US 2011.5 Automatic Start/Stop

[flyingspaghetti]

I remember reading a question about what the user interface for AS/S looked like; after a quick forum search I don't think I've seen an answer, but apologies in advance if this post is a dupe. I'll try to keep this descriptive and minimize editorials about the usefulness of the feature.

On a US-spec "September" 2011 E92 M3, the disable switch looks like this:



After engine start, the default setting appears to be AS/S-disabled. Once enabled by pressing the switch, per the M3 supplementary manual, some conditions must be met for AS/S to stop the engine (M-DCT):

• Must drive faster than 5 mph
• Must brake to a stop
• Must be in D or S
• Driver's seat belt must be fastened, driver's door must be closed

There are some conditions which prevent the engine from being stopped:

• Steering wheel is being moved or is at max angle
• Outside temperature below 37ºF
• Climate control is trying to heat or cool the cabin
• Climate control is trying to remove window condensation
• Cold engine
• Discharged battery
• Open hood
• Car has been driven in reverse
• Steep hill
• Stop and go traffic
• Brake pedal released shortly after coming to a stop

When the engine stops, the cluster display looks like this:



Releasing the brake pedal triggers an engine restart, as do these conditions:

• Steering movement
• Entering N or R
• Climate control needs to cool the cabin
• Climate control needs to remove window condensation
• Battery is discharged

In a week of break-in driving, my experience was that AS/S (when enabled) activated infrequently. It was unclear to me how "stop and go traffic" was defined; the feature was most conspicuous in a congested stretch of Autostrada. The restarts are reasonably quick, but impossible to miss.

Maybe it will grow on me, but I found AS/S to be distracting. I'm happy the default is "off," and would be even happier if BMW could escape the habit of using a bright light to tell me that a feature is not in use.

[radiantm3]

Thanks for the details. I've read a bit about it elsewhere, but you've made it much more clear as to how it functions. Is the startup pretty much the same as if you were to start the car yourself? I guess I'm curious how it would look to the driver next to you at a light. Personally I'd think it would be weird to see a person manually stop and start his engine at every stop light so I'm just curious if that's how other people would see it without knowing the function of the car.

[TTG]

This feature is pretty common in cars in Europe. I've recently spent some time in Ireland and my rental car (2010 Passat) had this feature.....which I hated. I made a habit of disabling it the min I got into the car..... Pretty useless IMO.

[JCtx]

Originally Posted by flyingspaghetti

I would be even happier if BMW could escape the habit of using a bright light to tell me that a feature is not in use.

Yep, should be lighted when 'ON', not 'OFF', just like the other lights .

[swhat]

i like it. it's actually pretty cool hearing the engine startup every time you disengage the clutch. totally help keeps me awake in traffic.

[Finnegan]

Does anyone know exactly how much gas this is supposed to save?

Why not add something I really need, like a pulse ion-cannon or a rail-gun?

[mkoesel]

Originally Posted by flyingspaghetti

I remember reading a question about what the user interface for AS/S looked like; after a quick forum search I don't think I've seen an answer, but apologies in advance if this post is a dupe. I'll try to keep this descriptive and minimize editorials about the usefulness of the feature.

Thanks for posting all the details. As expected, the on/off button is the same one that has been used on the 3 series in Europe since 2007 (or earlier) and the same as on the M3 in Europe from March 2010.

It's interesting that the default is off. I think this will make most people very happy. One question though - are you saying you own or have driven a US spec 2011.5 M3? If so, I am curious if the default of off is different from European spec cars (M3s mainly, but other 3 series as well), or if they too default to off.

[saurabbhatia]

Wow nice feature just glad I missed it.. .. I was first sad that I didn't get that feature but after reading about it I would have probably just kept it off..
Would have loved a feature like only 4 cylinders running while the mode is active and have an option in the M-Mode to re-activate all the 8 cylinders.. or have the option on off..

Now that is a feature I don't mind having...

[michaelw9]

Thanks for the details, again. It's nice to see the default is on. Do you know if it remembers your choice? That is, if you decide you like it, do you have to keep turning that option on every time you go for a drive? Or, is it always off unless enabled?

[VonSwoopington]

The button was always off by defualt (meaning the light was on) during my ED experience. The feature is disabled until you press the button to turn it on (the light is off). It will remember your setting upon stopping or starting the car.

Thanks for the detailed information though!

Also, what is the button to the left? Sunroof?

[radiantm3]

Originally Posted by VonSwoopington

Also, what is the button to the left? Sunroof?

Rear Sunshade.

[michaelw9]

I guess if I end up hating it, it will be pretty easy to open the console up and find a way to kill the light.

[1MORELAP]

Nice update. I will try to get used to it enough to measure the difference in mileage with it on and off. Who knows, 1 MPG extra maybe worth it.

[flyingspaghetti]

Originally Posted by radiantm3

Is the startup pretty much the same as if you were to start the car yourself? I guess I'm curious how it would look to the driver next to you at a light.

Yes, it's just like starting an already-warm engine. It's reasonably smooth (considering the size of the thing), but you can certainly feel it inside the cabin and would be able to hear it if you were standing nearby. I tend to think the driver next to you wouldn't see anything unusual, though.

[satinghostrider]

If you have a loud exhaust and it keep dying off like that at the lights, people who don't know about this sure is not going to buy one. Hahaha...

It is definitely much more irritating if you have a loud ass exhaust.