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Do you have start stop system turned off?

Discussion in 'Motors' started by Lither, 9 Nov 2020.

  1. Conscript

    Capodecina

    Joined: 18 Oct 2004

    Posts: 10,026

    Location: Kent

    This answers the question regarding how much extra fuel is needed to start the engine as opposed to just letting it idle.
    tl;dw? The amount of fuel required to start the engine was equal to the amount of fuel required to idle for approximately 7 seconds. So if you're sat for any longer than that, then shutting down the engine should save fuel.

    As for long term wear and tear...well, it's a concern, but I doubt very much it's not one that's been factored in by engineers. Also consider that there are some stop/start systems which don't require the starter motor (so no extra wear on that, or the battery), and these systems also don't activate until the engine is up to temperature, so there's no worries about increased wear due to repeated cold starts.

    EDIT: and as Fox pointed out, there's also the benefit that it's more pleasant to have the engine shut off when sat for long periods; not just for the driver, but in urban areas, for pedestrians too.
     
  2. SDK^

    Capodecina

    Joined: 18 Oct 2002

    Posts: 19,378

    and cyclists :)

    *** Run *** :D
     
  3. Jonnycoupe

    Capodecina

    Joined: 19 Oct 2002

    Posts: 13,953

    Location: N.Warks

    Increased hybridisation means theres less metal to metal type restarts. My Discovery Sport with the 48V MHEV is far far smoother than the Velar was with a starter, even more pronounced as diesel high cranking torque and shake through cabin.

    48V so will regen on braking anyway so its not even like you need to find extra energy.

    Its frankly a no brainer in terms of effect on NEDC and WLTP, let alone real world including the reduction in noise of cars idling in traffic.
     
    Last edited: 11 Nov 2020
  4. [TW]Fox

    Man of Honour

    Joined: 17 Oct 2002

    Posts: 158,132

    Depends what you drive. Mine isn't bad but it's noticeable, however the facelift of the current 5 Series is virtually imperceptible.

    Some of you appear to be stuck in 2008.
     
  5. IAmATeaf

    Soldato

    Joined: 3 Apr 2007

    Posts: 7,221

    Location: South of the Watford Gap!

    Can't remember if I've posted before but I did have mine enabled for quite a while but found it annoying, especially when entering a roundabout, it sometimes stopped the engine which caused a few worrying moments. I've since coded mine to be off by default so I have to manually enable it except in Eco mode where it defaults to enabled.

    I watched the CarWow review of the new 440i and that has a system that I would use, battery powered initial launch with the engine kicking in a few seconds later.
     
  6. Cardinal_Fang

    Associate

    Joined: 4 Dec 2013

    Posts: 39

    Location: Warrington

    Yes - because it's pointless. It's only function is to make the official fuel consumption figures look better. The car manufacturers know how the test is run and developed stop-start for precisely that reason.
     
  7. robj20

    Capodecina

    Joined: 9 Apr 2007

    Posts: 10,936

    Well having tried it on both our cars you definitely use less fuel if you let it so it's thing.
    Are the people saying it is no good the same people that think a car that's done 100k is scrap.

    My friend that does starters and batteries tells me there more reliable than standard parts, starters designed to massively out perform standard ones in both power and life.
    Battery systems in cars that look after the battery, though a lot of places when changing a battery don't bother resetting the BMS and this can lead to issues as the car still thinks it has an old battery fitted.

    The Mazda system is perfect, stops the engine with a piston at full compression, then when you want to start injects the fuel and ignites it, no starter involved.
     
  8. Conscript

    Capodecina

    Joined: 18 Oct 2004

    Posts: 10,026

    Location: Kent

    Yes, I agree. They've made the fuel consumption figures look better by reducing the fuel consumption. The bounders!
     
  9. Basher

    Sgarrista

    Joined: 18 Oct 2002

    Posts: 9,152

    It reduced fuel consumption, correct - so has a purpose (as has been covered already).
     
  10. Nasher

    Capodecina

    Joined: 22 Nov 2006

    Posts: 21,817

    Reducing it at the cost of other things :D
     
  11. Jonnycoupe

    Capodecina

    Joined: 19 Oct 2002

    Posts: 13,953

    Location: N.Warks

    citation needed.
     
  12. paintguy

    Mobster

    Joined: 13 Feb 2003

    Posts: 2,799

    Location: Sheffield

    The wife's Tiguan has stop/start. Most of the time it's pretty intelligent so I let it do its thing, but if I know I'm going to have to pull away swiftly I'll just keep the car in gear with the clutch down and it won't cut the engine.

    Since it's been mentioned, I find the hill start assist very useful too, until I get back in my car! I had it on a works Transit Jumbo too, Godsend.
     
  13. matthab

    Mobster

    Joined: 19 Apr 2009

    Posts: 3,158

    Turn it off straight away when I get in the car, I find with the DSG its a little eager turning the engine off. I will enable it if I am stuck in traffic.
     
  14. andy_mk3

    Capodecina

    Joined: 5 Oct 2009

    Posts: 11,537

    Location: Lincolnshire

    I work in the motor trade and have done for 12 years, I have seen zero indication of any extra wear or failures related to stop start.
     
  15. Simon

    Capodecina

    Joined: 21 Oct 2002

    Posts: 24,380

    Location: Berks / Moscow

    Like what ? Come on. Back this one up
     
  16. Dis86

    Suspended

    Joined: 23 Dec 2011

    Posts: 28,576

    Location: Northern England

    Only thing I can think of is the reinforcement of starter motors to deal with the increase in stop-start cycles.
     
  17. Simon

    Capodecina

    Joined: 21 Oct 2002

    Posts: 24,380

    Location: Berks / Moscow

    Nothing the driver would see as a negative though.
     
  18. Dis86

    Suspended

    Joined: 23 Dec 2011

    Posts: 28,576

    Location: Northern England

    Oh I dunno, that extra 150g must really bugger up the handling and acceleration.
     
  19. Simon

    Capodecina

    Joined: 21 Oct 2002

    Posts: 24,380

    Location: Berks / Moscow

    Exactly ! Imagine the extra weight of the button to turn it off too
     
  20. Dis86

    Suspended

    Joined: 23 Dec 2011

    Posts: 28,576

    Location: Northern England

    Christ, didn't even think of that. Although AGM batteries might claw back some weight savings.