a
bit harder. Or...go to M mode.

Wonder if 220S also knows a bt more about the OP's functional question?
How is this MCT better than the old "7-Gtronic"? Thanks

dbturbo2

thanks guys, fantastic info that explains my experience. I drove a C63 after the E63 just to compare the trannies and the E63 shifted significantly faster (as it should) but it still felt slower than my DSG (as apparently it also should).

I too was lead to believe the E had the same tranny as the SLS, now I know better

Forgot to try but wondering if I had pulled and held the downshift paddle in manual mode if it would have downshifted automatically to the appropriate gear like it does on the C63?

220S

afaik, no coupled torque converter with the newer MCT like there is on the 7G-Tronic. The MCT is hooked up to a wet mechanical slip controlled start up clutch instead of a lockup clutch (making it apparently even better in terms of eliminating slip between pump and turbine.) Same bell housing, same planetary set, just different clutch setup. But it'll feel more direct (and better fuel economy.)

fwiw, here's the DCT in-depth (scroll down to DCT section):http://www.emercedesbenz.com/autos/m...ower-transfer/

And here's the MCT in-depth (scroll down to 'power transfer' section); it also describes exactly how the MCT is supposed to work in the real world: http://www.emercedesbenz.com/autos/m...ower-transfer/

Maverick1975

I have AMGs with both gear boxes and in both i can downshift more than 1 gear by simply pulling the downshift paddle and holding it down. If your in 5th on hwy and to get a bit lusty, just pull and hold down instead of releasing paddle and you will be in 2nd before you know it, then release (obvioulsy downshifts faster in SL vs ML and C but works with both transmissions).

bushburninc63

So does it work like the C63 transmission by just holding the left paddle down for a second and releasing it. This action should shift it down to the lowest safest gear as stated by Maverick?

MBStar

Thanks very much for that and the links.

MBStar

My understanding of the OP was that he wanted to do down shift one gear at
a time, and to be at all times in control of the down shift process. That in
any case is what I miss in any semi or full automatic mode with MB.
If you pull the left paddle and hold it there is no telling where the transmission will
end up - yes you might be in second gear but might also be in third,
depending on where your throttle is and what your rpms are.

The functional result is that in spirited driving, I find the 7Gtronic down shifts too low,
and I end up overreving the engine, having to lift of the accelerator, losing valuable
seconds and track standing.
Thankfully they have the M now, that allows me nearly full control of the gearbox.

dbturbo2

thanks 220s for the links. So DCT shifts "in less than 100 milliseconds" and the MCT "in 100 milliseconds". It's curious that both are described as having a similar if not almost identical double declutching dowshift capability. Still makes me wonder if the MCT acts like the DCT on double clicked downshifts.

In manual mode, does the MCT adapt to driving conditons and vary the shift speed accordingly or does it shift at conistently at the same set speed regardless?

europeankar

I wanna trade in my 10 C63 for the 2012 C63 MCT. I am very concerned about the shifting time. Does it react like F1, PDK, MDCT, S tronic, etc??? Like when I am cursing at 100km/h then suddenly I pull the downshift paddle - two times. Will it bam bam very quickly? I really dislike the 7G on my C63.

Nstar

This is all true but the SLS transmission still does react like a true semi-auto in manual mode, it feels more like an auto, though I've only had 15 minutes of non-track wheel time this was quite noticeable. Not as bad as the 7G of course, but Benz still need time to get this right. Perhaps their too concerned with keeping it smooth through the software (and wanting a seamless auto mode) which may be the hindrance as the pieces are all there.

The optimized 6.2 in the SLS is so impressive and if they can perfect this trans it the car will be even better.

sideeffects

I've also noticed that if you hold the downshift paddle on the e63 in manual mode it will **** down to the "safest gear." However, I don't feel the shifts are aggressive enough.

When cruising at 80 MPH if you hold the shifter down the car will drop into 4th gear. The problem is dropping into 3rd would give harder better acceleration. I usually hold down the shifter to drop to 4th and then hit it a second time to get into 3rd. I miss the tranny on my SMG e60 M5

Vic55

The MCT is faster than your conventional 7G but its not as fast as the DCT in the M3 or in a GTR... Im guessing the MCT is around 100ms and the DCT is closer to 80ms or 20 percent faster.

europeankar

This sounds pretty bad already. New C63 uses the same MCT You missed the SMG jerk or

europeankar

The "S", "S+" and "M" modes deliver increased agility through fast, responsive gear changes and higher revs. Gear changes in the "S+" and "M" modes take just 100 milliseconds.

Is MCT really that bad? It's making me not going to get the new C63.

Vic55

I like the MCT, well in regards to what Benz has to offer on their models (sans the SLS)- its better than any slush box tranny they have. Some say it does rob the car of power more than the standard 7g tranny and this may be true but there are other functional parts that I like- Shift speed and throttle blips come to mind.

But it doesnt come close to firing out the gears at high reving/higher speeds like the DCT in the M3 or the tranny in the GTR (Ive owned the M3 and still own a GTR).

The shift from 7 to 3 is relatively quick and its actually smarter than my GTR tranny which will place me in 6th gear at 30 mph (when cruising) for no reason (all auto mode of course). In manual the DCT is better.