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    Coasting?

    I drive a manual transmission Renault clio 1.4 16v 03 plate and I like to coast down gentle slopes as a way of saving fuel. it's not a drastic saving, but I feel every little helps. when I say 'coasting' Ii mean moving with the car in neutral and the engine switched on

    I do this to the disapproval of everyone ever.

    many argue

    1: it reduces my control over the car

    2: it would prevent me from accelerating quick enough to avoid an 'emergency situation' (because I would have to put it in gear before I could accelerate).

    3: I have recently been told that when going down a hill in gear the car uses no more fuel than if I were in neutral, despite the fact that the rpm is greater.

    1: Control: I have not noticed any difference in the handling (steering etc) when coasting, only that I am not slowed by 'engine braking'. does anyone have a solid argument about why coasting reduces control?

    2: 'Emergency Situations': can anyone give me an example of a situation where instant acceleration is the way to avoid such situations?

    3: Third Point: is there any truth to this? surely 1800rpm uses more fuel than 800rpm? furthermore, on a gentle slope if I were in gear and not accelerating, I would decelerate at a greater rate than if I were in neutral, meaning I would have to accelerate more to maintain speed and thus use more fuel. for example, the road to my house is a gentle slope with a 30 limit, I can coast in neutral all the way along this at around 800rpm (or at least significantly less) maintaining a speed of 30. in 5th gear (around 1800rpm when not accelerating), I slow down to 25 after a few seconds, meaning that I have to apply the gas to maintain my speed, and hence use more fuel than if I were coasting.

    any thoughts?

    58 Comments

    OMG!! That is a load of research to a question that doesn't need an answer!!

    to much for me to answer there! but yes i also coast,95% sure it reduces fuel consumption but it does slightly reduce control of car due to no power going to the wheels...

    Banned

    how about parking up and walking the last bit to your house, will save you even more, just a thought - lol

    sassie;5326766

    how about parking up and walking the last bit to your house, will save … how about parking up and walking the last bit to your house, will save you even more, just a thought - lol



    Good Call!!! Or........ a bike?? :thumbsup:

    get a push bike

    dean3988;5326775

    http://www.youtube.com/watch?v=UINOlBtbly4



    youtube.com/wat…vst

    Banned

    cw9652;5326776

    Good Call!!! Or........ a bike?? :thumbsup:



    choc1969;5326779

    get a push bike



    that would involve initial outlay, although you could try freecycle

    Original Poster

    because there's nowhere to park, smartarses!

    i appreciate this seems pointless to a lot of you (the rihanna reference demonstrating this perfectly), but it's more about settling a debate than something i am passionate about

    Original Poster

    wow jessica simpson is dire!

    Banned

    gav989;5326787

    because there's nowhere to park, smartarses!i appreciate this seems … because there's nowhere to park, smartarses!i appreciate this seems pointless to a lot of you (the rihanna reference demonstrating this perfectly), but it's more about settling a debate than something i am passionate about



    was only an idea - lol

    Why go into neutral?
    Cant you just stay in the gear you think is right for the speed you are going at and just keep the clutch down?

    Original Poster

    i've heard (and can actually understand) that this can wear the clutch bearings out. i also heard that when you put the clutch down it floods the engine with petrol and can cause problems it depressed for too long. not sure how true that is though

    gav989;5326787

    because there's nowhere to park, smartarses!i appreciate this seems … because there's nowhere to park, smartarses!i appreciate this seems pointless to a lot of you (the rihanna reference demonstrating this perfectly), but it's more about settling a debate than something i am passionate about



    What, a bike? Just chain it you anything.. (Except a Car) :thumbsup:

    Original Poster

    bike isn't so practical for a 20 mile journey down the motorway though...

    gav989;5326809

    i've heard (and can actually understand) that this can wear the clutch … i've heard (and can actually understand) that this can wear the clutch bearings out. i also heard that when you put the clutch down it floods the engine with petrol and can cause problems it depressed for too long. not sure how true that is though



    Ah well. I guess neutral is a safer bet then.
    I only drove a manual up until I passed my test and since then ive been driving an auto, no clutch to bother about there. I have found myself going into neutral earlier at traffic lights and down hills too in the hope that it saves fuel.

    Banned

    how about getting someone to tow you?

    Original Poster

    sassie;5326822

    how about getting someone to tow you?



    well if you're offering...

    Banned

    gav989;5326828

    well if you're offering...



    i dont drive - lol

    sassie;5326830

    i dont drive - lol



    Do you cycle? ;-)

    Original Poster

    i guess sassie and cw9652 could work together with their push bikes to tow me along

    Banned

    cw9652;5326835

    Do you cycle? ;-)



    nope i walk or catch the bus, common i know but its safer than me driving

    Banned

    gav989;5326838

    i guess sassie and cw9652 could work together with their push bikes to … i guess sassie and cw9652 could work together with their push bikes to tow me along



    i dont cycle either, not doing to well, could you not ask your partner to give you a lift?

    Original Poster

    my partner and i take it in turns to drive. she is the one most concerned with my coasting, there are a lot of in car debates.

    After a car crash one of the drivers is lying injured at the side of the road. 'Don't worry,' said a policeman, a Red Cross nurse is coming to attend to you.'
    Oh no,' groaned the victim, 'couldn't I have a blonde, cheerful one?' :-D

    Banned

    gav989;5326847

    my partner and i take it in turns to drive. she is the one most concerned … my partner and i take it in turns to drive. she is the one most concerned with my coasting, there are a lot of in car debates.



    maybe its best to let them do all the driving and then you wont have to put fuel in your car, problem sorted :thumbsup:

    Original Poster

    almost irrelevant, but jokes are always good. i'll suggest that to her sassie

    Banned

    gav989;5326862

    almost irrelevant, but jokes are always good. i'll suggest that to her … almost irrelevant, but jokes are always good. i'll suggest that to her sassie



    you do that, probs best to duck straight after too, glad i could help x

    gav989;5326838

    i guess sassie and cw9652 could work together with their push bikes to … i guess sassie and cw9652 could work together with their push bikes to tow me along



    If this doesn't make you want to cycle.. Nothing will!

    youtube.com/wat…h-o

    Original Poster

    when did i say i never cycle? i used to do bike trials as well

    Original Poster

    Jumpingphil;5326873

    Anyway, if you are going down hill with the car in gear and your engine … Anyway, if you are going down hill with the car in gear and your engine is doing 1800 rpm, do you think that it is taking in fuel to maintain those revs or could it be the fact that you are going downhill with the car in gear that is causing it.You will probably find that the engine is using little or no fuel when going downhill. I'm assuming you have got you foot off the throttle as it is generally that that determines how much fuel is going in.



    is that similar to the way the pedals would spin on a fixed wheel bike when going down a hill? i like to think of driving in cycling terms...

    i'm not sure if coasting is illegal or not, i believe it is just not recommended, but i could be wrong

    Jumpingphil;5326873

    I thought coasting was illegal..



    Not " illegal " just bad driving, it reduces the drivers control of the vehicle.

    Did any of you " coasters " actually coast during your driving test???? No .. I thought not.;-)

    Inactive;5326898

    Not " illegal " just bad driving, it reduces the drivers control of the … Not " illegal " just bad driving, it reduces the drivers control of the vehicle.Did any of you " coasters " actually coast during your driving test???? No .. I thought not.;-)



    I coasted up to the traffic lights. I assume most people do the same.

    deathtrap3000;5326820

    Ah well. I guess neutral is a safer bet then.I only drove a manual up … Ah well. I guess neutral is a safer bet then.I only drove a manual up until I passed my test and since then ive been driving an auto, no clutch to bother about there. I have found myself going into neutral earlier at traffic lights and down hills too in the hope that it saves fuel.



    You will wreck an automatic gearbox by allowing it to move in neutral, that is why an automatic should never be towed .

    Original Poster

    Inactive;5326898

    it reduces the drivers control of the vehicle



    in what way is the driver's control impaired?

    deathtrap3000;5326900

    I coasted up to the traffic lights. I assume most people do the same.




    Only for a few yards, we are talking about coasting down hill, over a long distance.

    gav989;5326912

    in what way is the driver's control impaired?



    By disengaging the engine braking effect from the drive wheels.

    Original Poster

    but engine braking only slows the car, it does not increase control over the vehicle

    1: it reduces my control over the car
    [COLOR="Red"]Yes, correct. If its more dangerous why do it for the sake of few pennies per mile.[/COLOR]

    2: it would prevent me from accelerating quick enough to avoid an 'emergency situation' (because I would have to put it in gear before I could accelerate).
    [COLOR="#ff0000"]Again safety... but adding to that,
    ~ Which gear would you be in? another 0.5sec's to think, 0.1+ sec to check the speed at which gear is suited, 0.2+ secs to actually put it into gear

    ~ Another 0.5+ sec just as you realised you might be in the wrong gear, either too slow or too fast so your car jolts backwards or forwards (smack the car in front, or let the car behind smack into you, breaking your transmission as you are in the wrong gear)

    ~ Losing sense of grip in the car as the jolt has shifted the weight distribution (in an emergency situation i dont think you'll have time to double de-clutch to smooth out the rev speed)

    ~ Are you actually looking in your rear view or in front while your doing all this? are you checking your options where you need to go next if emergency occurs?
    [/COLOR]

    3: I have recently been told that when going down a hill in gear the car uses no more fuel than if I were in neutral, despite the fact that the rpm is greater.
    [COLOR="#ff0000"]correct. double de-clutching helps solves some questions you may ask RE this.[/COLOR]

    1: Control: I have not noticed any difference in the handling (steering etc) when coasting, only that I am not slowed by 'engine braking'. does anyone have a solid argument about why coasting reduces control?
    [COLOR="RoyalBlue"]Hmm.. a question to anyone out there who may be more informed. does traction control work while coasting? I thought thats linked with engine (i.e. it reduces power to one wheel if its slipping). also, possibly weaker argument.. does LSD work while coasting?[/COLOR]

    If traction control does not work, (if your car as it) then if you slip ur effectively lost a safety feature because you want to save few pennies on fuel.

    2: 'Emergency Situations': can anyone give me an example of a situation where instant acceleration is the way to avoid such situations?
    pass.. but look at ecomiling.com/les…tml, interesting read

    3 - Read up on how to save fuel, coasting is not one of them for sure in any situation. your better off braking early so that you wont need to stop completely for the lights (if you have the space). On saving fuel its as much as perfecting the braking aswell as use of fuel.

    [COLOR="Red"]Braking in such a way you wont need any in traffic jams (i laugh/feel pitty at people who rev up just to move 1 car space every 20secs, try just lifting the clutch slowly?).

    Braking early slowing yourself down slowly (not abruptly) so that perhaps the lights/roundabout is clear by the time you get there so you wont need to pull to a stop? Hate how SO MANY DRIVERS zoom to the junction/roundabout then slam their brakes as if they think the brake is a magical stop button.. Its simply not fuel economical nor safe. Stroll slowly to the junction, as you have more time to look and prepare for entering the road/roundabout.

    For the best smooth eco and/or fast drive the best thing is to look ahead and plan ahead, find all your options, always find an escape option, always be 2 steps ahead of the game.

    If you'd want to know more join advance driving clubs and/or forums and/or do the advance driving test. :thumbsup:[/COLOR]

    Banned

    To answer your question original poster,

    If you have an old car then yes neutral will save you fuel.

    If you have a newish car with an electronic control unit post 1994 cars then it makes sense to have the car in gear. If you read the car manual it actually says the engine uses no fuel in 2nd gear down hill, if you have a really new car it actually charges the internal motor (engine).
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