MLRLINCOLN

After driving new 2014 E350 Sport 4-Matic for four weeks now, I seem to turn off the Stop/Start feature more often than not.
I don't like being in traffic with my engine not running, doesn't feel right.
I can't believe I'am saving much gas since I don't drive much in traffic.
I've owned 8 new MB's in the last 24 years and I wouldn't be buying MB's if I were trying to save on gas.
What does anyone else think about this feature?

mleskovar

I like it in theory but have never experienced it. Makes sense...why pay for gas and produce emissions when you don't have to? From what I've read it's seamless as well......is it? What I don't get is you like the engine vibration at idle? Is there any downside to ECO other than something else to maybe require maintenance and the initial cost?

GregTR

The starter motor will take a beating and there is no A/C running while the engine is off which is probably a dealbreaker in the summer heat of the south.

I drive my dad's Touareg with the Eco start/stop feature and it didn't bother me until it was blowing hot air in the city. That was the point when I turned it off.

mleskovar

Are you sure it uses the starter motor? Or does it use a hybrid starter/generator flywheel like some other manufacturers?

I don't see this as a problem as the condenser takes longer than a few minutes to warm up and the AC fans keep running. I'm sure they accounted for this in their plans.

SolidGranite

Personally, I like it. In fact, I get pissed when it doesn't shut the engine down in traffic or at a light. It's kinda erie though when you're sitting at a light with no engine on. Nobody buys a Benz to save gas but then again if they make it more efficient is anyone gonna reject them and demand the gas guzzler? No chance.

Diesel Benz

Right, it does not use the starter motor. Funny how people know how bad these new features are but don't know how they actually work.

^^^^ could have been my words.

BenzV12

I have not found anything remarkable in regards to fuel eco with ECO button turned on vs turned off , it's all down to driving habits rather than a magic little rectangular button .I like it though .
A/C keeps blowing cold air but lowers fan speed and you have a second battery to feed the system

GregTR

"How the ECO start/stop system works in detail: as a general principle, the engine is switched off every time the vehicle comes to a standstill (auto-stop function. Restarting the engine (auto-starting function) takes place almost imperceptibly; and moving off without any noticeable time lag compared to a stationary vehicle with its engine running. This rapid action is attributable to two special features: a crankshaft Hall sensor which is able to identify the rotational direction of the crankshaft enables the engine control unit to identify the cylinder in which the piston is ideally positioned for starting. The fuel is injected into this cylinder first, thereby speeding up the starting process. An additional electric transmission oil pump supplies the clutches of the automatic transmission with oil pressure prior to starting, so as to enable a swift resumption of the journey after direct starting of the combustion engine via the ECO start/stop function. The starter motor (starter) has also undergone thorough modification: it is now designed to cope with eight times as many starting procedures, ensuring that it will last a car's lifetime in continuous urban driving involving frequent auto-starting. In addition, the on-board electrical system is supported by a second battery."

Sounds like a starter motor to me... It copes with 8x as many starts as a regular one. So if on average it gets used more than 8x on your daily journey it will wear out prematurely.

As for the A/C, I spoke of experience. The car starts to feel humid and warm after a short while. At least the Touareg does. And it wasn't even in Texas, it was in August in Europe.

MLRLINCOLN

Thanks for the info "GregTR" on how the ECO Start/Stop works.
I don't know how it works with the A/C running either, haven't been in traffic that long.

GregTR

The system actually should monitor A/C demand and disable auto off based on that.

"But the start/stop function can think beyond that: it is also able to start the engine automatically as an intelligent comfort and safety function. The engine control unit starts the engine automatically, without any intervention on the part of the driver, when one of the following conditions is met:

• A vehicle-related precondition for the auto-stop function, such as the conditions pertaining to air conditioning, the on-board electrical system, the brake system, the chassis and other vehicle-related influences, is no longer met.
• The driver releases his seat belt or opens the driver's door. Automatic starting takes place in order to prompt the driver to actively switch off the engine by turning the ignition key to position 0, prior to leaving the vehicle. This ensures that the ECO start/stop system is safely deactivated when the vehicle is parked."

mleskovar

Do you do a lot of city driving? Since emissions are closely related to gas consumption that wouldn't change much either in your case. I wonder what the ideal situation for ECO activation is? I'm guessing rush hour city with lots of pedestrian traffic to slow the flow. The claim is 3 - 5% gas savings and if you do the math on a large scale that's a lot of gas and emissions savings.

GregTR

It has to be stop and go traffic. Steady slow moving traffic does nothing. It also has to be extended periods of stops for the system to make sense. A E350 probably uses about 0.3 gallons per hour for idling so it's the equivalent of about a mile driven for every 10 minutes of sitting in traffic. A typical red light is probably around 60-80 seconds in length so you need to stop the engine 8-10 times for every gallon of fuel to better your consumption by 1 mpg which would be about 4% more efficient. So if your average commute involves about 10 miles and you have 4-5 red lights where the car stops your engine then you will see a 4% or so improvement in your fuel consumption. Interestingly it is also less than the 8x more reliable starter motor so it sounds pretty legit to use it.

My commute is 13 miles, mostly highway with 3 traffic lights. If I have to stop at every one of them I would see a saving of 2-3% in fuel consumption by using the system. But I will most likely hit some of those lights green on some days so it's more like a 1-2% saving for me. As always, your mileage may vary....

PGT

it's great for normal driving. when we get into stop/go, I turn it off. I've got the same thing on our BMW and its 10x more intrusive whereas its barely noticeable on the Merc....I chalk that up to twice the cylinder count and less motor vibration (i.e. more balanced).

PeterUbers

call me paranoid, but I turn ECO off when I'm taking a left turn against traffic .. something deep inside me says - the engine should be running right before I'm about to make this turn... I wish the ECO engineers could sense somehow that I'm taking a turn against traffic and disable ECO during these periods of time. Also I don't like it during incline driving.. hate that rollback briefly while it starts up... like driving a manual

oh, and 8x a trip--?? The engine starts/stops at least 20-30 times some local trips I make... I have the good sense to turn it off when it's just a nonsense situation to keep it on -- stop and go traffic, etc. I'm glad I have an extended warranty with this ECO... I wonder if the cost of a starter replacement or other parts therein would offset any fuel savings over the course of 50k miles if your starter were to go out after the b2b warranty...

edspider

I have had keyless Go functionality for years. And about once a year, I'm in a hurry and leave the car running. Hours later, I come out to find it running. Perhaps the Stop/Go feature will at least turn the engine off until the battery is compromised.

I do pay attention to gas mileage when I spend 60K+ on a car. It is a factor when I compare cars. I wanted the E250 but in Illinois only B20 is readily available and that voids the warranty, so I got the E350.

I would probably turn off the ECO feature downtown or stop and go traffic, but for suburbs with their long red lights, I'm game.

Jeffy

Anyone know a way to have the start up default to be ECO off instead of on? Or a way to just permanently disable it?

tjg0024

I like the feature since I do like the idea of being a little "green". It does in fact get hot when you are stopped with the engine shut off, the air does not get cold when you are on an ECO stop. Once you get going, you feel the cold air pretty quickly...

Karl901

If you get your car tuned, you can have it disabled.

Another thing they have figured out in Germany on how to save fuel. Yield signs instead of stop signs. There is very few stop signs. Coming to a full stop when it is safe to just yield saves a massive amount of fuel.
No, I am not going talk about fuel saving by using round abouts too.

BenzV12

Mostly city and highway with 8 lights ,24 kilometers one way . I believe in highly congested city traffic ECO should be saving some gas but in my case there are other factors that are involved in fuel consumption .

I am doing same thing as you,I am turning it off when coming close to making U turns , I want my engine to run before making turns just in case and I also switch it off or unfasten seat belt when parking the vehicle because I notice the car stops during park maneuvers and it's annoying to me

PeterUbers

I forgot I also shut it up when parking in the garage... can't stand it shutting off and on as I negotiate the 360 view monitor to get the car just right, also I do not like how it'll be on eco-off, and i'm ready to turn the car off so I hit the park button and then the start/stop button sequentially and everything is silent -- just is unsatisfying .. guess it'll take some getting used to. I also think that if the 360 view camera is active, it should keep ECO off, understanding that I'm negotiating a parking maneuver, so keep the engine running.

hopefully software upgrades for future E class owners

Arrie

Where did this technical writing come from? It is missing some info.

For the control system to know which cylinder is at firing position the crank shaft sensor alone is not enough. Information from the cam shaft position sensor also is needed.

Arrie

I was trying with my A/C one day on a highway how much it affects the fuel consumption. It is amazing 10 - 15% higher MPG with A/C off.

What I also noticed the vents kept blowing cool air for several minutes, at least four minutes, while the compressor was off.

GregTR

Straight from the horse's mouth: http://media.daimler.com/dcmedia/0-9...0-0-0-0-0.html

The discussion was more in reference to whether a starter motor is utilized or not (it is), not what other smarts and sensors are needed for a system. But I'm glad you pointed out that the information was partial in that reference, it makes a whole lot of difference in the discussion....

PeterUbers

how many years ago did the E start using ECO?

ljoeurban

Just curious, how much do the dealers charge ($US) to replace a starter on a
E350?