Go Back   Team-BHP > Under the Hood > Technical Stuff


View Poll Results: Your take?
Love it 49 18.28%
Hate it 219 81.72%
Voters: 268. You may not vote on this poll

Reply
 
Thread Tools Search this Thread
Old 23rd April 2017, 11:36   #46
Newbie
 
Join Date: Jul 2016
Location: Bangalore
Posts: 7
Thanked: 16 Times
Default Re: Engine start/stop system - Good, bad or plain rubbish?

Quote:
Originally Posted by Kestrel5915 View Post
How exactly does this water pump save the turbo when one stops the engine immediately after a long hard drive?
Turbos which are water cooled are actually water and oil cooled. So when you shut the engine, the electric water pump continues to circulate the water so that the oil does not absorb all the heat and coke up. The latter is what causes the turbo to fail and why it is recommended to let the engine idle after a fast run.
saur95 is offline   Reply With Quote
Old 23rd April 2017, 17:50   #47
BHPian
 
Kestrel5915's Avatar
 
Join Date: Mar 2017
Location: Noida
Posts: 70
Thanked: 61 Times
Default Re: Engine start/stop system - Good, bad or plain rubbish?

Quote:
Originally Posted by saur95 View Post
Turbos which are water cooled are actually water and oil cooled. So when you shut the engine, the electric water pump continues to circulate the water so that the oil does not absorb all the heat and coke up. The latter is what causes the turbo to fail and why it is recommended to let the engine idle after a fast run.
That much I know but when does this pump stop?
Kestrel5915 is offline   Reply With Quote
Old 24th April 2017, 22:54   #48
BHPian
 
Nohonking's Avatar
 
Join Date: Mar 2017
Location: UK08 et HR26
Posts: 143
Thanked: 448 Times
Default Re: Engine start/stop system - Good, bad or plain rubbish?

Voted: Love it

The reasons in support: Let us not think only from the wear and tear perspective or purely as a matter of money. Knowing that the fossil fuels are limited, if say a thousand cars in a city, each saving 30ml of fuel each day by the way of auto start/stop function, the total amount of fuel saved is 30 litres everyday, which is almost a good full tank. Now consider this happening in 15 major cities for 365 days. Almost 5,500 additional cars get their tanks full only from the savings.

Coming to the downsides pertinent to wear and tear. IMO, in a normal contemporary gasoline engine, once heated up after the first cold crank in the morning, there will be barely any wear. Yes, common rail diesels and the turbocharged engines may have a fair chance to suffer due to this. Further, turbochargers kick in only after the engine has reached certain RPM, which IMO in a snarling city traffic won't be the case.

Coming on to air conditioning, the compressor will stop along with the engine, but since the coil is still cool enough, the bare blower will continue to cool unless the stoppage is too prolonged. Besides, the other downside is the extra time lag as the stopped engine again has to come to life, but then somewhere one has to compromise in order to save the precious fossil fuels and live to drive more. Thanks.

Last edited by Nohonking : 24th April 2017 at 23:19.
Nohonking is offline   Reply With Quote
Old 24th April 2017, 23:41   #49
BHPian
 
Kestrel5915's Avatar
 
Join Date: Mar 2017
Location: Noida
Posts: 70
Thanked: 61 Times
Default Re: Engine start/stop system - Good, bad or plain rubbish?

Quote:
Originally Posted by Nohonking View Post
.Further, turbochargers kick in only after the engine has reached certain RPM, which IMO in a snarling city traffic won't be the case.
Turbo is turning all the time when the engine is running.
The boost kicks in at a certain RPM.
Kestrel5915 is offline   (1) Thanks Reply With Quote
Old 25th April 2017, 13:46   #50
BHPian
 
Join Date: Apr 2009
Location: Bangalore
Posts: 180
Thanked: 260 Times
Default Re: Engine start/stop system - Good, bad or plain rubbish?

Quote:
Originally Posted by Nohonking View Post
Voted: Love it
Theoretically, your reasoning is right. But, this Cost benefit analysis wont be complete unless there is a thorough analysis done on the cost of
1. Battery life
2. Engine /starter wear and tear,
3. Fuel wastage of other vehicles waiting behind a vehicle due to malfunctioning of the current module and vehicle not starting in a running traffic where there is a queue of several vehicles behind the vehicle that has stalled !
4. Cost of fuel wastage due to AC switching off when vehicle is off and temperature going up in the vehicle and to bring back the temperature to set temperature, the extra amount of AC to be run and extra fuel consumption.


Last edited by gkveda : 25th April 2017 at 13:47.
gkveda is offline   Reply With Quote
Old 25th April 2017, 22:00   #51
Newbie
 
Join Date: Jul 2016
Location: Bangalore
Posts: 7
Thanked: 16 Times
Default Re: Engine start/stop system - Good, bad or plain rubbish?

Quote:
Originally Posted by Kestrel5915 View Post
That much I know but when does this pump stop?
I believe it runs for about 45-60 seconds thereby making up for not idling for what would be around the same amount of time
saur95 is offline   Reply With Quote
Old 2nd May 2017, 17:30   #52
Senior - BHPian
 
Join Date: Oct 2012
Location: Delhi
Posts: 2,918
Thanked: 5,778 Times
Default Re: Engine start/stop system - Good, bad or plain rubbish?

Some real time data:

I took the new Suzuki Ignis out for a test drive this morning. It has a start/stop system. It also displays how much fuel it has saved!

So this was a brand new Inis Style, used as demonstrator. It had 173 km on the clock. Here in the Netherlands potential customers would get this car, bum around for 30 minutes or so. Bit of motorway, but always lots of city driving in the The Hague area.

So after these 173 km, it showed the start/stop had saved 254mg of fuel. That is so little you might as well not bother.

Not quite sure how relevant the above number are. First time I saw an indicator for fuel saved on these start/stop types.

Jeroen
Jeroen is offline   (3) Thanks Reply With Quote
Old 9th May 2017, 19:18   #53
Senior - BHPian
 
Sn1p3r's Avatar
 
Join Date: Jul 2009
Location: Germany
Posts: 1,036
Thanked: 223 Times
Default Re: Engine start/stop system - Good, bad or plain rubbish?

I have not voted for I feel differently depending on the situation of traffic.

1. If the engine is not hot enough (winters in sub 0 deg) the system does not activate. The AC is not required ( <> heating load).

2. In manual cars it is a pain for the gear sync to car start is not always ok, in automatic not so much as the OBC does all the work.

3. After a long hard drive after the autobahn (say 2 hours) the features brings some peace of mind. This is because the exits are so designed to slow down and cool off the turbos (in India I don’t see that happening. So the start stop is like a jolt as the AC is constantly required.

4. Most important this system was a part of smart city masterplan. The Internet of Things (IoT) will bring about hopefully in few years time the connections between the infrastructure and cars so that the cars would know when the lights will be green and what speeds to go for getting all greens in a city. In Germany, the autobahn speed control works automatically as the congestion on the arteries or exit points add up, now add this to the start-stop and it is a boon and saves a lot of lives (environmental) and some fuel too.

The tech will catch up and then we all can love this niggle. Right now it is a hassle I am living with before everyone is forced to board a self driving car.
Sn1p3r is offline   (1) Thanks Reply With Quote
Old 22nd May 2017, 08:46   #54
Team-BHP Support
 
Join Date: Feb 2004
Location: Bangalore
Posts: 11,724
Thanked: 9,036 Times
Default Re: Engine start/stop system - Good, bad or plain rubbish?

Another stupid thing that happens which I read about over the weekend

Source

Quote:
Running on empty
I am a full-time car-park attendant at a large hospital and have noticed with modern cars now there is a new driver-error where on push-button, stop-start models, an owner can lock the car, walk off to work and leave the engine still running. A new 66 plate BMW did just this for over 2 hours last week, until I managed to trace the owner, due to a windscreen permit in his car. I find this a dangerous practice as the car was getting very hot and also what a waste of fuel. I did not manage to speak to the owner, but a 65 plate Mini did the same thing this week. The car was locked, but the engine was running for over 3 hours. Your thoughts please.

RO, Appleby, Cumbria
Reply
Quote:
I've done it myself. The stop start system shuts off the engine. You then get out and lock the car. But because you haven't pressed the stop button, the engine then re-starts when it needs to in order to charge the battery. I agree. Even more ridiculous are proximity sensing systems. If an owner is nearby but out of range of the sensor, a thief can use a signal amplifier to amplify the signal from the key to the car, then get in and drive the car away. Totally nuts.

Last edited by ajmat : 22nd May 2017 at 10:29.
ajmat is offline   Reply With Quote
Old 24th May 2017, 17:31   #55
BHPian
 
SamuraiJack's Avatar
 
Join Date: Dec 2008
Location: Bangalore
Posts: 167
Thanked: 124 Times
Default Re: Engine start/stop system - Good, bad or plain rubbish?

Quote:
Originally Posted by i74js View Post
Loving something like this was difficult, this feature is not present in any of my cars but have seen it happening with a friends Ciaz and it is downright irritating.

No mater how much I would like to save the fuel, the requirement of air conditioning in Indian conditions does not warrant this feature for at least 7 to 8 months in a year (Summers and Monsoons). More so I was particularly irritated that this cannot be programmed for "permanent off condition" as was told by friend.

Even in winters, when the car has just started and I come out of my society, it switches off (within say 100 meters of my apartment) when I want the engine to run, so as to warm up to the operating temperature; the engineers would have programmed it for such conditions that auto-off will not come into play unless the car reaches its operating temperature, but even that has not been thought off.

The SHVS and Microhybrid were just used as tools to get the FAME benefit, which has now been withdrawn for these technologies starting April 1, 2017.

In Ciaz (not aware of M&M), the SHVS does not even have a quality battery, just a different 48 volt lead acid battery from Exide has been placed which the sales advisor says has been specially manufactured for MSIL.

In all its a redundant feature, rather a marketing gimmick for claiming additional mileage and reduced taxation. There are discussions about reduced emissions; can a technical study confirm this in a stop and go traffic of Delhi, Mumbai, Bangalore etc.? This may be possible in ideal / test conditions.

Advantage to the customer? or long term impact on the engine and its components - well not known, personally I would consider it detrimental to the health of car.

I believe its the energy in the battery that decides/triggers the start stop, although considering cold starts would have been good addition.
SamuraiJack is offline   Reply With Quote
Old 28th May 2017, 08:06   #56
BHPian
 
Heavy Horse's Avatar
 
Join Date: Nov 2012
Location: Mumbai
Posts: 267
Thanked: 273 Times
Default Re: Engine start/stop system - Good, bad or plain rubbish?

Quote:
Originally Posted by ajmat View Post
Another stupid thing that happens which I read about over the weekend.

XUV owners will not agree with these descriptions. The start/ stop happens only if you press/un-press the clutch/brake. If you want to park, come to neutral, pull the hand brake and take your feet off the pedals, the car stops in seconds. Off course any sensible driver should ensure that the car engine is off before he disembarks and leaves.



Reply[/quote]

Quote:
Originally Posted by SamuraiJack View Post
I believe its the energy in the battery that decides/triggers the start stop, although considering cold starts would have been good addition.
Not to my knowledge in XUVs. See above for description of the workings in an XUV.
Heavy Horse is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
PIC : Tata Nano with Bosch Start / Stop system stable rock The Indian Car Scene 6 1st July 2010 01:41
Bosch start stop system gigatech2006 Technical Stuff 1 11th December 2008 12:02
British rubbish 'dumped' in India aerohit Shifting gears 3 16th October 2008 00:58
Drag Mods in India....good,bad or just plain ugly MustangMan Modifications & Accessories 20 25th March 2005 15:55


All times are GMT +5.5. The time now is 04:57.

Copyright 2000 - 2017, Team-BHP.com
Proudly powered by E2E Networks