Rhschnauss

When the eco start/stop shuts down the engine, it stays off for 1 minute then restarts. Why would it not stay off until I accelerate? Also, I have noticed the system is somewhat clunky. It is very noticeable when it shuts down with a thud and when it restarts with a thud.

atlgapdo

I have checked with the dealer and the "thud" is considered normal for my 2015 S550! I even drove a new C-series loaner and it made the same sound.
It's a a total surprise to me to see a car of this caliber to make this kind of sound when in "eco" mode. I had been in rental Ford cars that were totally silent!
So I just choose to hit the button and shut if off before driving off....

MrAK

I have a short commute, so my start/stop almost never works. But, if I have a long highway drive the start/stop feature then works all the time when I'm in the city.

I think it depends on your battery charge, and I know when I'm stopping or coasting on the highway I have the battery charge indicator on. There is also I smoother transition of the stop/start function when the car is fully warmed up.

Utopia Texas

Nice Ride

Many many factors go into when and how long ECO will activate. Battery voltage, Engine Temperature, Accessory usage etc. In general on short trips in the cold weather, you may never see it activate, the same trip in warm weather, you may see it activate etc..

Rhschnauss

Utopia Texas

Mitch Alsup

My S600 start/stop works for 30-40 seconds in Texas summer heat and a bit over 1 minute in colder times of the year.
I think the A/C has some kind of accumulator and some kind of sensor, when the sensor goes click the engine goes back on.

MBS63AMG

I keep my car in Sport mode all the time as I don't like the feature. I feel it wears out the starter motor prematurely causing a visit to the shop for a starter replacement. But when I do happen to use it, I don't notice any clunking sounds. Mine works great. Let me add that I think the radar sensor (used for Distronic) senses when a car in front of you is pulling away, giving the system a heads up that you are about to need to accelerate.

hyperion667

That was always the first button I pressed, to turn off, or the S button. Still don't miss the S haha.

garygnu

i had a prius and i loved how the engine would shut - i felt like i was saving the money and maybe the planet. okay, money. i get annoyed when a car with start/stop doesn't stop at a light.
there are a ton of factors that are involved - including whether the catalytic converter is warmed up enough, battery level and demands, etc.
i think the rear defogger, lights, and ac would be the biggest reasons for it to fire back up.
i agree mine doesn't seem to stay off very long - i'd wager the way it is implemented it may be more marketing than real fuel economy. still, i like it in general, and if i know i want to accelerate i'll just gently touch the gas.
with the BMW, if you turned the wheel or took your foot off the gas, or shifted it would start instantly.
with the prius...well, nothing was instant on that car (my wife would call it the putt putt mobile - i frankly thought it was a $30k or so video game, just very weak engine power.
on the polar opposite, my 19 mpg (if i'm lucky) biturbo V8 is effortless power...

Bigdzx7

just reach your little hand over 12 inches and turn it off and turn it back on no big deal

BenzV12

I don't like that auto start / stop feature either . I have also experienced that I can see the engine can roar back to life even when I play with the A/C or unfastening the seatbelt ( the latter is just for testing lol )