Splaktar

I described the issue that I'm seeing a bit in this thread (https://mbworld.org/forums/gls-class...ml#post8907883). But since it was a bit off-topic for that thread, I decided to start a separate thread here.

I took my GLS into service yesterday for some interior/exterior ceramic protectant and PPF. While there, I got to talk to the service foreman and take him for a ride to demonstrate the behavior.

He did the first test drive, and there were no issues. This was because, from a stop where Auto Stop turned off the engine, he would very slowly apply the gas pedal and speed up the vehicle to around 10 mph. He did that about ten times, and it was perfectly smooth.

Then I explained how it most often happened when I was in a center lane turning left or at an intersection where I needed to get out into traffic in a limited window of time. The 1-2s delay in power delivery would often cause me to miss that window and have to wait for additional traffic to clear. I explained how this was sometimes dangerous, as it would either leave me hanging in traffic or jolt me forward, too late, into traffic after the window closed.

So then I drove, and after a couple of tries, I was able to reproduce it repeatedly.

1. Slow down enough for Auto Stop to occur.
2. Press the gas pedal about 30-50% in order to get moving quickly.
3. The first 1-2s, nothing happens.
4. Then, the GLS lurches forward roughly.

He explained that this was working as designed. He spoke about a lot of details of the 48V starter/generator. It all made sense, but no matter how much sense it makes from an engineering standpoint, it doesn't deliver the performance that the driver needs/wants.

I explained that one of the key reasons you would want a powerful V8 engine is so that you could fit into these semi-tight windows in traffic that require quick torque-on-demand. I also explained that it's too hard to reach down and hit the button right before doing one of these maneuvers in busy traffic. So I now understand why so many MB owners either hit the button to disable Auto Start/Stop every time they start the vehicle or code it off by default.

I don't see this behavior when I'm in HOLD mode and hit the gas.

For the next few weeks, I'll try to see if I can either accelerate slower in these situations or utilize HOLD mode in these situations. If that doesn't work smoothly, I'll become another one who always disables Auto Start/Stop when starting the vehicle.

z28lt1

I'm not sure if your is how all operate or not (haven't noticed in mine, but haven't tried your example much) but as a suggestion, if you need the "powerful V8" for your traffic situations, drive in sport mode. It will turn off the auto-stop, and you'll get more power at part throttle anyway....

Splaktar

Thanks. I will give that a shot as well. So far, I've used Comfort mode 95% of the time. I'm still learning how to best utilize these different modes and how they impact the driving experience.

wildta

Ask them to reset the adaptation for throttle and transmission and see if that fixes it. It takes some time for the system to learn your driving style again.

jkaetz

If the 2024 comfort mode throttle/pedal curve is anything like the 2021, you want to configure the individual driving mode for sport drivetrain and comfort everything else. I have a hard time applying the power smoothly and quickly in comfort mode precisely because it delays the throttle for a second or to. This is fine if you're being leisurely but if you do wish to accelerate quickly, it's annoying. Sport has a more direct throttle curve and is very easy to modulate and accelerate quickly. The downside is that it also delays upshifts longer than I'd prefer but the driving experience is better IMO. Ideally I'd like the sport mode throttle curve and the comfort mode shift points. Don't know if the coders can do that or not. The difference can be felt even with auto stop/start turned off. Stop/start just exacerbates the problem. Side note, sport mode does not disable stop/start on ours.

z28lt1

Good thoughts here. Keep in mind, can always hit the paddle if you desire a sooner upshift.

Had to check because I don't get the engine to stop in sport mode -- The manual does confirm that auto start/top is still enabled in sport mode -- so I believe my 63 is different than the 450/580 (so, sorry about the information above that is not correct for the OP). The AMG supplemental which is only the differences has a section on auto start/stop but makes no mention of which modes it works in. Interestingly enough, the AMG supplemental manual says that if the engine is stopped from auto stop it will restart if you hit the left paddle. This is not in the regular GLS manual, so I imagine another 63 specific thing, but worth a try.

MDMercedesGuy

If you're trying to make gaps in traffic regularly where you are having to use 50% throttle, perhaps you need to also be looking at your personal driving style. The V8 isn't going to get you across 3 lanes of traffic any quicker than the Inline-6 in the 450 - it's a large, heavy vehicle and in those situations you're also going to be getting instantaneous torque from the ISG regardless of powertrain. It's about a .2 second difference 0-20.

Mercedes have always had a bit of a lazy throttle tip in compared to their competition in my experience.

mikapen

Now the engine response is dictated by throttle velocity, as well as position.

In other words, a very quick stab of the gas pedal overrides a Comfort setting and the car thinks you are asking for Sport+, downshifting and holding the lower gear, waiting for your next input.

It breaks traction on all four winter tires if I try to jump into a gap in traffic. It also runs wide. Oops!

It ain't lazy no more....
(Summer tires stick just fine. My 53.)

Splaktar

I don't know if 50% of the throttle is accurate or not. I haven't seen a display of throttle %, only brake %. The tech that did the test drive described it as "flooring it," but that's also not accurate at all, as I don't get near the floor or 100%. It could be as little as 10-15% of the throttle, but it's not 1-5%.

In the cases I'm describing, I can reproduce this by turning right into a single lane. When it pauses 1-2s, it causes me to miss the window there. I'm not necessarily looking to go "fast", but instead get moving promptly.

Splaktar

Now, that's helpful to know. I'll have to play around with that some once I get it back from service. I didn't know that this could override the Comfort setting, but that lines up with what I've experienced. I'm trying to better understand this because I'd like to improve both my Comfort and Sport driving experience.

I'm in Florida, so I only have summer tires, and the traction so far has been great. I've not had any kind of slip or peel-out yet.

wildta

You could also customize the Individual setting.

Splaktar

I'm for sure going to explore this once I get it back from service. Hopefully, that will be soon. It's going on day five now.

jkaetz

I did give this a try on our '21. I was never able to make it a smooth acceleration. Still felt the delay and then got a big burst of acceleration. Didn't have the vehicle status screen up to know how much throttle % I was commanding. Might check that the next time I wrangle it away from the wife.

Splaktar

OK, I got my GLS back today. With the Throttle display open, I saw that I use around 30-35% throttle when doing this. In the loaner GLE, I had to give it to closer to 35-45%. The GLS is far smoother and quicker. But the GLE gives you more feedback (front end raises up a lot, not a stable ride).

I also tested the throttle velocity some more. When I push it fast is when I see a delay and then a surge in (too late in some cases) power.

I tested some Comfort driving and kept throttle velocity low. Acceleration was very smooth. Now that I know that fast presses on the throttle drop you out of Comfort, I can better avoid that in order to keep the ride smooth.

I will try some Individual settings soon. Though, with the GLE, Sport mode is a huge change in performance, while in the GLS it's hard to notice major changes between Comfort and Sport.