Stop start on new citigo

[steveeeg]

New car never had stop/start

Works fine no hassles using

Just wondering if it really safes petrol?

Also any more wear on engine etc ?

Wife mainly used for short drive to work only approx 4 miles , so not sure if it's worth just turning it off for her short journey as car will probably not be warmed up and turn on for longer journeys ?

Thanks Steve

[Gyp]

The electronics package is clever enough to only do the stop start thing when the engine is warm enough and the battery has enough charge. They're also clever enough these days to stop the engine at the top of the compression stroke so it can be restarted simply with a spark rather than taxing the starter motor. Very clever stuff.

 

Does it save much fuel? Not really, but it saves you emitting exhaust gasses when there's no benefit whatsoever.

 

It works. It helps your wallet a bit. It helps the environment a bit. Might as well let it do its thing.

[Ootohere]

Stop / start is supposedly to save cars sitting stationary with the engine running, so reduce pollution. 

If your car is sitting parked someplace now it is not using petrol if the engine is off. So same thing if you are sitting stationary in traffic and engine is off.

Maybe the amount will not be noticed though.

Certainly not on a 4 mile trip where the engine / engine oil is not up to temp and it is not economically using fuel anyway.

?

How many miles will you have the car for that engine wear will be a worry.

With 4 mile trips Stop / Start will more often and not work anyway or the battery would have no longevity, or enough power to start the car.

 

[steveeeg]

Many thanks for the replies, really helpfull 

 

clever stuff these modern little cars

 

Cheers Steve

[Zlin]

Give it a good longish run occasionally to keep its battery charged up, especially if the majority of trips are fairly short.

[Emil]

12 hours ago, Gyp said:

They're also clever enough these days to stop the engine at the top of the compression stroke so it can be restarted simply with a spark rather than taxing the starter motor. Very clever stuff.

Where is a the top of the compression stroke as it is 3 cylinder engine? 

 

Anyway it needs starter motor for starting. Spark alone do nothing. 

[snapseller]

Emil,

I believe one of the owner's tricks with the Rolls Royce Ghost (six cylinder side valve) was to start the engine by switching on the ignition. snapseller.

[Blackcountryman]

The system can try your patience,but stick with it,and let it work when needed.The on/off switch is there if your patience runs out.......but only  until you deliberately switch off ignition,then its back on next time.  There is a device available as an add on to over-ride it all together,but this stop start seems to be the trend,even with more expensive cars.

Your saving the planet..........!!!

[Breezy_Pete]

16 hours ago, steveeeg said:

turning it off for her short journey as car will probably not be warmed up and turn on for longer journeys ?

 

Excellent plan. On such short journeys you need to maximise the time the engine is warming up/at operating temperature, and minimise battery use. Kinda the opposite of what will happen any time stop/start is active.

[Tech1e]

4 hours ago, Emil said:

Where is a the top of the compression stroke as it is 3 cylinder engine? 

 

Anyway it needs starter motor for starting. Spark alone do nothing. 

 

In theory if fuel is injected a spark would ignite the fuel causing combustion so the piston would be forced downwards thus starting the engine. All very feasible.

 

Besides with a lot of power trains going hybrid now alternators and starter motors are starting to vanish (depending on the system).

[Emil]

That theory does not work as there is no compressed air-/fuelmixture when engine stops. If there was it will disappear in few seconds. Piston rings can't hold the pressure when engine isn't running. 

 

 

[steveeeg]

asked wife if stop / start activated on her short journey to work and it did not so should not be a problem

 

Car with get a good run on the weekends to make up for the short journeys in the week

 

Cheers Steve

[Bobclive2]

Quote

 

New car never had stop/start

Works fine no hassles using

Just wondering if it really safes petrol?

Also any more wear on engine etc ?

Wife mainly used for short drive to work only approx 4 miles , so not sure if it's worth just turning it off for her short journey as car will probably not be warmed up and turn on for longer journeys ?

Thanks Steve

 

 

Will it save petrol, SLK R171 with no energy saving tech V`s SLK R172  with all energy saving tech (stop/start, direct fuel injection, turbo, regeneration), fuel savings are1.9% for all 4, Honest John (real MPG ).

Also any more wear on engine etc ,  stop/start = 500,000 lifetime cycles,  standard start = 50,000 cycles, do the maths. The statement below was in 2017, ask the dealer in writing whether your bearings have this new self-lubricating material.

(In an attempt to combat this issue, manufacturers are developing a new, self-lubricating material for their bearings, as well as improving the quality of lubricating engine oils.

UK-based company Millers Oils have created a product that is designed to reduce fuel consumption and wear.

Currently, this is only available in their high-end racing oils, but as stop-start engines age, an increased demand could bring the technology into general consumption.)

 

With stop/start you also get smart charging which stops the alternator charging the battery from engine power when state of charge of the battery reaches around 75%, the other 25% gets charged by regeneration, if there is any, short journeys = little regeneration which can cause a flat battery, a partially charged battery shortens it`s life.

[Ootohere]

@Bobclive2

Maybe best just link the Stop / Start 7 or more pages from the Octavia section.

 

The Merc engine stopped is not using fuel, Honest john knows that.  If you start a journey and never need to stop until your destination then Stop / Start will operate 0% of the journey.

[Gyp]

12 hours ago, Emil said:

Where is a the top of the compression stroke as it is 3 cylinder engine? 

 

Anyway it needs starter motor for starting. Spark alone do nothing. 

Err, every cylinder will have a compression stroke, irrespective of how many cylinders there are

 

And perhaps i should have said that the use of a spark to restart augments the starter motor, not replaces it 

[Gyp]

8 hours ago, Wino said:

 

Excellent plan. On such short journeys you need to maximise the time the engine is warming up/at operating temperature, and minimise battery use. Kinda the opposite of what will happen any time stop/start is active.

 

As the s/s doesn't operate until the engine is up to temperature and the battery has sufficient charge, the system is automatically doing what you suggest, so there should be no need to switch it off...

[Breezy_Pete]

If theory and reality were well aligned, you'd probably be right.

However; monitoring the charge level in a lead acid battery 'on the fly' is a very inexact science, and I'm sure I've read that in recent cars stop/start operates virtually irrespective of engine temperature.

[Bobclive2]

Quote

As the s/s doesn't operate until the engine is up to temperature and the battery has sufficient charge, the system is automatically doing what you suggest, so there should be no need to switch it off...

 

It`s linked to smart charging which often leaves the battery under charged, that`s the main reason for stop/start often not  activating, If you like stop/start it`s your choice,  I don`t like it period, even worse if you don`t know whether it`s on or off when entering a busy junction. The gains are marginal unless you are just using it in urban driving, if that`s the case your battery will probably end up  with a low SOC and it won`t work anyway, google (stop/start not working forum) and see what you get. Many drivers are replacing batteries prematurely believing they are bad but are actually just under charged, forum comments are just the tip of the iceberg. 

Edited 4 June, 2019 by Bobclive2

[Bobclive2]

Quote

However; monitoring the charge level in a lead acid battery 'on the fly' is a very inexact science, and I'm sure I've read that in recent cars stop/start operates virtually irrespective of engine temperature.

 

If you purchase a voltage monitor that fits into the cig lighter socket ( £4 Ebay) it will show the charging voltage, with smart charging the voltage will drop to around 12.5 volts and up to around 15 volts, 12.5 volts indicates NO charge into battery, 15 volts is regeneration,  if you don`t get much 15 volt charging there is no regeneration and you end up with a low SOC, a normal charging voltage is around 13.8 to 14.4 volts, with the latter the battery will get a full charge.

[Emil]

57 minutes ago, Gyp said:

Err, every cylinder will have a compression stroke, irrespective of how many cylinders there are

 

And perhaps i should have said that the use of a spark to restart augments the starter motor, not replaces it 

Compression stroke doesn't matter anymore when engine is stalled. There's no mixture and compression which would ignite. It's always another compression stroke needed to start this motor, by starter motor. 

[Ootohere]

@Bobclive2 Where is it that your driving is done in the main?

People on this forum tend to be drivers in many locations and doing different drives so know what Stop / Start can do or not.

There are cities where it might take an hour to get 10 miles or so through and stop / start ca work perfectly well as vehicles might not be going anyplace and that will not be because of people being slow to move when the crawl forward starts.

[Tech1e]

17 hours ago, Emil said:

That theory does not work as there is no compressed air-/fuelmixture when engine stops. If there was it will disappear in few seconds. Piston rings can't hold the pressure when engine isn't running. 

 

 

 

Why would you need compressed air in a petrol engine? The engine isn't in a vacuum so there will be air in the cylinder. Direct injection puts the fuel straight in so if you lit it it would cause combustion. Arguably not the smoothest or best burn but enough to get it going. Not saying it would work on all engines but certainly a low inertia small capacity engine i'd say it could work.

 

Having seen a compression ignition petrol engine running i'm just about ready to believe anything is possible now. 

[KenONeill]

@Bobclive2 Your posts all make sense in theory. IME the term "smart" preficing pretty much any technology is meaningless, if not actually an oxymoron though.

[KenONeill]

47 minutes ago, Tech1e said:

Why would you need compressed air in a petrol engine?

Because, if you don't get compressed air in the cylinder that is on the compression stroke, there will be next to no compression to generate power on the power stroke?

[Bobclive2]

@Bobclive2 Your posts all make sense in theory. IME the term "smart" preficing pretty much any technology is meaningless, if not actually an oxymoron though.

 

Fact, computer controlled charging, aka smart charging controls the alternator, for a fast 15-17 volt regen charge there has to be room in the battery for that high level charge otherwise battery will get overcharged and go bad. City driving does not enable much regen but stop/start is continuously active therefor the battery remains at a low SOC, that`s what`s causing all these flat batteries in cars still under warranty. If you cannot heavily apply the brakes, coast down hill or on the flat you won`t get any regen and the battery can remain at this low partial state of charge which will ruin it. I have now disconnected sensor but before I did that I never used stop start, my car was registered Dec 2011 the battery is stamped 2011 ( 3211 ) and is still good.

 

http://www.batteriesinternational.com/2017/08/10/agm-aftermarket-falters-as-drivers-disable-start-stop-function/  

Edited 5 June, 2019 by Bobclive2