Foxhound5366
Honorary Master
Come on guys n gals, where's everybody else here? Most modern cars have auto stop/start, so are you all just content to let it chow up your engines?
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Auto Stop-Start: Enable/Disable?
- Thread starter Foxhound5366
- Start date
kripstoe
Expert Member
There's very little "rotational" friction during engine operation on the crank and bearings. The "extra" friction you refer to is when the crank is not supported by oil after the engine is switched off, and when it starts up again. Modern engines have low friction bearings and also run with better oils, which should reduce this "extra" friction. In addition to that, the oil is already warm when the start/stop system is activated and the engine should reach the correct oil pressure a lot quicker than when cold, after starting from start/stop event.
kripstoe
Expert Member
That's a little bit dramatic imho. Yes, some components "may" lead a harsher life but they would have been designed to accommodate this. I think some cars don't even rely on the starter to start the engine again.
Anyway, I just switch start/stop off after I start the car, because my stops on the way to work are very short stops.
Tsepz_GP
Executive Member
In my Clio 4 I sometimes turn it Off and sometimes leave it On, it really depends.
For example, this feature is great when sitting at a packed McDonalds Drive-Thru , or when you arrive at a robot that has just turned Red, the car turns off, all is super Quiet and just pleasant for a minute or 5, IMO.
NOW, where I hate this system is e.g. traffic that is moving sporadically and slow, in this case I usually like to go to Neutral when we stop for the 2-3 seconds we are still, and then I forget that SS is On, so the car turns off only for me to depress the Clutch again a second or 2 later, now after doing this 5-6 times the car seems to realise that SS is a bad idea and turns if off itself, but then after a few minutes it's back to doing it, lol, so then I turn it Off.
I doubt it causes much engine wear as thought, from what I feel and hear from my car, the Start that it has in SS vs. the Star that it has when starting it after being turned off completely is very different.
SS start is quicker and almost feels like parts of the car or engine were kept active, and ready to go, vs. How the car starts from being completely off.
That is my experience from a Renault Clio 4.
This makes sense.
In my Clio in actual fact it will not at all activate SS until the engine and battery are at a point it feels are suitable for SS to work. On colder days the car will sometimes not even do SS at all until very late in the journey.
I guess it's down to how it's implemented, in the Jaguar XE 2.0 Diesel we have the SS activates immediately even with a cold engine, while in my Clio 4 it waits for the engine to get warm enough.
For example, this feature is great when sitting at a packed McDonalds Drive-Thru , or when you arrive at a robot that has just turned Red, the car turns off, all is super Quiet and just pleasant for a minute or 5, IMO.
NOW, where I hate this system is e.g. traffic that is moving sporadically and slow, in this case I usually like to go to Neutral when we stop for the 2-3 seconds we are still, and then I forget that SS is On, so the car turns off only for me to depress the Clutch again a second or 2 later, now after doing this 5-6 times the car seems to realise that SS is a bad idea and turns if off itself, but then after a few minutes it's back to doing it, lol, so then I turn it Off.
I doubt it causes much engine wear as thought, from what I feel and hear from my car, the Start that it has in SS vs. the Star that it has when starting it after being turned off completely is very different.
SS start is quicker and almost feels like parts of the car or engine were kept active, and ready to go, vs. How the car starts from being completely off.
That is my experience from a Renault Clio 4.
This makes sense.
In my Clio in actual fact it will not at all activate SS until the engine and battery are at a point it feels are suitable for SS to work. On colder days the car will sometimes not even do SS at all until very late in the journey.
I guess it's down to how it's implemented, in the Jaguar XE 2.0 Diesel we have the SS activates immediately even with a cold engine, while in my Clio 4 it waits for the engine to get warm enough.
Foxhound5366
Honorary Master
Should reduce ... should reach ... not good enough, is it? Not nearly worth it to me, just so BMW can enjoy a low CAFE score. BMW realised that themselves when they issued an authorisation to their dealers to allow the system to at least remember the user's last setting.
Bottom line is that you're going from 50000 starts of an engine to 500000 or more. Better oil and low friction bearings aren't going to counter-balance that 100 percent, and the loss is therefore carried by the motorist (at the very least the third or fourth owner).
HavocXphere
Honorary Master
BMW dealers used to warn against doing this - similar effect as riding the clutch in a manual. That was a couple years back though...auto tech has improved dramatically so it now compensates.I don't bother deactivating mine. On my Beemer (320d) beauty, I brake at a robot but my foot doesn't press down on the brake 100%. It still stops but doesnt switch off. You acquire this skill over time.
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At 3-12% estimated savings I suspect the fuel savings will easily make up for any wear and tear
Besides - certain immediate savings that hit your pocket versus a possible savings down the line (that might be covered under roadplan/next owner) seems like a pretty easy decision to me.
Given that the tech has been in use for close to 10 years I suspect the auto engineers have a pretty good handle on the wear & tear implications and what needed to be upgraded to handle it. If it resulted in "major risk to the engine" they wouldn't do it...
kripstoe
Expert Member
BMW realised what? The people want to switch it off in certain situations? Or am I misunderstanding your point here?
Nothing is going to counter-balance wear and tear 100%. If you're the third or fourth owner of a vehicle, there are many more important things to be concerned about than if start/stop was used. Just search this forum for people who let their cars idle for a couple of minutes every morning to "warm up" before they drive off. How many people do you see let the service station attendant refill oil, without knowing the spec and/or how to check the level?
Foxhound5366
Honorary Master
Why not, Havoc? Look at VW: they lied through their teeth about their diesel emissions, to meet legislative requirements. How about the 'scandal' of the manfuacturers who had to repay motorists swindled by their false fuel consumption claims?
Time and again history has shown us that when business has to choose between its own survival or its clients' best interests, business will choose its own survival. This ties into my earlier point about the European Union's unrealistic emissions legislation and the crazy things that is forcing the OEMs to do just to keep pace: e.g. fitting 1 litre 3-cylinder turbocharged engines to SUVs. The CAFE requirements have also been linked to the adoption of auto stop/start by OEMs: it isn't like they all decided what a wonderful idea this was for their buyers, they were forced to implement desperate measures so that they could remain in business.
To put our full trust in OEMs and their wisdom is a bit optimistic. Also bear in mind that the fuel consumption savings from auto stop/start will be enjoyed by a pre-owned vehicles' first owners, and by the time it comes buyer number three's turn to pick up the can for the extra wear-and-tear bill, he won't have any access to those savings to counter-balance it.
Foxhound5366
Honorary Master
I don't disagree with you, but let's not lose sight of the specific tree in question because it happens to be surrounded by a wood of bad mechanical decisions. My point is simply: is better for me as an individual motorist to keep Auto Stop/Start disabled or is there a significant benefit to me by keeping it on? Obviously *any* extra wear-and-tear on the engine resulting from the system is therefore the primary concern, counter-balanced by direct fuel savings to myself (and here we cannot count the fuel-savings enjoyed by the vehicle's former owners).
HavocXphere
Honorary Master
Given the complexity of modern cars you have exactly zero choice.
If you reckon you can outsmart them with a back off envelope calc based on something random you read go for it. Planned obsolescence is a thing though - it's baked into the cars from top to bottom. So your options are pretty much trust the manufacturer or walk everywhere to avoid wear & tear on the car.
Foxhound5366
Honorary Master
lol, funnily enough even that is not an option because cars end up being damaged by lengthy periods of disuse as well
In this rare instance we do have the ability to deactivate the auto stop/start system permanently, which is still sounding like a good idea (at the very least nobody has claimed that *not* using this system will result in some kind of damage of the car).
kripstoe
Expert Member
Ok... :crylaugh:
HavocXphere
Honorary Master
uhm....reading comprehension?
Foxhound5366
Honorary Master
You don't think that I accurately paraphrased your statement here?
What you suspect, unfortunately, doesn't carry much weight HavocXphere, no disrespect intended. People didn't suspect that VW would lie about their emissions either, but hey ... surprise
Request for thread to be opened again - please keep discussions on-topic, and no personal attacks.
biometrics
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Dave
Honorary Master
More like direct insults, he attacked Sinbad without any provocation right at the start.
Foxhound5366
Honorary Master
Yip, happened to me too: I turned it off, then changed mode into Eco Pro and it reenabled itself! Aargh lol.
I'll definitely get it sorted at the dealership, just to at least remember my setting after ignition off.
Is this for a Beemer? Although it is quite a laugh when someone else drives it and they freak out when it switches off.