Start stop feature
Senior Member
Joined: Aug 2005
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There is gent on YouTube explaining how to disable that start stop feature with a mid grade scanner. So I’ll have that done at some point. Till then I remember to shut it off as soon as I start the car. I usually let the car idle a minute so I always have ti to remember to hit the button.
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From: Colorado
G550
Information about each manufacturers MH implementation tends to be vague, but it's my understanding that some ISG MH's eliminate the serpentine belt driven components -- alternator, A/C compressor, water pump -- and replace them with electric driven components. Nice for A/C since it can continue to operate in the engine stop mode, but not so nice if a 48V battery problem develops. Without a working water pump, the car necessarily shuts down.
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2019 S560, 2015 Honda Civic Hybrid
My wife's Civic hybrid has a nice feature, a dual A/C compressor with an electric motor inside. When the engine auto-stops, the motor keeps the compressor running.
In max A/C mode, the compressor uses both the belt-drive and the internal motor to give maximum cooling.
In max A/C mode, the compressor uses both the belt-drive and the internal motor to give maximum cooling.
Member
Joined: Jan 2016
Posts: 110
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From: Mt Pleasant, SC
2018 S560
There is a good video I have seen online where an engineer performs a simulation on 2 engines, one of them running constantly and one of them using Start/Stop. They simulated several years of Start/Stop activity in a short period of time and then compared the amount of wear to the engines. The engine that was using Start/Stop showed much more wear than the engine allowed to run. He estimated the Start/Stop could reduce the longevity of the engine by years, and hundreds of thousands of miles.
If you like your car and care about keeping it long-term, always turn off the Engine Start/Stop feature.
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Engine Start/Stop is very bad for engine longevity. It causes excessive wear to engine internal parts due to a temporary loss of oil pressure while the engine is not running. It does not matter if the engine is warm or cold, the loss of oil pressure happens either way. When the engine restarts, it takes a few moments for the oil pressure to ramp up again and bring the internal components into a state of near-zero-wear operation. It is during those few moments that the majority of engine wear takes place. Engine Start/Stop therefore causes the engine to wear sooner than it would if it were allowed to run constantly.
There is a good video I have seen online where an engineer performs a simulation on 2 engines, one of them running constantly and one of them using Start/Stop. They simulated several years of Start/Stop activity in a short period of time and then compared the amount of wear to the engines. The engine that was using Start/Stop showed much more wear than the engine allowed to run. He estimated the Start/Stop could reduce the longevity of the engine by years, and hundreds of thousands of miles.
If you like your car and care about keeping it long-term, always turn off the Engine Start/Stop feature.
There is a good video I have seen online where an engineer performs a simulation on 2 engines, one of them running constantly and one of them using Start/Stop. They simulated several years of Start/Stop activity in a short period of time and then compared the amount of wear to the engines. The engine that was using Start/Stop showed much more wear than the engine allowed to run. He estimated the Start/Stop could reduce the longevity of the engine by years, and hundreds of thousands of miles.
If you like your car and care about keeping it long-term, always turn off the Engine Start/Stop feature.
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Current/Last 5-years:GLS;G70;Alpina B8;X7;Accord. Sold:X7,TeslaS;S560;S550,X5;530e;L.Navigator;LS460
Engine Start/Stop is very bad for engine longevity. It causes excessive wear to engine internal parts due to a temporary loss of oil pressure while the engine is not running. It does not matter if the engine is warm or cold, the loss of oil pressure happens either way. When the engine restarts, it takes a few moments for the oil pressure to ramp up again and bring the internal components into a state of near-zero-wear operation. It is during those few moments that the majority of engine wear takes place. Engine Start/Stop therefore causes the engine to wear sooner than it would if it were allowed to run constantly.
There is a good video I have seen online where an engineer performs a simulation on 2 engines, one of them running constantly and one of them using Start/Stop. They simulated several years of Start/Stop activity in a short period of time and then compared the amount of wear to the engines. The engine that was using Start/Stop showed much more wear than the engine allowed to run. He estimated the Start/Stop could reduce the longevity of the engine by years, and hundreds of thousands of miles.
If you like your car and care about keeping it long-term, always turn off the Engine Start/Stop feature.
There is a good video I have seen online where an engineer performs a simulation on 2 engines, one of them running constantly and one of them using Start/Stop. They simulated several years of Start/Stop activity in a short period of time and then compared the amount of wear to the engines. The engine that was using Start/Stop showed much more wear than the engine allowed to run. He estimated the Start/Stop could reduce the longevity of the engine by years, and hundreds of thousands of miles.
If you like your car and care about keeping it long-term, always turn off the Engine Start/Stop feature.
The point made is that cars with AS/S are already over-engineered to account for that extra restart cycles. Also keep in mind that a hot restart (like at a traffic light) is very different from a cold morning start… most engine wear happens during cold starts, not those brief hot restarts in traffic using AS/S. That’s why AS?S does not work when car is cold sometimes. Bearings and oil film are already in good shape when warm.
For AS/S I think that only component that gets seriously stressed is the battery. I think that’s why most new cars use AGM or EFB batteries (which hare more expensive for us).
There are two parts that I really hate and the real cons for why I think it is unfair for manufacturer to enforce AS/S on us:
1. It is extra cost on our side for something that we get zero benefits from… Advanced battery and additional components baked into the MSRP.
2. It adds vibration/jerkiness
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Actually the majority of good academic papers suggest that the impact of AS/S isn’t as bad as people think. I don’t recall the exact words but I know that even Engineering Explained has generally argued that modern AS/S systems are not the engine killers.
The point made is that cars with AS/S are already over-engineered to account for that extra restart cycles. Also keep in mind that a hot restart (like at a traffic light) is very different from a cold morning start… most engine wear happens during cold starts, not those brief hot restarts in traffic using AS/S. That’s why AS?S does not work when car is cold sometimes. Bearings and oil film are already in good shape when warm.
For AS/S I think that only component that gets seriously stressed is the battery. I think that’s why most new cars use AGM or EFB batteries (which hare more expensive for us).
There are two parts that I really hate and the real cons for why I think it is unfair for manufacturer to enforce AS/S on us:
1. It is extra cost on our side for something that we get zero benefits from… Advanced battery and additional components baked into the MSRP.
2. It adds vibration/jerkiness
The point made is that cars with AS/S are already over-engineered to account for that extra restart cycles. Also keep in mind that a hot restart (like at a traffic light) is very different from a cold morning start… most engine wear happens during cold starts, not those brief hot restarts in traffic using AS/S. That’s why AS?S does not work when car is cold sometimes. Bearings and oil film are already in good shape when warm.
For AS/S I think that only component that gets seriously stressed is the battery. I think that’s why most new cars use AGM or EFB batteries (which hare more expensive for us).
There are two parts that I really hate and the real cons for why I think it is unfair for manufacturer to enforce AS/S on us:
1. It is extra cost on our side for something that we get zero benefits from… Advanced battery and additional components baked into the MSRP.
2. It adds vibration/jerkiness
In regards to auto start/stop on a cold engine, it seems to still turn off the engine on some mild hybrid MBs at least tested on the M254 4-cylinder even shortly after starting.
Member
Joined: Jan 2016
Posts: 110
Likes: 33
From: Mt Pleasant, SC
2018 S560
Also keep in mind that a hot restart (like at a traffic light) is very different from a cold morning start… most engine wear happens during cold starts, not those brief hot restarts in traffic using AS/S. That’s why AS?S does not work when car is cold sometimes. Bearings and oil film are already in good shape when warm.
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Current/Last 5-years:GLS;G70;Alpina B8;X7;Accord. Sold:X7,TeslaS;S560;S550,X5;530e;L.Navigator;LS460
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From: Colorado
G550
Moving parts wear. The more they move, the more they wear. If parts did not wear, a vehicle with 100K miles would sell for the same price as an identical vehicle with only 10K miles.
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Joined: Aug 2005
Posts: 406
Likes: 103
After all these years I’m surprised this is even a debate.
Start stop is bad for the engine and everything in between. With the cost of upkeep for 2nd or 3rd owner I’d be shocked if few MPG mattered to cars owner.
Start stop is bad for the engine and everything in between. With the cost of upkeep for 2nd or 3rd owner I’d be shocked if few MPG mattered to cars owner.
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From: Maryland
2024 S580
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2024 S580
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From: Colorado
G550
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From: Maryland
2024 S580
I don't believe thats evidence of problems with engine start/stop systems in general. That also only shows damage to the starter on that particular BMW, not engine wear damage like people have been claiming. I don't like it either and turn it off, but I haven't seen anything posted on any forums etc that I read that would lead me to believe these systems result in long term vehicle damage in general.
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From: Phoenix
222 S-65
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From: Maryland
2024 S580
I think this feature makes people unreasonably angry (evidence by the fact that Trump chose to target it specifically, he knows what gets under people's skin) and they try and emotionally assign negative outcomes to its existence but I don't see any evidence that there are any.
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From: Phoenix
222 S-65
I think this feature makes people unreasonably angry (evidence by the fact that Trump chose to target it specifically, he knows what gets under people's skin) and they try and emotionally assign negative outcomes to its existence but I don't see any evidence that there are any.
I did the software that remembers last mode. Never have to think about start-stop.
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From: Maryland
2024 S580
In my 222 I had it coded to remember the last setting, in the 223 I have left it coded on because there is no remember last setting. It’s on or off. With the 48v I like being able to let it turn the engine off when I’m waiting to pick the kids up in the carpool line etc. Most drives I turn it off though.
