What do you know about Auto Start/Stop

WallieX5 · 12-30-2011, 12:18 PM

I do have it on my 535 and I thought I knew when it auto stops but lately, it has defied my logic.

I think that it won’t shut off when the engine is very cold.
It won’t shut off after a recent shut off if you only moved a few feet.
At times it just doesn’t shut off even when the engine is warm and I come to a stop.
The only thing that I know for certain is that it won’t shut off again after coming to a stop and you slightly let off the brake after it shuts off the first time.

How does it really work?

E30M3Driver · 12-30-2011, 01:42 PM

Quote:

Originally Posted by WallieX5

I do have it on my 535 and I thought I knew when it auto stops but lately, it has defied my logic.

I think that it won’t shut off when the engine is very cold.
It won’t shut off after a recent shut off if you only moved a few feet.
At times it just doesn’t shut off even when the engine is warm and I come to a stop.
The only thing that I know for certain is that it won’t shut off again after coming to a stop and you slightly let off the brake after it shuts off the first time.

How does it really work?

There are a whole bunch of logic scenarios - but here are a few in conjunction with your observations. System won't be active at all if:

- Ambient temp is <37.4 or >95 degrees F
- Perceives stop/go traffic
- Interior temperature is not at preset temp - warmed up or cooled down
- Low battery charge
- Max A/C
- Engine not at operating temperature

It won't shut off if you:

- Turn the steering wheel within 1 sec of coming to a stop
- Come to a stop with the steering wheel turned >90 degrees
- Come to a hard stop
- Operate the vehicle in Sport, Manual or Reverse

weissja · 12-31-2011, 05:07 PM

it will or may turn off in sport mode too.

mspeasl · 12-31-2011, 09:33 PM

When I test drove the new 2012 I found that if you used the "Auto Hold", the "Start/Stop" seemed to work much better.

gsmith999 · 01-01-2012, 12:40 AM

For me, the only way stop/start can work better is when it is inactive. Thanks to E30M3Driver for pointing out that Stop/Start is inactive when in sport or manual mode. I usually drive in DS mode anyway, but I was always pushing the button to turn off Stop/Start. Now I know I don't have to push this button anymore. Just kick the shifter over to DS mode and drive on....

///FCB · 01-01-2012, 04:29 AM

one question I always had about the start/stop option is - if it in anyway damages the engine and/or turbos in the long run? If you drove the car really hard at high revs (say on a highway), took the exit and came to a red traffic light and made the stop smoothly. Would the engine shut off? That would not provide time for the turbo's to cool down and the trapped oil will be burned. How is this avoided?

12-30-2011, 12:18 PM	#1
WallieX5 Private First Class 118 Rep 107 Posts Drives: Jahre IB G80 Join Date: Apr 2008 Location: MD iTrader: (0)	What do you know about Auto Start/Stop I do have it on my 535 and I thought I knew when it auto stops but lately, it has defied my logic. I think that it won’t shut off when the engine is very cold. It won’t shut off after a recent shut off if you only moved a few feet. At times it just doesn’t shut off even when the engine is warm and I come to a stop. The only thing that I know for certain is that it won’t shut off again after coming to a stop and you slightly let off the brake after it shuts off the first time. How does it really work?
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12-31-2011, 05:07 PM	#3
weissja Private First Class 13 Rep 158 Posts Drives: 2014 BMW 550i Join Date: Jun 2008 Location: Los Angeles iTrader: (0)	it will or may turn off in sport mode too.
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12-31-2011, 09:33 PM	#4
mspeasl Sixties Drag Racer 37 Rep 409 Posts Drives: 2011 Cashmere Silver 528i Join Date: Sep 2010 Location: Decatur, IL - USA iTrader: (0)	"Auto Hold" When I test drove the new 2012 I found that if you used the "Auto Hold", the "Start/Stop" seemed to work much better. __________________ Mspeasl - Central Illinois - USA : *My Garage:* 2011 - Cashmere Silver Metallic BMW, 528i (Delivered 17 January 2011) 2008 - Radiant Red Toyota, M6 'X-Runner' (Delivered 15 November 2007) 1957 - Chevrolet Bel Air 2dr Coupe' Drag Car (2nd Owner since 1964) 1947 - Chevrolet Sport Master Coupe' Street Rod (2nd Owner since 1974)
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01-01-2012, 12:40 AM	#5
gsmith999 New Member 2 Rep 23 Posts Drives: 2012 535i Join Date: Jul 2011 Location: California iTrader: (0) Garage List 2012 BMW 535i [0.00]	For me, the only way stop/start can work better is when it is inactive. Thanks to E30M3Driver for pointing out that Stop/Start is inactive when in sport or manual mode. I usually drive in DS mode anyway, but I was always pushing the button to turn off Stop/Start. Now I know I don't have to push this button anymore. Just kick the shifter over to DS mode and drive on.... __________________ 2012 535i Space Gray / Black Dakota / Anthracite Premium - Premium Sound - Tech - Cameras - Active Cruise Last edited by gsmith999; 01-01-2012 at 09:53 AM..
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01-01-2012, 04:29 AM	#6
///FCB First Lieutenant 26 Rep 330 Posts Drives: 2012 GTR Join Date: Sep 2009 Location: EU iTrader: (1)	one question I always had about the start/stop option is - if it in anyway damages the engine and/or turbos in the long run? If you drove the car really hard at high revs (say on a highway), took the exit and came to a red traffic light and made the stop smoothly. Would the engine shut off? That would not provide time for the turbo's to cool down and the trapped oil will be burned. How is this avoided? __________________ -2012 BMW 740D -2012 Datsun GT-R -2007 Mitsubishi Evo IX (sold) -2010 BMW M3 E92 (sold)
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