cptobvious64

Hey y'all I'm looking for more information of what ECO mode does to the engine and cars performance to save fuel. I've found this tid bit from mbworld


[I]ECO drive mode is for the w205 owners who value low fuel consumption. Through a start-stop feature, this mode shuts off the engine when it's not needed (i.e., at traffic lights) to save fuel and reduce emissions. The vehicle will also enter a "gliding" mode. Each time you ease off the accelerator, the vehicle will use its own kinetic energy to "glide" along the road and disengage the engine, making for a smoother as well as more efficient ride. Upon engine restart (or cold start), the crankshaft sensor will select and ignite the cylinder with least resistance, which will further reduce fuel consumption[/I]

But I still have a few questions left unanswered. So does eco mode shut down any cylinders ? I should mention I'm driving a c400 but I'm curious about how it works on 300 and 450 as well. There is no mention of throttle response but obviously thats a huge difference, how does that work?

This glide mode feature I only just noticed it when I seen it written. Is braking affected in anyway on ECO mode? Less agressive?

Did anyone run any experiments on ECO vs Sport +? How much mpg on a full tank of gas with either eco or sport+ on 24/7 respectively?

Any input is appreciated!

DapperStyle

ECO Does not shut down any cylinders. It does 2 things: Shuts the engine off when stopped and makes the transmission shift as early as possible to save fuel. In Sport and Sport+ the car holds the gears longer allowing you to rev up to 5000+ before shifting giving you the most power out of the powerband. Start and Stop alone nets about 1 MPG on average depending on how often/how long you are stopped and obviously if you are already coasting in 7th gear at 35 MPH you are saving fuel (ECO mode) vs being in 2nd gear at 35 MPH (Sport+).

Braking is not affected but engine braking is reduced in ECO which could give you the perception that you have to brake more or harder.

Gliding mode is tricky, it is available in some markets but not in the US and other markets. It uses sophisticated decoupling to essentially put the car sort of in a pseudo-Neutral when coasting. Reason I say pseudo is because on modern direct injection engines when coasting in Drive the injectors shut off to save fuel, if you were to manually shift the car into neutral while coasting down a hill it will not do that and you are instead putting strain on the drive train.

cptobvious64

Cheers thank you Dapper this is great information. So now I have to find out if my car has the glide feature? It's from Canada but that's just US's younger brother so I suppose it doesn't.

And so you're saying most of the magic happens in electronically changing the gearing.

cenzo86

I'm typically driving my c450 in ECO mode. My daily drive is a lot if stop lights. I turn off the start stop, and like the pedal travel in ECO mode better than in sport plus is those conditions. You can just roll deeper into the pedal while using the low end torque rather than it downshifting. Plus, I put on the immediate gratification meter because I seek constant reinforcement. The start stop actually works very quickly. I'm just too impatient to wait for it.

DapperStyle

No problem, in this thread there is a discussion and youtube video of the function: https://mbworld.org/forums/c-class-w...tion-gone.html

Basically you watch the RPMs drop once he lets off the accelerator. Not sure if CA gets it or not.

Yeah which is why the car feels like it has less power- it's trying to shift extremely early into the higher coasting gears to save fuel. So the magic is really early shifting, decrease any engine braking, and turns the engine off when coming to a complete stop.

DapperStyle

Also a way to show how being in different gears affects MPG do this:

Set you cluster to show the instant MPG gauge, drive along in Comfort and allow the transmission to shift itself until you get to 6th gear at least (let's say 40 MPH), hold the left paddle at this time to drop the transmission into the lowest possible gear (it does it automatically when you hold that paddle for a second or so) the transmission should drop to 2nd or 3rd gear and watch the instant MPG gauge drop as your RPM gauge shoots up.

topsider

What I notice in eco mode is that the car definitely doesn't enter any "sailing" mode, even coasting down steep hills you can still feel the engine braking - maybe thats a europe only feature. Also, the only real difference is that the throttle is a lot less sensitive, the AC enters eco mode, and it doesnt really shift that early. no matter what driving mode im in my car always waits till about 2.5k+ to shift into second. I play around with the modes all the time and see no real difference in MPG in City driving, sometimes it is worse in eco mode because it takes longer to accelerate with the neutered throttle response. Better to just get up to speed in comfort mode IMO

gfmohn

Georgia overdrive in a Mercedes! Maybe when your Mercedes is in Georgia overdrive, your radio receives only trucker songs, such as:

I got me ten forward gears and a Georgia Overdrive
I'm taking little white pills and my eyes are opened wide
I just passed a Jimmy and a White
I been passing everything in sight
Six days on the road and I'm gonna make it home tonight.

--"Six Days On The Road," Earl Green and Carl Montgomery

(Georgia overdrive is trucker slang for placing your truck's transmission in neutral at the top of a large hill. You are totally out of control! You are betting your life and the lives of anyone in your way! So it is totally illegal, and probably this "pseudo-neutral" is too, at least in the U.S.)

topsider

right, i know the car is not supposed to go into neutral or feel like it, however it is supposed to temporarily disconnect the engine from the transmission for greater efficiency. There is definitely no sign of that in my car.

Steve71

I have a Canadian C300 and it doesn't seem to coast downhill. I've watched the rpms stay up while coasting downhill at multiple speeds. So I suspect it has the same logic as US cars.

GerritKw

I am from Europe and have a C350e.
This has some extra Eco features.
1. When gliding/coasting, the engine shuts down fully and the transmission is fully decoupled
2. When the distance between you and the car in front of you decreases, you get 2 pulses in the accelerator pedal to indicate to you to release the accelerator
3. It automatically starts recuperating/braking if you get closer to the car in front of you to prevent more excessive braking (without recuperation) later on

I am wondering if the C300 Hybrid has this behavior also.

mister__p

Correct - I live in Asia.

Yup, thats's what I have. During gliding, it actually say "Glide Mode" and you can see the RPM drop to ~700.

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The techy part of me wants to understand what is happening but I cannot explain the gliding mode randonmess. There are obviously many more parameters being considered under-the-hood, not only vehicles ahead, speed & inclination. Nb. I dont have any GPS features in my car so it can't be that either.

As for the Eco Engine Stop/Start button - that definitely does not toggle on/off the gliding like many other have said it does in their cars so there may be a software/sensor glitch in mine?. Will check with MB at my first service but software seems unlikely as my car is a recent build and the sailing aka gliding mode has been around since at least 2015.

Apologies to the US folks here for causing some head-scratching

ggoncruz

I have read that the ECO Start / Stop feature can be bad for the engine, does anyone here know for a fact that this is a true statement? It is hard to believe that MB is building a feature in a car knowing that itīs bad for the car when thatīs a pretty common feature in all the brands right know. Thanks!

gfmohn

You answered your own question.

Dukk

Not that I have had my car that long but I have driven in ECO exactly one time. I did notice the display flash Glide Mode a couple of times while driving and was curious WTF that was all about. I'm in Canada btw.

Ultimately, I thought the performance was lacking compared to Comfort mode and just leave it in that 99% of the time. I am fortunate that I don't pay for my gas anyway.

jlr82

I love ECO mode in the city. Early and much more comfortable gear shifts are really nice when you're going stop sign to stop sign or light to light. It also downshifts at lower RPMs for a more smooth roll to a stop as well. Who needs performance when you're going to get up to max 35-40mpg anyway?