[darrko]

1. What does it do exactly?
2. Is it a standard feature on all F10 variants?
3. I was under the impression it was only meant for manual transmissions. True/false?
4. So if you need it disabled, you need to do it once every trip?
5. Does it actually help save fuel? I thought every time the engine re-starts it would burn a tab bit more fuel.

[ghueser]

Originally Posted by darrko

1. What does it do exactly?
2. Is it a standard feature on all F10 variants?
3. I was under the impression it was only meant for manual transmissions. True/false?
4. So if you need it disabled, you need to do it once every trip?
5. Does it actually help save fuel? I thought every time the engine re-starts it would burn a tab bit more fuel.

1) It stops the engine at every stop. (under most conditions, there are exceptions such as on very hot days and needing the air conditioning to continue running.)
2) On all F10/F11's as of 2012. I think also on all other BMW's as well.
3) I know this is on Automatics, not sure about Manuals, but believe so.
4) You have to defeat the feature each and every time you start the car. There is a switch right underneath the start switch.
5) According to everything I have read, including sources other than BMW, it does end up saving fuel. Up to 10% for those that drive mainly in the city cycle, or are stuck in traffic. My guess is thar with the injection systems we havem including direct fuel injection, there really is no more waste of gas to restart the car.

[darrko]

Thank you very much for the information

Am I correct in understanding that most people don't really like this feature? I'm sure it would be quite annoying to have the engine shut down every now and then, and even more frustrating to not have complete control over this feature.

How does it work in real life though? You are in slow moving traffic, it comes to a halt and you brake. Presto! Your engine cuts off. You sit there for 15 sec and the traffic starts moving.....so what then? You floor the accelerator and the engine comes to life? Surely a few seconds are lost during crank and ignition, no? Or is it so seamless that you don't really feel the lapse of time?

[NoMods]

Stupid question, does it become a PITA if you like to accelerate quickly from a stop light? How many seconds do you need to be stopped before it kicks off/on?

[darrko]

It sure sounds like a PITA, kinda seems like it kills the edge of a probably great engine. They should at least allow the driver to configure the time interval the car stands still before the feature kicks in. What is with corps like BMW, Apple? They feel they know what the consumer needs better than the consumer. This option would be great for people who want it, but it should be user-controlled and exactly that: an option!

Ok, I don't even have my BMW yet and I'm already ranting. Sorry!

[ghueser]

Originally Posted by darrko

Thank you very much for the information

Am I correct in understanding that most people don't really like this feature? I'm sure it would be quite annoying to have the engine shut down every now and then, and even more frustrating to not have complete control over this feature.

How does it work in real life though? You are in slow moving traffic, it comes to a halt and you brake. Presto! Your engine cuts off. You sit there for 15 sec and the traffic starts moving.....so what then? You floor the accelerator and the engine comes to life? Surely a few seconds are lost during crank and ignition, no? Or is it so seamless that you don't really feel the lapse of time?

I think most agree that this is something they don't like. At least for now you have the luxury of defeating it, even though you have to do so each and every time you go somewhere. There will likely be an aftermarket fix to offering a better fix to the defeat in the future.

As far as how it actually works, others that actaully have Stop Start will have to tell you how it feels. From what I have heard, it is fairly quick to respond. The key word there is "fairly".

[islandnipper]

I've had my 2012 auto for a couple of months now (start/stop has only been available on autos since the new model year- it was on manuals for some time before (maybe from the intro of F10s?).

I thought I was not going to like start/stop (to put it mildly!) but actually I leave it going most trips and have come to appreciate the (presumed) economy advantage in jams etc. The thing is, (which has surprised me!) it doesn't get in the way, most of the time. I don't keep cars longer than 3 years, so I'm not worried about the extra wear and tear, which I guess has been taken into account anyway by BMW.

Engine stop varies according to engine warmth, steering position, road incline, power demands of air-con etc and battery condition (it checks that you have a well charged battery).

Start can be actioned in two ways, both quite fast! It depends upon the auto-hold parking brake setting (which, when "on", allows release of the brake pedal when the car is halted).

With auto-hold off, car stopped with foot on the brake, the engine re-starts as soon as you lift the brake pedal. It's fast enough to be fully ready as (or before) your foot hits the gas pedal.

With auto-hold on, the engine re-starts as you press the gas-pedal. Obviously there is a very slight delay as the engine starts during the initial pressure on the gas-pedal, but, particularly in traffic, its easily fast enough for normal traffic driving.

Clearly, when the fastest get-away is needed to be guaranteed (at a busy intersection etc) - or in frequently stopping/starting queues, it's best to over-ride the engine stop (easy enough)...

...but (IMHO) it is far less intrusive than you may expect and (again IMHO) easy to live with. I've quite surprised myself!

Hope that helps anyone that hasn't experienced it yet. People that don't like stop/start - please don't flame me... I'm merely stating what I've found over the last few weeks after not liking the idea at all before I had it!

[darrko]

Very well explained, makes things a lot clearer. Thank you for taking the time.

[Jon D]

Originally Posted by armoredsaint

Stupid question, does it become a PITA if you like to accelerate quickly from a stop light? How many seconds do you need to be stopped before it kicks off/on?

Perfectly valid question and, yes, it is a PITA if you want to move off quickly.
I've tried it in a 640i and a 320i and didn't like it in either car as I found there was a slight delay in taking your foot off the brake/pressing the accelerator and the engine restarting.
I disabled the system by pressing the switch, but that leaves you with an amber light, which might be annoying whilst driving at night.

[Crille]

The 550i and the 530i do not have the auto stop/start option
the 530i is not available in ever countries
I don’t know how it is in bmw but in some other cars with the auto stop/start function they do not use the starter motor to start the engine during auto stop/start, instead they use the generator as a starter motor.
You got a faster and smother start of the engine this way, the starter motor uses only when you press the start bottom, the generator has not the power to start a cold engine.

/Crille

[raleedy]

What I'm getting is that the ASS system is a problem in that it delays or slows jack-rabbit starts — something we all strive to perform as much as possible for maximum fuel consumption.

[AVIMAX]

I wonder if the slight delay is any worse than the "drive by wire delay" in my 535i without stop/start. Maybe this was the plan all along, get us used to cars that don't react right away now, so that when the start/stop becomes standard equipment, we won't notice the difference!!

[mspeasl]

Originally Posted by Crille

The 550i and the 530i do not have the auto stop/start option
the 530i is not available in ever countries
I don’t know how it is in bmw but in some other cars with the auto stop/start function they do not use the starter motor to start the engine during auto stop/start, instead they use the generator as a starter motor.
You got a faster and smother start of the engine this way, the starter motor uses only when you press the start bottom, the generator has not the power to start a cold engine.

/Crille

Currently I do not have the time to explain how it works. But a hint, it's in the computer and a little bit of the starter.

[BigKutta]

I have now experienced the start/stop for 6 days on my 2012 528i. In a nut shell, its not very smart. It can sometimes stop in parking lots while you are thinking of the parking space, while it may not stop at long traffic lights. Sometimes it will stop at traffic lights, and sometimes it will stop in stop-and-go traffic. If find it annoying because there is a quick "rumble" when it starts back up, so you are aware of this happening. The delay is hardly anything to be concerned about.

Islandnipper explained how it turns off and on, but I think there should be more intelligence built in. I personally like to turn it off, just wish that there was a way to turn it off permanently

[crmgr]

I had to drive a Toyota Prius while my car was in the body shop for a month last year. Hated the start/stop. Always felt like I stalled. I was glad to return it. Rather spring for the extra gas money.

[azray7]

I can appreciate the fuel savings, but how much unnessary wear and tear is this causing our ignition systems? That has to be much more expensive than the fuel savings.

[Jon D]

Originally Posted by azray7

I can appreciate the fuel savings, but how much unnessary wear and tear is this causing our ignition systems? That has to be much more expensive than the fuel savings.

It won't affect the ignition system, especially with a diesel, but over time, I would expect increased wear and tear on the starter motor.

[uda]

I find the Auto Start Stop function very good! Saves fuel and the environment. Why should you stand still and put out pollution to the air?
If you feel that you need to start very quickly, for example in a left turn on a heave traffic road, just turn the steering wheel an inch or two, and the engine starts. Or if you have stopped for red light and want to start real quick, put the transmission to SPORT, and the engine starts.

[Joe-BMW]

I leave it on under normal driving, however I shut it off in bumper to bumper traffic. Sounds counter intuitive but the more it engages the more annoying it is. If I had my druthers, I would disable it permanently.

[BigKutta]

Originally Posted by Joe-BMW

I leave it on under normal driving, however I shut it off in bumper to bumper traffic. Sounds counter intuitive but the more it engages the more annoying it is. If I had my druthers, I would disable it permanently.

Exactly what I do, and I also drive in DS mode most of the time and its turned off in that situation. Then once I hit an area with many long lights, I flip back to D. Love having the engine stopped at long lights, while everything is still on and seamless to me.

The feature has its issues (growing pains). Soon you will be able to customize the start stop for stop-and-go traffic (and parking lots) which is its biggest weakness right now. We are the test cases, it will only get better.

[Joe-BMW]

Originally Posted by BigKutta

Exactly what I do, and I also drive in DS mode most of the time and its turned off in that situation. Then once I hit an area with many long lights, I flip back to D. Love having the engine stopped at long lights, while everything is still on and seamless to me.

The feature has its issues (growing pains). Soon you will be able to customize the start stop for stop-and-go traffic (and parking lots) which is its biggest weakness right now. We are the test cases, it will only get better.

Are you sure about it being disabled in sport mode? I took delivery only a few months ago, I will have to check it out.

[AC_S5]

Originally Posted by darrko

3. I was under the impression it was only meant for manual transmissions. True/false?

For manual transmission vehicle, the start/stop work when you put the car in netural. Engine starts the moment you dip the clutch.