chuck007

My 2015 S550 has never shown signs of stopping and then starting when the car comes to a stop/rest. NEVER ! There has never been a warning message on the dash and the car drives beautifully and smoothly even from complete stops. However, JUST around town with speeds never over 40 and engine never getting over 200 degrees, I average 12 to 14 mpg. If the "stop/start" function was working, how much better would my mileage get ?? Thanks

MBS63AMG

I wouldn't be concerned. Sounds like you are not driving enough to keep the battery up to snuff to maintain the electrical demands at a stop. If you drove it 70 mph for over 30 minutes then drove around the city , the start/stop might kick in. I think the whole concept is a farce anyway as I can't see how this feature would increase mileage at all. Just my thoughts. Plus it's going to wear out your starter sooner. I keep my feature turned off all the time.

1bad540

Lol you think the mileage would go up after shutting off for 5 seconds and restarting?

obwielnls

It's not about the tiny amount of fuel saved by turning off at a light for 5 seconds to 2 minutes.. It's about all the cars on the planet doing that. That saves a lot of fuel.

Utopia Texas

I agree. Your car stopping for thirty seconds at a red light will not give you discernible better gas mileage. 10 million vehicles all over the planet 24 hours a day stopping for 30 second red lights will add up to great savings in fuel as a whole. It’s not about one vehicle.
We are the Benz, resistance is futile.....

MBNUT1

I try to drive my car to maximize the fuel mileage. You would be surprised how much sitting at a light will begin to erode your average mileage for a given trip. Now having said that I have averaged 25 mpg indicated on the dash for the nearly three years that I have owned it. Not sure that if I was averaging only 14 it would be as noticeable.

Wolfman

25 mpg in a S550? Sounds impossible to me unless all driving is on the highway. Ours was always city driving and I’d lucky to get 300 miles on a tank.

MBNUT1

No mine is an E3504matic and admittedly my driving habits combined with primarily driving on the highway yield exceptional mileage for that car given the epa highway mileage of 24. My only real point was that if you able to get decent mileage and you watch the average trip mileage gage you will see it knock off a couple of tenths of the average mileage for a 15 mile trip while you sit at a light, so the start stop feature does do something. Again if your mileage isn't all that great to begin with it probably wouldn't make that much difference.

tkelley.EClass

LMAO

1bad540

did you know It takes more gas to start the engine than to keep it running? I get in some circumstances it may save a hair, when i get a looaner c class it literally shuts off as Im moving 3 ft up at a stop light or waiting to turn.

docsout

Ozone loss is due to China and India still using dung as fuel for cooking and using 1940's diesel engines. The USA's 300M people don't amount to squat compared to their gazillions of people. Stop/start is marketing humbug. I can't imagine how much a new starter motor cost after constant use. Always turn my stop/start button to off.

Utopia Texas

The newer “Stop/Start” systems do not use the starter after intermittent stops. The fuel charge and compression on the next two cylinders ready to fire Is set by the computer. When you take your foot off the brake those cylinders fire and spin the engine to start the unit. This is how it was explained to me on my wife’s Cadillac.

MBNUT1

Super interesting.

chuck007

Do you know for sure that GM's system is what Mercedes is using in the S550.....this would make a huge difference in fuel savings and make a "start/stop" system begin to make some sense.

Utopia Texas

No, I have no idea what system Mercedes uses.....

ygmn

Then everyone should drive SMart cars to save way more fuel.