[overtaker]

No amount of sensors can predict when the traffic/car in front of you is gonna move or when you are gonna move. Its impossible.

Originally Posted by clevermax

Idling auto start-stop has to become more 'smart' as a feature, then I would consider enabling it. There are numerous stops that last only for a second or two, and every time engine makes that stop for a few milliseconds and cranks up again, I just cringe. Even though minor, I think about all that wear and tear that it had caused unnecessarily.

The start-stop logic should rely on more real-world data through sensors, and also on the driver's behavior to make a smarter decision to stop only if it is almost certain that the stop is going to last for more than 10 seconds or so.

[amalji]

Originally Posted by d3mon

Idling fuel consumption for a big diesel is around 0.7-1L / hour.

Taking the max number, it means you saved 0.265L every 100KM.

Your lifetime average is 12.3KMPL, which is 8.13L/100KM with start/stop.
Without start stop, it'd have been 8.39L/100KM, which is 11.9KMPL.

So best case, you got about 3.3% benefit from the start stop system. Mind you, this is not including the overhead of starting up, extra drain on the battery (which is charged back up by the engine ), so realistically, it could only be about ~2% overall benefit.

Are you sure about this number ? Reference link

The estimated fuel consumption of an idling engine is 0.6 litres / hr per litre of engine displacement. This means that an idling 3.5 litre engine consumes more than 2 litres of gas per hour. Letting your engine idle 30 minutes a day for two winter months burns a full tank of gas without ever moving a kilometre!

If I use this logic, the Crysta would be burning around 1.68L per hour of idling which translates into 5% fuel savings.

There is another experiment by cartoq.com

The reason why I came back to this thread is because we have a new Yaris CVT in our family and it consistently returns less fuel economy ( 8 - 9 kmpl ) vis-a-vis the Crysta ( 10-11 kmpl ) on same kind of city traffic with a lot of idling. But, Yaris can beat the crysta on fuel economy on highway drives.

[d3mon]

Originally Posted by amalji

Are you sure about this number ?

You seem to be looking at petrol data. Look at diesels specifically.

Many VWs has a nifty indicator that pops up when you are idle - it shows the live L/h consumption. You can read about it on multiple threads like this which confirm that a 2.0TDI consumes about 0.6-0.7L/h. Your crysta's engine is a bit bigger, so it could be slightly higher.

https://forums.tdiclub.com/index.php...idling.306036/

[clevermax]

Originally Posted by overtaker

No amount of sensors can predict when the traffic/car in front of you is gonna move or when you are gonna move. Its impossible.

I believe that sensors alone cannot accomplish this task. I have been thinking about this more, and I believe that some amount of intelligence can be incorporated. For instance, the start-stop system can be disabled when the car is traveling through heavy traffic. This information can be retrieved from real-time traffic data, such as how Google Maps is aware of the traffic conditions.

Additionally, the start-stop system can be programmed to be aware of traffic lights that have a long average wait time of more than 30 seconds. In this case, the system would require location information.

I am confident that the system will continue to evolve and improve over time, as there is no reason for it to remain as rudimentary as it is today.

[AheadAJ]

It's a love-hate relationship. Usually keep it disabled. And switch it on only while approaching red lights which last long. Only gripe is that I have to keep my foot on the brake pedal. Not only it doesn't permit to relax my leg but also keeps the brake-light on, which I am sure is an irritant for the person behind my car.

My wish is that if it could be linked to a combination of gear on neutral and handbrake, it would be "Yay" all the way.

[amalji]

Originally Posted by AheadAJ

. Only gripe is that I have to keep my foot on the brake pedal. Not it doesn't permit to relax my leg but also keeps the brake-light on, which I am sure is an irritant for the person behind my car.

My wish is that if it could be linked to a combination of gear on neutral and handbrake, it would be "Yay" all the way.

Which vehicle do you possess with the the idle start/stop feature?

On my Innova Crysta touring sport diesel AT, I can bring the vehicle to a stop with engine stopped and if i quickly move the gear to P, it stays off even if i release the brakes. The engine restarts if i press the brake pedal again. I found this out accidentally because i was tired of holding the brakes.

[AheadAJ]

Originally Posted by amalji

Which vehicle do you possess with the the idle start/stop feature? I can bring the vehicle to a stop with engine stopped and if i quickly move the gear to P

Thank you. Celerio AGS. Will see if hand-brake thing works in my car.

[Bhodrolok]

Voted Nay. The "savings" really isn't worth the inconvenience and irritation

[Cresterk]

Research shows that turning your petrol car off and then back on saves more fuel than idling if you are stopped for more than 7 seconds.


However, our climate really isn't right for auto-start stop to work well on conventional cars. The AC compressor is tied to the engine and the car turning off leads to the fan blowing ambient air at you if you are stopped for more than a few seconds. An overly aggressive setup also leads to the car turning off when you slow down for speedbreakers or at intersections because it assumes you are at a traffic light and going to come to a full stop.


The exception are hybrid cars which have electrical AC compressors that work off the hybrid battery regardless of whether the engine is running or not. You also don't face that half second lag waiting for the engine to turn on at speedbreakers etc because the electric motor kicks in.

[amalji]

Originally Posted by Cresterk

Research shows that turning your petrol car off and then back on saves more fuel than idling if you are stopped for more than 7 seconds.

Yes, this is correct.

Originally Posted by Cresterk

However, our climate really isn't right for auto-start stop to work well on conventional cars. The AC compressor is tied to the engine and the car turning off leads to the fan blowing ambient air at you if you are stopped for more than a few seconds.

Yes, this has to be well tuned. On the crysta, I just love the setup.

1. Auto start/stop gets engaged only when the cabin temperature is within a range of the target temperature set on the climate control.
2. As soon as the auto stop gets activated, the fan speed decreases so that the cooling from the compressor is retained for longer. Overall, it has been a pleasant experience in my 90000 kms / 5.5 years of using it. Never have I felt the need to disable auto start/stop for the sake of AC.

Note: I do have 3m CR70 applied all around including the front windshield. So that might be of some help as well.

Originally Posted by Cresterk

An overly aggressive setup also leads to the car turning off when you slow down for speedbreakers or at intersections because it assumes you are at a traffic light and going to come to a full stop.

On which vehicle have you seen this ? Never experienced this behaviour ever on the Crysta. You have to be at 0 kmph with the brakes fully depressed and steering pointing straight for the auto stop to activate. So, if I know that there is no point of the engine shutting down, I don't depress the brakes fully even when the vehicle is at 0 kmph and instead keep it depressed only half way.

Originally Posted by Cresterk

The exception are hybrid cars which have electrical AC compressors that work off the hybrid battery regardless of whether the engine is running or not. You also don't face that half second lag waiting for the engine to turn on at speedbreakers etc because the electric motor kicks in.

Agree. Hybrids are the best in that respect.

[noopster]

It's the equivalent of someone else switching off your gas stove while you look away for a moment while cooking! It just irritates the driver and doesn't contribute to saving teh environment in any meaningful way. I hate this feature and thankfully it isn't standard of either of my cars.

[supermax]

I voted Yay, but that's because I drive a stick. I have found that almost 100% of the people who dislike the stop/start system are those who drive automatic cars, and for perfectly valid reasons; I've heard people say that the car switches off even when one is waiting on traffic before turning left. Manuals don't have this issue at all, as the stop/start doesn't switch off the car when the car is in gear and the clutch is down. This means that it only works for me when I slot into neutral, like in a traffic light or a level crossing, and not when I'm waiting to take a left turn. The minute the traffic eases off/clears, I accelerate out instead of first waiting for the engine to fire up. I think stop/starts work great on stick shifts, but should be optional on automatics.

[Cresterk]

Originally Posted by amalji

On which vehicle have you seen this ? Never experienced this behaviour ever on the Crysta. You have to be at 0 kmph with the brakes fully depressed and steering pointing straight for the auto stop to activate. So, if I know that there is no point of the engine shutting down, I don't depress the brakes fully even when the vehicle is at 0 kmph and instead keep it depressed only half way.

The Taigun GT 1.5L had this behaviour which was straight up annoying. I assume that is the same on all new VW/Skoda India 2.0 cars.

[amalji]

Originally Posted by Cresterk

The Taigun GT 1.5L had this behaviour which was straight up annoying. I assume that is the same on all new VW/Skoda India 2.0 cars.

I see. I guess, it has to do with the implementation details which makes it a love or hate. For example, if I were to keep the brake depressed to keep the engine off, I would have hated this feature. But, thankfully some thought have been put on it by Toyota to such an extend that the thing we ( my wife and me ) misses the most in her Yaris is the non availability of idle auto start/stop feature. Manually switching off the engine destroys the fun because your infotainment system goes off as well.

[subraiyr]

Voted Nay

Coming from a Safari to a Jeep AT, i was excited with this feature. One day in a bumper to bumper traffic and i was crying for the stress the engine, the starter kit and associated electronics were going through. I think in India, esp in most of the metros this feature is quite taxing to both vehicles and owners. My first reaction after getting into the car is to switch on the ignition and switch the auto start/stop off