[Ilyam5]

So. No possibility to turn auto stop off anymore?
Not only do thy make us lag around more weight. Now its an inconvenience and a change to the way we drive
Start stop is the worst thing you can do for the engine longevity
Whats next? M3 will coast on track with engine shut off?

[Jostack]

Originally Posted by Ilyam5

So. No possibility to turn auto stop off anymore?
Not only do thy make us lag around more weight. Now its an inconvenience and a change to the way we drive
Start stop is the worst thing you can do for the engine longevity
Whats next? M3 will coast on track with engine shut off?

Doesn't auto stop disable in sport mode?

[Flamingi]

Originally Posted by Ilyam5

Now its an inconvenience and a change to the way we drive

How is start stop an inconvenience? How does it change the way you drive? Keep in mind, they use a crankshaft mounted integrated starter, so the engine is turned on instantly, no lag at all compared to the normal start stop systems of the last generation. There is no reason to keep the engine running if you are not using it anyway, so it does not change the way you drive. It is also no inconvenience, because the engine starts when the car in the front moves, as well as soon as you lift your foot from the brake. Since it instantly turns on back again, before you can even move your foot from the break to the accelerator, the engine is running already.

Originally Posted by Ilyam5

Start stop is the worst thing you can do for the engine longevity

No it isn't. The engine is warm, there is still an oil film left (technically you can run an electric oil pump even if the engine isn't running, idk if that is implemented in BMWs), The ISG turns the engine with 1k rpm, so there isn't any more load than in idle and no higher fuel consumption while starting the engine.

In summary I would say the only downside is the increased weight. It does offer more advantages though, mainly reduced fuel consumption (about 15%, that's quite a lot) and torque boost (significantly reduces turbo lag).

Edit: Here is a video of the E53 (wasn't able to find one from BMW quickly, since they just introduced the mild hybrids), that also uses a camshaft mounted integrated starter generator. As you can see, you press on the button and the engine is just on isntantly.

[Ilyam5]

Originally Posted by Flamingi

How is start stop an inconvenience? How does it change the way you drive?

In stop and go traffic engine shuts off in most inconvenient moments. contrast start and stops make it jerky. In traffic like New York and Boston where you try to close gaps in traffic you need to be on the gas constantly to move forward.
In all the cars ii had - this is the first button i press to disable it constantly and never have it on. So do most of my friends and family members. That is the most hated feature in the performance car.
I want to have an option to turn it off.
Otherwise it will be coded off or i will buy a different car. its that simple.

[Ilyam5]

[Pauloxxi]

Originally Posted by Flamingi

How is start stop an inconvenience? How does it change the way you drive? Keep in mind, they use a camshaft mounter integrated starter, so the engine is turned on instantly, no lag at all compared to the normal start stop systems of the last generation. There is no reason to keep the engine running if you are not using it anyway, so it does not change the way you drive. It is also no inconvenience, because the engine starts when the car in the front moves, as well as soon as you lift your foot from the brake. Since it instantly turns on back again, before you can even move your foot from the break to the accelerator, the engine is running already.

No it isn't. The engine is warm, there is still an oil film left (technically you can run an electric oil pump even if the engine isn't running, idk if that is implemented in BMWs), The ISG turns the engine with 1k rpm, so there isn't any more load than in idle and no higher fuel consumption while starting the engine.

In summary I would say the only downside is the increased weight. It does offer more advantages though, mainly reduced fuel consumption (about 15%, that's quite a lot) and torque boost (significantly reduces turbo lag).

Edit: Here is a video of the E53 (wasn't able to find one from BMW quickly, since they just introduced the mild hybrids), that also uses a camshaft mounted integrated starter generator. As you can see, you press on the button and the engine is just on isntantly.

I don't like the stop start feature and don't use that. Particularly in the winter time my perception is that it kills the battery.
I have short commutes and this engine stop is irritating.
It should be again a personal decision and option.

[EXE46]

Originally Posted by Ilyam5

In stop and go traffic engine shuts off in most inconvenient moments. contrast start and stops make it jerky. In traffic like New York and Boston where you try to close gaps in traffic you need to be on the gas constantly to move forward.
In all the cars ii had - this is the first button i press to disable it constantly and never have it on. So do most of my friends and family members. That is the most hated feature in the performance car.
I want to have an option to turn it off.
Otherwise it will be coded off or i will buy a different car. its that simple.

Buy another car, G22 is one hideous car.

[mcjohnsonsg]

Originally Posted by Ilyam5

In stop and go traffic engine shuts off in most inconvenient moments. contrast start and stops make it jerky. In traffic like New York and Boston where you try to close gaps in traffic you need to be on the gas constantly to move forward.
In all the cars ii had - this is the first button i press to disable it constantly and never have it on. So do most of my friends and family members. That is the most hated feature in the performance car.
I want to have an option to turn it off.
Otherwise it will be coded off or i will buy a different car. its that simple.

Agreed - I can't stand stop start, and neither can my girlfriend. Turning it off is the first thing we both do when we driving the car. And as for fuel economy, I can't believe it really makes the 15% difference previously mentioned unless you're hitting traffic lights every 100yards!

[Flamingi]

Originally Posted by Ilyam5

Your videos exactly proove my point. The M440i (and most other new BMWs) are mild hybrids. They don't use a conventional belt starter.

In the video he literally said the concept works in hybrids. And the M440i is a hybrid... soooo, yeah? Point proven

[Flamingi]

Originally Posted by Pauloxxi

I don't like the stop start feature and don't use that. Particularly in the winter time my perception is that it kills the battery.
I have short commutes and this engine stop is irritating.
It should be again a personal decision and option.

It's a mild hybrid system with two batteries, it will not drain your battery. Also, the voltage is monitored, if it's running low it will just not stop. You think BMW engineers didn't think about such scenarios?

The new mild hybrid system is completely seemless, you will not notice it at all if the engine is turning on or off. Please keep in mind, as I said before, it is not a conventional start stop system. The mild hybrid is the important change in the equation. Just go to your dealer and request a test drive, don't judge before that.

[Flamingi]

Originally Posted by mcjohnsonsg

Agreed - I can't stand stop start, and neither can my girlfriend. Turning it off is the first thing we both do when we driving the car. And as for fuel economy, I can't believe it really makes the 15% difference previously mentioned unless you're hitting traffic lights every 100yards!

The stop start itself only saves about 3-5% of fuel. The whole mild hybrid setup is up to 15% (sailing/coasting as well as earlier engine cut off when coming to a stand still).

[Flamingi]

Originally Posted by Pauloxxi

My bad! I missed the "i" following 440. If it is an hybrid, then the power management an battery are a better setup for stop start engine function.

The i doesn't stand for electric, it still is that famous inline six and can't drive on electric only.

But it has a 48V mild hybrid system, so it is in fact set up better for the start stop.

[zamboni]

MB and VW & Audi were ahead of BMW on the Mild hybrid system, BMW is just catching up with the trend. I'm glad I had an option to turn off this feature on my F80 & E93.

[Flamingi]

I wanted to address the most common points against start/stop systems. To be fair, many points are true for conventional start/stop systems with a normal starter, but most new BMWs are mild hybrids (and in just a couple months it will be all new BMWs), so those points don’t hold anymore. Just as a disclaimer, I’m not arguing for or against start/stop systems (however, I do argue pro mild hybrid), I couldn’t care less if they put it in the car or not. I also don’t care if it’s inconvenient for somebody else, I don’t know you, I don’t give a *** if it bugs you. However, what I really hate are plain false statements. And unfortunately, I did read quite a few of those in this thread, so I want to correct them.

TLDR: BMWs use a mild hybrid setup, the new ̶c̶r̶a̶n̶k̶s̶h̶a̶f̶t̶ ̶m̶o̶u̶n̶t̶e̶d̶ belt driven integrated starter generators are extremely efficient and not inconvenient on startup like older normal starters. All negative points of old systems are addressed with the mild hybrid and additionally, more horsepower and a not unneglectable amount of torque are added. Moreover, a mild hybrid can save 10-15% more fuel than a conventional car in real world tests.
Edit: Mercedes uses crankshaft mounted integrated starter generators which allow for more extra power (that's why they have 22PS more compared to the 11Ps more of the BMWs), BMW uses belt driven starter generators. Doesn't change anything really though...

I really didn’t like the guy in the first video, most of his claims are based on old information, presented in a very biased way and most of all factually wrong. But luckily, that makes it easier for me to disprove. The second video was much better, the guy actually did his research and acknowledges, that most problems you hear about start/stop are non-issues. He is entirely correct with his motivation of the video: conventional start/stop systems don’t give any noticeable benefit to the driver, but only for the lab tests.

Claim: You need a proper battery, lead acid batteries are not good enough for a start stop system.

Yes, a higher capacity battery is beneficial, but lead acid batteries are fine for that use case. In fact, starting, charging stopping is much better for the battery than a deep discharge, as the second guy mentioned. A battery happily starts your engine thousands of times without any issues. You often hear that you should discharge a battery and then charge it fully, often for smartphones etc. but that is wrong. It is much better for the battery to have many small charges than one big charge.
In mild hybrid systems, there is a lithium battery, so that point really isn’t an issue anymore. I find this quote of the first guy very funny in this context:

“They are making cars cheaper and cheaper. They won’t put a more expensive battery in just for the start/stop”

Well, guess what? They did.

In TIS, BMW writes, they use a more powerful alternator as well as a different battery, to address the higher load of the auto start stop system.

A more powerful alternator is installed in conjunction with the automatic engine start-stop due to battery discharge during the engine shutdown. (...)

The automatic engine start-stop is used with the intelligent generator control (IGR). The much more frequent charging and discharging means that the load on the battery is very high.

The cycle resistance of AGM batteries means that they achieve similar results to conventional batteries with regard to service life despite the high load. (...)

The intelligent battery sensor is an extremely important component for energy management in the vehicle network. It is a mechatronics component for monitoring the battery condition. The following measured variables are registered:

• Terminal voltage
• Charge current and discharge current
• Temperature of the battery terminal

Upstream processing of especially time-critical measured variables is carried out by the integrated microprocessor. The results are then forwarded to the Digital Engine Electronics (DME) via the LIN bus.

The software in the Digital Engine Electronics (DME) controls communication with the intelligent battery sensor. Calculation of the battery condition (SOH = State of Health) and also calculation of the state of charge (SOC) is carried out in the Digital Engine Electronics (DME).

In the time between engine OFF and the switch-off of the DME main relay, the intelligent battery sensor receives the following information from the Digital Engine Electronics (DME):

Maximum removable charge for a reliable engine start.
After switch-off of the DME main relay, the intelligent battery sensor continuously checks the state of charge and standby current consumption.

In this press release they also say, the mild hybrids have an additional battery:

Fitting an extremely powerful 48V starter-generator and a second battery significantly enhances the functionality of Brake Energy Regeneration by enabling the energy recuperated when braking or on the overrun to be harnessed not just for powering electrical vehicle functions, but for generating additional drive power.

Claim: Tiny starters are not meant to be used over and over

For context, a non-start/stop car starts about 100k times, a start/stop equipped car starts about 400k times in its lifetime. Yes, your tiny starter of your 1990 Toyota is not meant to be used over and over, but starters of modern cars are reinforced and built to be last about 4 times longer. Why would one claim, that the manufacturers put the very same part in a car, if it is used 4 times as much? Of course they will account for that, so yes, also a conventional starter is meant to be used 400k times in a lifetime. For mild hybrids this is a complete non-issue, since the generator is directly mounted on the crankshaft and has a lot more power.

In TIS, BMW writes an adapted starter is used (This is the case for "normal" start stop systems, since BMWs mild hybrids use an BSG and they write the starter has up to 3kW compared to the 8kW of the BSG):

The starter motor must do more in conjunction with the automatic engine start-stop. The starter motor is therefore configured for a significantly higher number (approximately 8 times) of starting operations. The components of the starter motor have been adapted to the higher requirements.

Claim: Crank and rod bearings are only good for 100k starts

Guy#2 had a viewer send him a question where he said, he learned that starts account for 80% of the wear engine. But in reality, just read above. Of course they also have reinforced those parts… Again, this is not an issue for a mild hybrid, because the BSG cranks up to 1000 rpm instead of the 250 rpm of a conventional starter. This leads to a much reduced load on the parts as well. Also, as guy #2 mentions, if the engine and all it’s parts are warm already and there is oil everywhere, it isn’t really a problem compared to idling.

Claim: You don’t save any fuel

It may not be as much as the manufacturers claim, but based on the fact that a hot engine start doesn’t cost additional fuel (neither for conventional starters, and especially not for mild hybrids) it is quite clear: not running engine = no fuel consumption, idling engine = fuel consumption (yes, minimal but it is there). So this is just not true. For anyone arguing that starts do need more fuel, that’s only the case if the engine is cold. Then, it will need a higher fuel:air ratio, additional cranks to get the oil flowing etc.

Claim: Starting the car is annoying as hell

Well, I can get behind that. It’s probably the only negative point with a start/stop system using a conventional starter. But let’s be real, is it really that annoying? Is it really “crack smoking zombies attacking under the hood” to quote guy#2? But again, with a mild hybrid this is addressed and no issue anymore. The vibration etc. on start is because the starter only does 250rpm and the engine has to get up to idle speed of 1000rpm by itself. With the integrated starter, it will just crank to the idle speed and the engine can start without any effort at all. It is much quicker and you don’t notice it. No vibrations, no lag, nothing.

Guy#2 has a great summary on the issues in his video, so I will base mine on his. There are some issues, but they are mainly miniscule: There is not a problem with the battery, the engine doesn’t wear any faster, you do in fact save a same miniscule amount of fuel. The problem with a conventional start/stop is, that you, as a driver, don’t benefit from it. It literally has no real advantage, except for a lower consumption in the lab test, because there is a disproportionate amount of engine off time.

But this changes when we introduce the mild hybrid setup, that'sa actually something that both guys acknowledge in their videos. It addresses all points: It has a lithium battery, which happily will start your car thousands of times (if you were not convinced that a lead acid battery can do this job as well). It has a powerful (11PS) crankshaft mounted integrated starter generator which is meant to start your engine without any effort and even help you accelerate. Because of this, the engine itself has a decreased load and less wear. The start also isn’t annoying anymore.

Further, it introduces some benefits, e.g. allowing the engine to turn off completely while driving, in turn saving fuel. It has a high amount of torque from 0 rpm, since it’s basically an electric motor, which helps you to accelerate even faster and mitigates the turbo lag. You’re also doing something about the environment, if you care about that.
If we assume the start is not noticeable at all and almost instant (I can only tell you that it is, just request a test drive at your dealer if you want to see it for yourself), the only downside I can see is, that it is another thing that can break. Let me know if you can think of any other downsides.

In total: BMWs use a mild hybrid setup, the new belt driven integrated starter generators are extremely efficient and not inconvenient on startup like older normal starters. All negative points of old systems are addressed with the mild hybrid and additionally, more horsepower and a not unneglectable amount of torque are added. Moreover, a mild hybrid can save 10-15% more fuel than a conventional car in real world tests.

Edit: I will add sources to my statements bit by bit, if I find time for it. Most things should generally be true even without sources though (if you want to belive me).

[joselrl]

Originally Posted by zamboni

MB and VW & Audi were ahead of BMW on the Mild hybrid system, BMW is just catching up with the trend. I'm glad I had an option to turn off this feature on my F80 & E93.

BMW has had mild hybrids for a while as well (and full on plug ins). In Portugal we even have a 316d and 320d with mild hybrid tech (and now the m340d)

[zamboni]

The only advantage on the mild hybrid system is increased torque and limit turbo lag on engine.

[zamboni]

Originally Posted by joselrl

BMW has had mild hybrids for a while as well (and full on plug ins). In Portugal we even have a 316d and 320d with mild hybrid tech (and now the m340d)

These models are only for Europe not available in U.S.

[ovesund]

I would only watch youtube videos from Scotty as entertainment and not as education. What he says is, in my opinion, based on beliefs and not facts.

[Weiner0123]

Wait what?? Am I reading this right the option to turn off Auto Start/Stop is removed?? Good lord I've been turning it off everyday since I got my F30, it's literally become muscle memory... wow I'm glad I didn't wait for the 4 series and just got the G20 3 series..

[mathys]

Is everyone reading Flamingi's excellent info? Up to now I have always disabled start/stop via coding.
However, if it is seemless with the new 48v system, I am willing to give it a chance.

[mcjohnsonsg]

Originally Posted by mathys

Is everyone reading Flamingi's excellent info? Up to now I have always disabled start/stop via coding.
However, if it is seemless with the new 48v system, I am willing to give it a chance.

Yes, I read it all and it's very informative. Problem is, I have never been concerned about the wear and tear issues that Flamingi addresses...I know they aren't really a concern. It is only the annoyance/irritation factor that has made me dislike auto stop-start. It is not just about the fact that you can feel it working, but also about the fact that it makes me feel that the car is in control, not me, at moments when I want control the most,I.e. pulling out into traffic, etc. That might not be completely logical, but it's a bigger factor for me than the vibration, and I can't see it going away with a hybrid system that makes it all work more seamlessly. Having said that, I guess if BMW is taking away the ability to switch it off, then other manufacturers will follow suit and it will become the norm, so I will have to suck it up!

[Pauloxxi]

Flamingi, are you BMW employee, or supplier for BMW powertrain, or working with electric powertrain related to any automotive company?
Your knowledge goes beyond normal Joe and the level of details you explored are not described on any BMW website.