Everything You Ever Wanted to Know About the Start/Stop Feature on your F30 3 series

tim330i · Mar 9, 2012

One of the most interesting, possibly obtrusive and certainly confusing new "EfficientDynamics" features added to the 2012 F30 3 series is the automatic stop start system. Stop/start is standard equipment on all new F30 3 series and is designed to save fuel while the car would otherwise be idling. The stop start functions differently depending on the transmission choice.

Automatic Transmission
Stop/Start will shut off the engine whenever the car is brought to a stop, so long as the transmission remains in D and the brake pedal is pressed to keep the car from moving. The engine is shut off after approximately one second and the tachometer needle will point to the "ready" position. As soon as the brake is released the engine starts and you continue on as normal. The driver can also select P while the engine is off and release the brake pedal, by then selecting D again the car will automatically start.

Manual Transmission
Stop/Start will shut of the engine whenever the car is brought to a stop, the car is in neutral and the clutch pedal is released. The engine is shut off after approximately one second and the tachometer needle will point to the "ready" position. The car is automatically restarted when the clutch pedal is depressed and you continue on as normal.

BMW F30 stop start tachometer in 'ready' state

BMW F30 stop start tachometer in 'ready' state

Interesting Quirks/Features

The engine can be restarted by the driver in anticipation of driving off by: briefly applying additional pressure to the brake pedal or by releasing the break pedal slightly. Both will cause the engine to start.
If "Automatic Hold" is activated the car will hold itself once the car has come to a stop and the engine has been switched off freeing the driver from needing to hold the brake pedal. Applying the brakes will cause the engine to start automatically.
It is possible to prevent engine shut down once stopped in order to be able to drive off quickly. Within one second of stopping apply additional force to the brake pedal and then release the additional pressure and continue holding the brake pedal with "normal" force. Whatever that means.

Why isn't my Stop/Start working?
There are numerous vehicle parameters that are monitored as a part of the stop/start function to ensure the driving experience is not impacted. As many of the factors are not possible to monitor it may appear that the feature is not working.

Reasons why the stop/start may not shut down the engine include:

The car is coasting (manual transmission)
Brake vacuum reading is too low (manual transmission)
Insufficient brake pedal pressure is being applied to hold the vehicle stationary (automatic transmission)
Stopping on a hill/downhill with a 12% or greater gradient
If the steering angle is more then 6 degrees
If the steering wheel is being moved after approximately one second of coming to a stop
The system has not yet be activated by going over a speed of 5mph for automatics, 3mph for manuals since the last engine switch off
If the gas pedal is being pressed (engine must be at idle speed only)
You're coming to a stop from reverse
The driver gets out of the car
If Hill Decent Control (HDC) is activated
If the engine is not up to temperature
If the carbon canister is being purged
if the grade of the fuel is too low for the engine
Transmission adaptation is active (automatic transmission)
The hydraulic pressure accumulator is not yet up to pressure (automatic transmission)
Stop-and-go traffic - system is only activated by driving over 5mph for automatics, 3mph for manuals
Batter charge is low
Outside temperature is colder then 37.4 F / 3 C
Outside temperature above 95 F / 35 C and the air conditioning system is on
Fogging of the windshield is detected by the IHKA system
Climate control system is on but passenger compartment has not yet reached desired temperature
ABS system was used when coming to a stop

Alternatively the car may automatically restart outside the standard restart procedure if:

The driver is moving the steering wheel
The driver presses the gas pedal
The transmission was shifted from D to P and subsequently back to D
The transmission is shifted to N or R
The battery charge runs low
Outside temperature rises above 95 F / 35 C and the air conditioning is on
Fogging of the windshield is detected by the IKHA system
Low evaporator temperature is detected

Disabling Automatic Stop/Start
The stop/start feature can be manually disable by pressing the button above the engine start button. BMW is now offering the ability for stop start to remember the last mode, meaning if stop/start is shut off and you completely shut down your car, it will remember the last mode and will not automatically re-enable stop/stop start. This can be coded by your dealer, read the service bulletin here -

http://www.bimmerfest.com/forums/showthread.php?t=636783

Impressions
The Bimmerfest Long Term Review Project 328i is mated with a 6 speed manual. The stop start function impressively does work with the manual transmission, however, I find it odd to sit at a light in neutral with the clutch out. When I was taught to drive manual I was told to always leave the car in gear in case you need to move suddenly. Therefore I tend to sit at lights with the clutch in, in first gear, so the stop start function never acts. When I do remember to use it I think it is the funniest thing to have it shut off the engine. I'll use the feature to entertain passenger and show off the technology of the F30. The rare cases where I'm at long lights it is nice but my daily commute doesn't have enough lights to make the gas savings worth much. It is disappointing that it doesn't work in stop-and-go traffic, that is where I would expect the majority of fuel savings would be seen by F30 3 series owners.

On an automatic where it can function without any change to ones driving habits I think it is a great way to save on gas. If someone with an automatic can comment on how it is that would be great.

stampchez · Mar 9, 2012

I have a manual and find that it is totally annoying in stop and go traffic. I haven't found the situation where it doesn't turn off. It just feels like turning off the engine and then turning it back on a second can't be any good for it.

ljgmdad · Mar 10, 2012

Yikes. I agree. Can this "feature" be disabled once and for all?

sr5959 · Mar 9, 2012

Great post Tim, especially for me as I have 328i Auto, and for a few days I was sure there was something wrong with the system as it wasn't activating. I believe that was caused by some cold temperatures in the first few days I had the car, as it is now working most of the time.

I find it really interesting in action, and I appreciate the silence and no vibration when the engine is stopped. The vibration as it restarts is a little bit off-putting, but more to passengers than driver I find. In hybrids this system works better because they move off from rest on battery then restart the engine while in motion which is a lot smoother.

Overall I definitely like this feature; just adds to all the other new technology in this car which makes it interesting! :thumbup:

pcbrew · Mar 9, 2012

What is: "Transmission adaptation is active (automatic transmission)" ?

I was taught not to sit at a light with the clutch in, due to additional wear on the throwout bearing. Not sure if that's still a concern in modern cars, but seems I wouldn't have to change any habits.

mohrgan · Mar 9, 2012

pcbrew said:
I was taught not to sit at a light with the clutch in, due to additional wear on the throwout bearing. Not sure if that's still a concern in modern cars, but seems I wouldn't have to change any habits.

Absolutely this is still a concern! Clutches haven't changed much.

I still have not driven an F30 but I think S/S would drive me nuts!!!

nofuture · Mar 9, 2012

I love this feature at the long and infrequent stop lights, rail road stops (when train is coming)

In a city driving with frequent stops and goes it gets annoying really fast. I think mellow/easy going drivers should not have problem with it.

Agressive drivers will hate it.

eclampsium · May 9, 2013

that's it. you nailed it perfectly!

Michael Schott · Mar 9, 2012

Thanks Tim. It sounds similar to my wife's Honda Insight hybrid. The stop/start feature is something you get used to after a while. Then it becomes second nature.

Mets335 · Mar 10, 2012

During my test drive I found it to produce a lot of vibration at start up - definitely noticeable. I would turn it off all the time. Not worth the 1 mpg it probably saves. It's a $40-$50k car and that start up vibration cheapens the experience.

justinnum1 · Mar 10, 2012

also pulling a paddle starts the engine

malc410326 · Mar 10, 2012

My personal preference is to shut off the Auto Start/Stop. I admit, I may just not be willing to adapt to a new technology that in the long run could save me money at the gas tank....I just can't seem to get comfortable with what I call the "Bimmer shimmy-shake" that my F30 does each time the battery turns off and on....I have to confess, the first time I experienced the Auto Start/Stop at the first stop light we encountered, my wife and I looked at each other in horror thinking that our car stalled. Then when it came back alive, we both breathed a sigh of relief. I admit, during our test drive, we had not experienced the Stop/Start feature, we were just aware of it as a standard feature and I thought to myself, "That's cool."But since we test drove on the highway in Sport mode (yes, sport mode made me fall in love with this Bimmer), we never had stopped at a stop light or anything of the sort! So my usual ritual is to make sure I push the Auto Start/Stop button after selecting the Sport Mode and I'm off into the countryside for a quick drive or set my mode back to Comfort Mode when I'm back in town (and proceed to make sure Auto Start/Stop is off). And then of course, I'm looking forward to a long road trip to try out the Eco Mode....

Maybe in the future, I'll give Auto Start/Stop a chance again....Time will tell if I'm able to evolve or not. :dunno: We should count ourselves lucky, since we have an option to turn this feature on and off. By the way, do the other hybrids (i.e. Prius, etc) do the 'shimmy-shake' that the Bimmer does?

jgrasty · Mar 10, 2012

You may find that you have to change your driving style if you allow auto start / stop to operate. The worst part is when you are turning left across traffic, as you have to allow 2-3 seconds for the car to start back up before you can turn. I usually just turn auto start/stop off.

m8o · Mar 10, 2012

tim330i said:
...however, I find it odd to sit at a light in neutral with the clutch out. When I was taught to drive manual I was told to always leave the car in gear in case you need to move suddenly. Therefore I tent to sit at lights with the clutch in, in first gear, so the stop start function never acts...

Really? [!]

Back in the early 80s, my pop used to yell @ me for doing that in our F150. And the clutch on the F150 did eventually fail from broken fingers on the pressure plate. The guys in the shop backed my father saying it was because I'd leave the clutch depressed for long periods of time. ... these days, I yell at my wife if I catch her doing it even for seconds.

So looks like autostop should be quite natural for me, cause neutral no clutch is the only way I [don't] roll.

silberma · Mar 10, 2012

OK, so this feature save 1 mpg in city driving. The saving may never be offset by the increased maintenance costs of premature starter wear. Only time will tell how the starters are holding up in this severe use. Also keep in mind that when you restart the car it uses electrical energy from the battery which needs to be recharged when the engine is restarted. On short stops there may be no savings at all.

Weaselboy · Mar 10, 2012

I was thinking the same thing on my test drive. It stopped probably four or five times for 10-20 seconds each time. After factoring in a recharge of the battery after each start, I really wonder how much fuel savings there is. I can see some savings in city traffic where you are at red lights often and a minute at a time.

It would be interesting to see some controlled tests of this with it on and off.

bcl0328 · Mar 10, 2012

silberma, I read somewhere that the auto stop/start uses its own starter.

jgrasty · Mar 10, 2012

There is only one starter in the car. RealOEM

Phillyd2 · Mar 10, 2012

After about a week in my 335 Auto I too find it annoying. Will give it more time to make sure I really hate it. If so, its on the list to be coded - it possible.

CE750Jockey · Mar 10, 2012

Whether you like it or not is a personal thing, I guess. What I hate is that you can't permanently turn it off. Give us the damn choice! Is that too much to ask?!

Michael Schott · Mar 10, 2012

Yes it's too much to ask of BMW. The car's CAFE numbers are based on stop/start being part of the normal operation of the car. If BMW allowed it to be defeated it would have to be tested for CAFE in that mode. Don't ever forget that is all about meeting CAFE requirements and will be normal on last cars in the next few years. Get used to it.

jmsent · Mar 10, 2012

I would expect that there could be a fairly easy hardware workaround to disable the auto start stop automatically when the car is started, assuming you're just closing a set of contacts on the disable switch. Might have warranty implications, though.

EdCT · Mar 10, 2012

I wonder how well this feature will hold up over time ... :dunno:

newBMWinLA · Mar 10, 2012

Stop/Start isn't new

I've had a Honda Civic Hybrid for 10 years with Auto Stop/Start, and i've never had any trouble with it. Oddly, I've test driven the F30 a couple of times (going to get mine ED in May!), and my civic's restart is much smoother than the 328's. For those of you who know hybrids, the Civic restarts directly on gas, it does not go to electric and then gas like some other hybrids, so that's not the answer. My guess is that it is probably because my civic's engine is tiny and weak and its entire construction is geared toward all of these little efficient dynamics.

Either way, you definitely get used to auto stop/start, and as the system matures, it does get into a better patter for stopping (i.e., mine stopped shutting off in stop-and-go traffic after initially shutting off at every opportunity.)

F30owner · Mar 11, 2012

newBMWinLA said:
I've had a Honda Civic Hybrid for 10 years with Auto Stop/Start, and i've never had any trouble with it. Oddly, I've test driven the F30 a couple of times (going to get mine ED in May!), and my civic's restart is much smoother than the 328's. For those of you who know hybrids, the Civic restarts directly on gas, it does not go to electric and then gas like some other hybrids, so that's not the answer. My guess is that it is probably because my civic's engine is tiny and weak and its entire construction is geared toward all of these little efficient dynamics.

Either way, you definitely get used to auto stop/start, and as the system matures, it does get into a better patter for stopping (i.e., mine stopped shutting off in stop-and-go traffic after initially shutting off at every opportunity.)

I agree about the engine size. I test drove both the 328 and 335 and paid attention to the start/stop. The 328 seemed a bit smoother than the 335. And I think the quite/smoothness was due to a small vs bigger engine.. possibly ...

Yobyot · Mar 11, 2012

I drove a 328i the other day -- when it was cold, I was shocked at how abrupt the restart was. Even after the engine warmed a little, the restart was annoying. Shutdown was smooth.

I suspect there's a software update in the 328i's future to smooth out that restart.

sr5959 · Mar 11, 2012

This function doesn't work on mine until the car is fully warmed up. Maybe some already have a s/w update???

Phillyd2 · Mar 12, 2012

LOL you guys are funny. Of course market forces work, even for the auto industry. I can't think of any auto safety product that was mandated by the .gov and then developed and installed into cars. Seat Belts, ABS, Airbags, etc. were first developed by the industry, introduced to the consumer and then copied by other car companies. It is true that most started out on more expensive cars before trickling down but the .gov only mandated them AFTER they were known and proven technology widely available to the consumer.

Even without mama .gov would anybody really buy a car these days without airbags and seat belts?

When the .gov does mandate before the consumer market place demands a product the end result is the Chevy Volt. Well done central planning.

I'm not again the.gov. Not even against sensible regulation. But anyone claiming we are today anywhere close to being sensible must be living on a different planet.

samualcc · Mar 12, 2012

Phillyd2 said:
LOL you guys are funny. Of course market forces work, even for the auto industry. I can't think of any auto safety product that was mandated by the .gov and then developed and installed into cars. Seat Belts, ABS, Airbags, etc. were first developed by the industry, introduced to the consumer and then copied by other car companies. It is true that most started out on more expensive cars before trickling down but the .gov only mandated them AFTER they were known and proven technology widely available to the consumer.

Even without mama .gov would anybody really buy a car these days without airbags and seat belts?

When the .gov does mandate before the consumer market place demands a product the end result is the Chevy Volt. Well done central planning.

I'm not again the.gov. Not even against sensible regulation. But anyone claiming we are today anywhere close to being sensible must be living on a different planet.

Quite frankly, there are people out there who drive without a seat belt on, drive drunk, drive without insurance, etc. Some people may pass on seat belts and airbags if given the chance to spend less on a car. This actually would prove that market forces do work in the auto industry, they just may not always be desirable.

There is clearly a balance to be struck between regulating common sense things, such as child seats for infants, and trying to prop up something like the Volt with huge tax credits. Though honestly, the number of Volts planned and actually built is so small when compared to overall car sales, I am not sure I would consider it government regulations gone crazy.

Now run flat tires on every car, that would be a good example of overreaching!

Phillyd2 · Mar 12, 2012

Well, its seems like you guys are not alone in accepting the fact that .gov knows better than the governed as evidenced by the state of affairs these days. Despite the will of our Founders and the general principles that served so well for so long. Once we accept that the State may mandated seat belts for our own good there is no intellectual argument against mandating run flat tires or anything else. Again, well done do gooders. :thumbup:

EdCT · Mar 12, 2012

You really believe the founding fathers didn't think they knew what was best for you?

Phillyd2 · Mar 13, 2012

Based on your posts you may be better off reading the European constitution. :rofl:

Michael Schott · Mar 13, 2012

Maybe instead of being insulting you should take your political views to the appropriate forum on this site. There is a Political Science forum under the Off Topic forum heading.

Phillyd2 · Mar 13, 2012

OK, thanks for explaining that its not political talk that's forbidden as Mike suggested but only those with differing views. Now that I understand I will sin no more.

Andrews335ic · Mar 14, 2012

At least the M3 start/stop defaults to off when you start the car!

Phillyd2 · Mar 14, 2012

As it should be.

rajens00 · Mar 15, 2012

It's been a fun 12 year ride with 4 BMW 3 Series but we're going to have to end our relationship since this auto start/stop can't be turned off, except manually each and every time you drive car. Sorry, it's unacceptable. It's a nice OPTION, but you shouldn't FORCE FEED you customers.

tim330i · Mar 15, 2012

Tell that to the NHTSA and your congress person, they're the reason you can't default it off.

Tim

ProRail · Mar 20, 2012

Wow. I knew that most BMW owners were totally self-centered but I never knew so many of them would declare it with such vehemence. Happy to say not all of us feel this way.

Everything You Ever Wanted to Know About the Start/Stop Feature on your F30 3 series

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