Any ideas if ECO is worth using? I haven't really noticed any difference in mpg.

 

There is a growing notion among people who post on car sites, such as this one and others, that eco start-stop does nothing to improve real world fuel economy.

 

Not necessarily the start/stop but switching to ECO mode.

 

I don’t it was about better fuel efficiency, but rather about pollution in slow , high density traffic with thousands of cars idling in city traffic.

 

The start/stop feature is activated in both ECO and Comfort modes. I believe that ECO is meant to increase MPG but I haven't really noticed any difference.

 

There are a lot of variables to the answer to this question... For starters, it depends on the car, how annoying it is and also your daily commute, whether you spend tons of time sitting in traffic. On my wife's Tiguan, I've programmed it to be always off because its a terrible implementation, its rough and you notice an obvious jerk every time it engages. On my GLE450, because of the EQ Boost electric hybrid setup, it's virtually invisible and works seamlessly. There are other factors that have been debated regarding the wear and tear on the engine and components but again with the setup in the 450, its not your typical starter motor so that argument is somewhat irrelevant. I have been getting 26-27 MPG lately so it seems to be working well.

Another really cool feature of the ECO mode is the coasting ability. I've coasted for several minutes on the odd occasion and I can see my fuel economy numbers climb. It also uses the radar system to detect traffic ahead and engages the motor which then uses compression to slow you down. It's truly a clever system !

 

I agree with all of your points. I have the 450 and I feel the engineering of this engine is far superior in tech advances. It performs so well in so many ways and quite powerful.

 

The feature that’s different in Eco is the way the 450 engine is uncoupled from the drive train and shuts off going down grades or coasting while recharging the battery. That’s the way I remember the description. Never tried it but in the mountains it could make a difference in mpg.

 

Wonder what the effect is in the 350?

 

Probably just the eco start/stop. Might change the TCU to shift to a higher gear sooner.

 

Its call "Glide Mode"
On 350, the engine is decoupled from the transmission.
On 450, the engine is actually turn off when the condition met.

It is only active when engine is on ECO mode, and you can tell it is active when the gear indicator has a green 'D'

 

I don't recall seeing the charging side illuminated on my little EQ Boost gauge while coasting with the RPMs at 0. I'm pretty sure it only charges the battery while coasting with the drivetrain engaged and you aren't accelerating. The RPMs are low but not 0.

 

Here’s what Mercedes says about EQ Boost-Eco assist:

ECO Assist takes the following traffic situations and information into account in its driving recommendations and efficiency strategy:

• Route profile (bends, junctions, roundabouts)
• Speed limits
• Distance from vehicles ahead.

ECO Assist continuously generates coasting simulations in the background: depending on the charge level of the battery and the traffic situation, it computes whether the vehicle should ideally be allowed to coast freely ("sail") with the lowest possible driving resistance when releasing the accelerator, or whether it should be decelerated so that the battery can be efficiently charged (recuperation).

Within the limits of the system, ECO Assist regulates the impetus according to the situation as soon as the driver's foot is lifted off the accelerator. The driver is given a discreet prompt to do this by the appearance of a "release accelerator" symbol in the central display (or if installed, in the head-up display). At the same time a diagram gives the driver the reason for the recommendation (e.g. "Junction ahead" or "Gradient ahead").

To increase the driver's motivation to follow the recommendations of ECO Assist, the on-board computer records how many kilometres/for how much time during a journey the car is driven with the engine switched off, and shows this in the central display. Rewards not only materialise in the shape of reduced fuel consumption, but also of increased (fully electric) range.

This is for the S class-the display on the 450 only shoes the foot off accelerator if I remember correctly.

 

Thanks for the thorough explanation. Anyone have any ideas as how this operates in the GLE 350?

 

The stop/start function is at best an annoyance and eventually an expensive repair to replace the starter. I can't tell any difference between Eco mode and Comfort. Remember we're dealing with government bureaucrats who aren't that bright. These green technologies are developed to satisfy a feel good agenda rather than something practical.

 

Tried and tested and found to have a saving , trouble is that's the same lab treadmill that gives us the BS mpg figures too .

Real world no gain , switch it off , disable , program , your chain tensioner , engine mounts , starter motor , alternator , battery and ring gear will thank you for it .

 

I find the feature to be very annoying at times ... roll up to my garage door, press the opener, car has shut itself off for a few seconds etc. etc. etc. I can't believe it does anything significant for fuel economy but it certainly must add wear and tear to various components.

Worst of all, I was always taught with turbocharged cars NEVER to turn them off immediately after coming to rest unless they'd had a minute or so at idle (this is especially true if you've been driving hard) -- that's just enough time for the red hot bearings to cool down a bit thus prolonging the life of the turbocharger. Eco start/stop completely overlooks this element of "turbo care" -- okay, with modern bearing materials and synthetic oils etc. it's probably not as critical as it once was, nevertheless, it can't be doing any good.

I ALWAYS TURN OFF THIS DAMN ANNOYING FEATURE AND IF I COULD PERMANENTLY DEFEAT IT I WOULD.

 

I think you’re confusing the auto start/stop with the ECO mode. Start/stop is active both in the ECO mode and the COMFORT mode. My question is if anyone has noticed better MPG in the ECO mode?

 

I got almost 30 mpg for 200 miles in my 450 descending from Crater Lake to the coast (-6,000 ft.) using ECO mode. But, typically I don't bother with it.

 

Good point about letting the oil circulate to cool the turbo, and to prevent coking of the oil that would otherwise be left to bake with an immediate shutdown of the engine.
HOWEVER most manufacturers of turbo cars fixed that deficiency in the 80's, when they added electric-driven pumps (water and/or oil) that cools the turbos after the engine stops. So it's not an issue any more.

 

I wasn't really confusing anything with anything, but you're quite correct, you were specifically asking about ECO mode, which is not what I ranted on about.

 

That's good to know ... I wasn't aware of that ... is this 100% the case for our cars and for other modern era turbo vehicles?

 

You know, I should have said "I think" it's not an issue any more. I haven't kept up with all the turbo offerings for several years now, but it's "best practices" if you want to offer a turbocharged auto.
What I don't know, is if most manufacturers enable their thermo-sensors to re-start a cooling cycle should the turbo housing reheat from a heat soak, until the threat has passed completely.
And I assume (!) that what I heard from our Bluetec, for maybe 15 minutes after shutdown, was the coolant pump restarting from time to time to re-cool the turbo. I haven't noticed it with the 450, but I was still in break-in mode.

 

I've been using ECO mode exclusively for the past few days and I've consistently seen a 2-3 MPG improvement from comfort mode. I've been getting 26 - 26.5 MPG on my daily commute which is a mix of city and highway driving. That's very similar to what I was getting with my previous ML350 diesel. Pretty impressive !!!

 

I consistently used ECO mode in my 2018 GLC and now in the 2021 GLE350. I push it to Sport to merge onto short NJ hwy entrances. The GLC had a Sport+ which gave better shift points and more zip for merges. Never programmed Individual mode.