Originally Posted by unagi1

Alright, so I tried this out -- coasting to a stop from various speeds and different modes (s,s+,m), either at a stop sign or coasting to a red light that turned green, etc...then going 100% throttle.

The good news, at least from a consistency standpoint:
The lag is definitely there, but none of the stalling or bucking reported. A good second and a half of no response, then car jumps into action.

The bad news (for those frustrated with the issue):
However, this is not how I drive the car which explains why I have never a) ran into this issue or b) perceive it as a problem during day-to-day driving.

Prior to 2011 when I picked up the E55, I'd never owned a car with an automatic/MCT/etc. Drove a manual trans mr2, 2 cobras, 335i, etc. A few had lightened flywheels, some had turbos at high boost whose power delivery would punish you if you stomped on the gas any where in the rev range. At any rate, I always rolled on the throttle just out of habit. Lots of track and SCCA Solo events have taught me the same way.

From a gas pedal point of view, I am still driving these cars like they have 3 pedals -- and I didn't even realize it until I saw this thread.

1)Green light turns red and I need to turn left? Step on gas slowly until wet clutch engages, wait for car to pass and then increase gas
2)Coasting to stop light that just turned green? Foot on gas past dead-pedal threshold, then hold until gas needed to keep going
3)Coasting stop at stop sign? If uphill, keep gas on pedal like you would when holding revs and letting clutch slip with left pedal. If downhill, just use cars' momentum to keep revs up and roll onto throttle from point of engagement.

This car in particular does not like sudden throttle inputs at low speed, and I have been able to get around it by constantly getting to the correct threshold on the gas pedal for it to keep the trans engaged and not stalled.

Originally Posted by PeterUbers

You'll get the bucking if you aggressively stop and them jump on the throttle before you come to a complete stop and go wot ... Then it stumbles into first gear ... Even 2015 owners have this issue, including 14 s63 coupe and sedan owners

Oh well, like you, I drive the car with a slow roll out and then get on it and I have gotten used to it and I can continue to love this car... But hopefully Benz will one day have a dsg or pdk like trans for this car and eliminate this stumbling and lag

So the 507 has it too??

Originally Posted by unagi1

507 has the same lag when you slam on the gas at low speeds, same tests as E63S. To be clear, I can't repro the stumbling in either vehicle. Cars are either lagging or taking off like bats from hell.

Originally Posted by kart125

I was able to reproduce the lag with above technique (almost coming to a stop then stepping on it...) it works 100% of the time. Knowing that it's a "normal" behavior built in the transmission makes it A BIT more acceptable. A software update would be welcome...

On another subject the car stalled on me again last thursday in stop-go traffic but this time I noticed a bit more what happened. I think the "ECO mode" is responsible for this issue and not the transmission: was coming back from work, stop and go traffic, comfort mode/eco on, distronic on. Slowed down to a stop, engine stopped but car ahead started to move at the same time so engine started about a second after shutting down and stalled... I tried to reproduce it (stepping on gas a second after car stops) and it never reoccured. Seems like a random problem... Anyone experienced this?

Originally Posted by unagi1

507 has the same lag when you slam on the gas at low speeds, same tests as E63S. To be clear, I can't repro the stumbling in either vehicle. Cars are either lagging or taking off like bats from hell.

Originally Posted by PeterUbers

What do mean "stalled" when your engine woke up out of Eco "off engine" mode?

1) pressed the accelerator pedal and no matter how much you push it nothing happens? Until you let go completely of the pedal and re apply pressure

2) engine died

3) pushed accel pedal and took a second before it responded to any input

Originally Posted by kart125

option 2... engine died. Had to restart with start-stop button.

Originally Posted by PeterUbers

By "stumbling" I mean it's jerky into first gear almost like a bad stick shift driver who engages the clutch a bit too fast into first gear when accelerating from a stop

Originally Posted by Geiss

Coming from an owner of a 2015 cls63 s, I also have significant throttle lag.

Originally Posted by Geiss

I certainly don't want to disparage this particular car, I still love my merc. Honestly after I wrote that and drove my car *thinking* I had throttle lag, I realized what it really is, is low early torque. Admittedly the throttle response is immediate it's just the torque below 2000rpm isn't enough to match my ego. So I don't know if a sprint booster would help as much as a tune would. When I tune my car I'll update.

I like jack rabbit starts, and merc has ensured we don't get that for the sake of fuel consumption I'm sure.

Originally Posted by kart125

option 2... engine died. Had to restart with start-stop button.

Originally Posted by benyl

happens to my wife all the time. It's dangerous.

Originally Posted by a4_turbo

My feedback on the Sprintbooster is that I love it and made my 2010 E63 fun to drive. I've always been annoyed by the throttle response in this car. In fact I was almost about to keep my four cylinder turbo and trade this car in when it came to get an SUV a few weeks back. I installed my Sprintbooster about two months or so ago when the temps in Texas were still in the mid 80s and I had it switched to GREEN throttle response. Both my wife and I could feel a significant difference even in C mode. Recently - with temps in mid 90s and humidity galore I've started to become annoyed by the throttle response again. I had to check to make sure the Sprintbooster was working again. So I decided to set it ot RED and OMG - the car just goes now - It's especially fun in C mode since it uses 2nd gear for slow speed cornering or driving. So less jerk than S or S+ and the throttle just responds to the smallest depressing. At least that's how it feels to me. And it made my exhaust sound louder. Trying to understand why the latter effect.

And as a final statement for this post. Before switching it to RED I was almost forced to drive the car in Manual. It does provide the most control over where you are in the powerband but I'm still a clutch guy and find it weird to drive all the time with paddles. that's why I prefer to keep it in C/S/S+ and when needed use the paddle shifters to drop few gears.

Originally Posted by Vrodman

Thanks for this post. I currently have a SB on backorder. Should be getting it any day. I have a 2011 with the throttle lag issue. I find it quite annoying. My 2000 E55 did not have this AT ALL.

Its almost dangerous at times, as it lags so you step on it a bit harder and then all of sudded it lunges out of its shoes unexpectadly. In certain aggresive driving situations this is a problem. That is why I am hoping this SB solves the issue.

So I hope I am as satisfied as you are.

Thanks again.

Originally Posted by cadeca

Hi Peter, came across this thread when searching for info on the Sprint Booster. I have one on my SLK, but am hesitating after reading through the experience with the MCT. Do you still have it installed?