ShaneN.

Hey guys, I have two questions regarding a 2012 C63 with 29k miles I'm likely going to pick up tomorrow and I know you guys will have the answers.

First, I notice from a low speed or stopped the car seems to hesitate from down low. Not badly like there is an issue , and it pulls real hard as the RPM climbs, I just expected a bit more instant down low torque. I had a 2011 for a summer that had a full headers back exhaust and a custom tune so maybe this car just needs a tune but the car didn't seem as fast as I remembered. This is a non performance package 2012. I know it's hard to get an idea of what I'm talking about and my passenger didn't seem to notice but I thought this motor would make gobs of torque off idle almost. After a split second and certainly from a roll it seemed strong/normal.I tried to put traction into sport thinking maybe it was robbing down low power to stop wheel spin but sport didn't seem to make a difference. . I also think the MCT quick/smooth shifts makes how fast it's moving kind of deceiving too.

And also, as I'm coming to a stop the last few feet of slow speed coming to the halt feels kind of jerky or notchy. Almost like something is engaging or disengaging, does this sound like the "jerky" MCT trans everyone talks about? It almost feels like it's lurching/shuttering slightly, again, not something my passenger could seem to notice from the passenger side.

I'm curious to what you guys think.

silverstar11909

Yes the difference between what you drove with headers and tune will be much faster then a stock 12 period... almost 100 hp at the crank. Which is why it felt slower... even with the tune, I don’t feel it till about top of 2 maybe 3rd gear

Also yes the 2-1 jerk is mainly a issue with everyone

ShaneN.

I should clarify, I assumed it would be slower with less power but I didn't think I'd notice so much from a dig/low RPM. I guess that just means it'll need a tune.

The 2-1 jerkyness is something I likely wouldn't notice after a while, just wanted to make sure that was normal.

Mort

The 2012 has a clutch which does not allow much slip from a low rpm or a stop. When you accelerate the revs have to build into the power.

The PFL had a torque converter which unlocks at low rpm or from a stop. When you accelerate the revs build immediately into the power zone at 2500 rpm and you are off.

zcct04

In addition to the 100hp gap (a no-brainer) and the transmission differences (which I didn't know about), two other things can contribute to the slow start. Make sure transmission setting is S or S+, which both start out in 1st gear (vs C which starts in 2nd gear). Also watch the Traction Control light - even in Sport mode you can get some timing pullback when the car detects tire slip.

ShaneN.

It was in Sport and sport plus, what is the difference between the two? And is it hard on anything to always run in sport modes versus Comfort as long as I run comfort on the highway? Maybe even easier on the clutches starting from 1st vs 2nd? I'm more wondering about always being at a higher RPM around the city when not in comfort, although it never seemed to hold it all that high when just cruising anyways.

I was just thinking that it also might have had something to do with getting used to how the previous owner was driving it too. Maybe resetting the adaptives or whatever they're called.