[condor]

Originally Posted by shancz

True, it cannot. But what I wonder is will the turbo be hot enough to cause any issues in that case ?

Again, the Turbo is at it's normal operating temperature.

The only way out to let the turbo spool down and the oil to settle down seems to be switching off the ESS, waiting and then shut-down of the engine. Looking at all this, I'd rather be without the system, or may be switch it off all the time and do things myself. Flip side of such a vehicle - paying for a feature that I would rarely use.

[tsk1979]

Originally Posted by Jeroen

Again, always check what the manufacturer owner manual says. I would say the chances are they know a lot more than the internet at large!

Jeroen

Yes, they know more and their decision is not based on your peace of mind, but maximizing profitability. So if they can save money to have 100,000 miles reliability instead of 300,000 mile reliability, they will. There is no incentive for them to cater to the people who keep their cars very long. So yes, if you want everything to work great till warranty, then yes, manufacturer advice is great, but if you want to push your vehicle to 300,000 or over, then things need to be done differently from manufacturer.

Remember, even your life is a "pinto analysis" for the manufacturer, where they weigh a safety issues w.r.t whether litigation or a fix will cost more.

[shancz]

Originally Posted by condor

The only way out to let the turbo spool down and the oil to settle down seems to be switching off the ESS, waiting and then shut-down of the engine.
Looking at all this, I'd rather be without the system, or may be switch it off all the time and do things myself. Flip side of such a vehicle - paying for a feature that I would rarely use.

Makes sense.
One concern that I too have is the ESS is explained as a FE enhancing system and is an addon(hence switchable). But I cannot find any connection between the turbo spool down time and the ESS in the manual.

I agree with your view about paying for a feature you rarely use. I guess its more useful in meeting the target FE/emissions for the manufacturer.

I also wonder about the utility of this system itself. Has anyone checked how much of a difference it makes in terms of FE ?

[condor]

Originally Posted by shancz

I agree with your view about paying for a feature you rarely use. I guess its more useful in meeting the target FE/emissions for the manufacturer.

Looks quite the reason to have it in there.

Originally Posted by shancz

I also wonder about the utility of this system itself. Has anyone checked how much of a difference it makes in terms of FE ?

This has been discussed earlier in the micro-hybrid thread. IMO, not enough to offset the cost of such a system. Will be best in an EV.

Btw, before the first Micro-hybrid's came into the market. One system was being developed by an OEM and I had got one unit fitted into my Sumo Victa. Was a nice feature to have at signals, but had to ensure manually that the system is disabled when the signal was going to change soon. Back then we didnt even have the count-down timers that we have now. Simply put, been-there-done-that.

[railfanwithk750]

Originally Posted by shancz

Makes sense.
One concern that I too have is the ESS is explained as a FE enhancing system and is an addon(hence switchable). But I cannot find any connection between the turbo spool down time and the ESS in the manual.

I agree with your view about paying for a feature you rarely use. I guess its more useful in meeting the target FE/emissions for the manufacturer.

I also wonder about the utility of this system itself. Has anyone checked how much of a difference it makes in terms of FE ?

The FE difference will be minimal, unless you are in b2b traffic, where it may give you one KPL extra.

However, one feature which is linked to the ESS is the Torque Boost (in Maruti Suzuki cars) which does make a noticeable improvement in driveability by reducing turbo lag. Having driven a Brezza and the SCross (Diesel versions of both), the difference is evident. That is one reason I do not want to disable the SHVS entirely (which can be achieved easily by using a non-OEM battery).

[shancz]

Originally Posted by condor

Looks quite the reason to have it in there.

This has been discussed earlier in the micro-hybrid thread. IMO, not enough to offset the cost of such a system. Will be best in an EV.

Simply put, been-there-done-that.

Cool, will check out that thread.

Wow, quite an experience.
Instead of the Auto ESS you had a Manual ESS (pun intended).

Although I can foresee that this system will be kept switched off in many cars.

[balenoed_]

The least the manufacture could have done was to have the default state of it to be in OFF position and leave it to the user's discretion to switch it ON when he needs it.

In my last service visit of Scorpio, I insisted the guys to see if they can toggle the state to "OFF by default" though the software. They were about to scratch the head as if they didn't even know what this system does. There I realized it is not going to be possible and they confirmed too in a while that it is not possible.

[GreyNomad]

Originally Posted by railfanwithk750

W.r.t. the ACC, you can actually set the parameter from the MID menu under "IS A/C" option. There are three levels, Economy, Default and Comfortable. With the economy option selected, engine will switch on least often when the Auto Stop is active. With the "Comfortable" option, engine will switch on more frequently to keep the cabin cool.

This is why I love this forum...get to learn something new every time! Thank you for this tip. Will surely try it out asap.

[GTO]

Am a big believer of idling turbos (Why you must practice the "Idling Rule" with Turbo-Charged Cars) & I practice it religiously. What is 60 seconds anyway? Use it to set up the music / climate control when you get in the car, and to pick up your stuff when stepping out.

Am also a hater of idling start-stop systems and have disabled it on my car .

With mass market cars, if manufacturers are given a choice of improving fuel efficiency by 10% & extending the turbochargers life from 125000 to 200000 km (as an example), I can guarantee you they will choose the former. Reason = that's what drives sales & helps them meet FE & emission targets. Hardly any 1st-owner owns his car for beyond 1.25 lakh km anyway, so what difference? No impact on warranty replacement costs either, because of this.

The OEMs spend hundreds of crores of rupees in FE-improvement efforts. Even a 0.2 kmpl difference is life & death for an engineer. A start-stop system is a no-brainer cheap way to increase the numbers, even if it comes at the cost of component life (including but not limited to turbos). I've driven 500 - 600 BHP cars with the stupid idling start-stop system.

End of the day, 99% of enthusiasts will agree that idling doesn't damage anything. But a good number will state that NOT idling can reduce the turbo's life. I prefer to err on the side of safety for my machine which I love very, very dearly . It's like the debate on the running-in period when the engine is brand new. The harshest critics will agree that running-in won't damage engine life. At the same time, believers of running-in firmly think that redlining on day 1 isn't cool for the engine. As you might have guessed, I run-in my new engines very precisely.

[saikarthik]

I am not a right person to comment on turbo systems, but have some experience in designing start stop system. So let me put my opinion and a couple of questions here.

The main reason for turbo damage seems to be due to oil starvation but it doesn't happen in one instance if the duration is less. When the turbo is starved of the lubrication for longer time or frequently the failure can be expected and the starvation of oil at higher RPMs will be more severe due to higher heat generation. When it comes to start stop system, as many said before the system waits for a couple of seconds (3-5 seconds typically) after you shift to neutral and vehicle speed is zero. By this time the turbo RPM would have been reduced and also ensuring oil flow for few seconds. So there should be no problem according to me.

Originally Posted by shancz

I also wonder about the utility of this system itself. Has anyone checked how much of a difference it makes in terms of FE ?

Bigger the displacement, the benefit is more. Typically for 2 to 3.2L engines one can get ~4-5% depending on the duration and frequency of stop.

Originally Posted by railfanwithk750

The FE difference will be minimal, unless you are in b2b traffic, where it may give you one KPL extra.

The disable function is given to avoid irritating driver in bumper to bumper traffic where the vehicle keeps crawling. The system best works in planned urban environment where one gets to a traffic signal, has to wait for say 100 seconds, drives a couple of kilometers and again stops in some signal.

Originally Posted by balenoed_

The least the manufacture could have done was to have the default state of it to be in OFF position and leave it to the user's discretion to switch it ON when he needs it.

In my last service visit of Scorpio, I insisted the guys to see if they can toggle the state to "OFF by default" though the software. They were about to scratch the head as if they didn't even know what this system does. There I realized it is not going to be possible and they confirmed too in a while that it is not possible.

I have worked on Scorpio start stop system and the reason of default ON is to satisfy the requirements laid by the CAFE regulations. Manufacturer can get extra points for keeping the idle start stop function on default ON on every ignition cycle.



It doesn't say explicitly in the attached picture, but there are testing criteria which include it.

[Raghu M]

Originally Posted by railfanwithk750

Considering so days many cars equipped with turbos also come with Idle Start/Stop (A few that quickly come to mind: Ciaz, Ertiga, S-Scross, DZire BS6, Mahindra XUV500, XUV300, TUV300, Hyundai Nios Turbo, and recently Altroz i-Turbo), should this be a cause for concern and should this call for an alternate solution?

Could be a little off topic but I have never encountered the start/stop problem in my XUV300. I switched it off a few weeks ago (after buying), it rarely switches on when I start the engine again. I think you made a great point, curious to see the technicality behind the feature.

[SansGT]

The discussion between whether idling is needed or not is always a topic of debate. I am a believer of the idling principle and thanks to this forum for instilling that habit in me. I did it with my Zest and now with my XUV300. It comes with an idling start stop and though the manual mentions that there are multiple conditions checked before the system kicks in, I always switch it off at the start of the drive. It gives a sense of assurance to that belief which is firm within me.

[SamWilson]

It is a good practice of idling before and after a journey for any engine. May it be turbo charged or NA. Although it is necessary for a turbo more but keeping a habit is good for longevity of engine.

[Vijin]

Another pro turbo idler here.
Xuv300 AMT conveniently doesnt have Start/Stop button, hence no complains. I am guessing the modern synthetic oils with its high burn-off points makes sure there is no coking happening. However, I see a marked difference in smoothness of AMT shifts with just 45 seconds of idling, hence I am planning to continue doing that.

[Jeroen]

Originally Posted by tsk1979

Yes, they know more and their decision is not based on your peace of mind, but maximizing profitability. So if they can save money to have 100,000 miles reliability instead of 300,000 mile reliability, they will. .

As mentioned already, the market for ordinary cars lasting 300.000 miles is minimal. To design and produce cars that last 300.000 miles with the current reliability is going to make each and every car extremely expensive.

I rarely buy a car with less than 100K kilometers on the clock and my Jaguar currently has well over 250K on the clock. There is really no evidence, that not sticking to the normal manufacturing maintenance and service will help to prolong engine life. Earlier or more often oil and oil filter changes really don’t add materially to engine long levity. The one thing I would always be apprehensive about would be parts that are guaranteed for life, because that is usually based on a limited life to say 150K kilometers, give or take. E.g. a sealed for life gear box or steering box. Other than that, proper well executed maintenance and adherence to the owner manual specified instructions will see you through. (E.g. never idle an engine to warm it up when cold).

If you want to extend an engine life, it is best to do so based on a thorough understanding what causes engine wear in the first place.

Originally Posted by shancz

I agree with your view about paying for a feature you rarely use. I guess its more useful in meeting the target FE/emissions for the manufacturer.

I also wonder about the utility of this system itself. Has anyone checked how much of a difference it makes in terms of FE ?

As mentioned by other members it varies. Obviously, cruising on the motorway it does nothing. But it does come into its own in city driving. It depends a bit on whom you would like to believe, but most sources indicate anywhere between 4-12% during city driving.

Originally Posted by saikarthik

The main reason for turbo damage seems to be due to oil starvation but it doesn't happen in one instance if the duration is less. When the turbo is starved of the lubrication for longer time or frequently the failure can be expected and the starvation of oil at higher RPMs will be more severe due to higher heat generation. When it comes to start stop system, as many said before the system waits for a couple of seconds (3-5 seconds typically) after you shift to neutral and vehicle speed is zero. By this time the turbo RPM would have been reduced and also ensuring oil flow for few seconds. So there should be no problem according to me.

I agree, don’t worry about the turbo. Actually, the part that is most at risk are your engine bearings. Because at every start, they wear a little due to initial oil starvation. That is why start / stop engines usually have specially treated cranks, sometimes with special coatings. Allowing less friction at start up and less wear.

Originally Posted by saikarthik

Bigger the displacement, the benefit is more. Typically for 2 to 3.2L engines one can get ~4-5% depending on the duration and frequency of stop.

Thanks, I think it remains a bit of an elusive number, due to the variables. As I mentioned I have come across numbers in the 4-12%.

Originally Posted by saikarthik

I have worked on Scorpio start stop system and the reason of default ON is to satisfy the requirements laid by the CAFE regulations. Manufacturer can get extra points for keeping the idle start stop function on default ON on every ignition cycle.

It doesn't say explicitly in the attached picture, but there are testing criteria which include it.

Thanks for that insight, I was not aware. Far from an expert, so I can only echo what I have read and what I thought made sense; Car manufacturers publish their FE figures according to standardised test and during those test the start/stop feature is on. So the FE and emission numbers are based on having it on. In many countries FE and emission numbers is part of the formal certification of a car that allows it on the roads. It can also determine things like VAT, road tax, so it is a legal requirement that the start / stop feature default position is switched on. Because if it isn’t, it does not meet the criteria under which the car was certified.

Jeroen