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    (Original post by MichaelG)
    how can not having the car in gear, with both feet off the accelerator and clutch use more fuel?
    depends what your driving. Modern engines dont actually use any (or a very minimal amount) of fuel when foot is off accelerator and in gear.

    And also (just guessing) if your in say, third, revs might be at 800. But take it out of gear and clutch up and engine might be idling at 1000.
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    (Original post by JC.)
    Presumably because having your foot on the clutch puts a very slight load on the engine where the release bearing acts against the pressure plate?

    You should really sit there in neutral with the clutch up though as its less wear on the release bearing.
    :confused: when i'm in neutral i dont have my feet on any pedals, the clutch is up..
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    (Original post by Elementric)
    The engine is turning the gearbox, which has frictional losses in it. If you have the clutch down, it isn't.
    Incorrect.
    It's only turning the imput shaft.

    Prove it to yourself. Don't take my word for it.... with the car in neutral, slip the clutch and you'll notice a very tiny drop in revs. This is the load on the release bearing I mentioned earlier.
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    (Original post by MichaelG)
    :confused: when i'm in neutral i dont have my feet on any pedals, the clutch is up..
    Bully for you. You're doing what you're supposed to do.
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    (Original post by JC.)
    Incorrect.
    It's only turning the imput shaft.

    Prove it to yourself. Don't take my word for it.... with the car in neutral, slip the clutch and you'll notice a very tiny drop in revs. This is the load on the release bearing I mentioned earlier.
    With the clutch up, the gearbox side plate is spinning, which presumably is supported by a bearing. With the clutch down, it isn't?
    Ok I'm guessing tiny losses.

    How does the load on the release bearing create a force opposing the rotation of the shaft though, surely it's just a sprung load?
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    (Original post by Elementric)
    The engine is turning the gearbox, which has frictional losses in it. If you have the clutch down, it isn't.
    thats a feature of modern cars though isn't it? i probably should have told you i drive a morris minor, does that make a difference? I've always been told that neutral is the most economic to be in when approaching to stop/slow down (for that car anyway).
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    If you're not sure at the momment then i definitely don't advise rev matching yet - ie when changing down gears applying a bit of gas to match the revs.

    Personally on approach to the lights I would apply lightly the brakes then switch from 4th to 2nd ( rev matching ) in anticipation of the lights changing if the lights were still red then i would roll to a stop then switch it into 1st. - depending if i was at the back of a long queue i would switch to neutral (saves the clutch)

    You could use the old engine breaking technique through all the gears decending from 4th to 1st.

    Or you could slow down then slip it into neutral roll up to the lights n switch back into 1st before you go. - wouldnt advise this if youve not already passed your test because its coasting.


    Once youve got this done perhaps you could try double clutch when moving up through the gears - eg in 2nd gear moving to third - clutch; change into neutral; rev match; change into 3rd;
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    (Original post by Elementric)
    With the clutch up, the gearbox side plate is spinning, which presumably is supported by a bearing. With the clutch down, it isn't?
    Ok I'm guessing tiny losses.

    How does the load on the release bearing create a force opposing the rotation of the shaft though, surely it's just a sprung load?

    What's a "side plate"? :confused:

    With the clutch up, the input shaft is turning inside the box but the layshaft remains stationary.

    When you compress the pressure plate with the release bearing you are putting a load on the engine.
    Its the same principal as when you offer a block of wood up to a sanding disk. The sanding disk slows down and the sacrificial wood is eaten away.
    Think of the flywheel and pressure plate as the sanding disk and the block of wood as the release bearing.

    Seriously... go out to the car and try it for yourself if you don't believe me. The laws of physics wont change.
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    To be honest mate, asking here is stupid. It's all down to experience and the situation. Driving requires adaptation and variation. There is never a set method. It can depend on the gradient for example, whether you can slow in 2nd and cruise straight over or whether you'll have to stop and use 1st, the traffic, and it also depends what you're after. Changing to which gear you want based on the speed you want to carry on at, i.e if you want to rocket maybe 2nd. But if you're slowing down slightly for a while 1 gear might be enough to stop the engine stressing. It's very varied. As you drive more and more, you'll learn what works where and in what situations and apply that.

    We could say use method number whatever on here, but that wouldn't always be suitable. It's very very random and varied. Practice is the only thing you can learn from I think.
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    (Original post by JC.)
    What's a "side plate"? :confused:

    With the clutch up, the input shaft is turning inside the box but the layshaft remains stationary.

    When you compress the pressure plate with the release bearing you are putting a load on the engine.
    Its the same principal as when you offer a block of wood up to a sanding disk. The sanding disk slows down and the sacrificial wood is eaten away.
    Think of the flywheel and pressure plate as the sanding disk and the block of wood as the release bearing.

    Seriously... go out to the car and try it for yourself if you don't believe me. The laws of physics wont change.
    I still don't get why anything is rubbing on anything; when the clutch is down isn't the clutch release plate not spinning, and not in contact with the flywheel?
    It's not the physics, it's the mechanics. And it's not a matter of not believing you, it's a matter of wanting to find out why!

    eh when I said 'gearbox side plate' I meant the clutch disc ( so, the part of the clutch on the gearbox side :o: )
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    (Original post by Elementric)
    I still don't get why anything is rubbing on anything; when the clutch is down isn't the clutch release plate not spinning, and not in contact with the flywheel?
    It's not the physics, it's the mechanics. And it's not a matter of not believing you, it's a matter of wanting to find out why!

    eh when I said 'gearbox side plate' I meant the clutch disc ( so, the part of the clutch on the gearbox side :o: )
    Do yourself a favour.

    http://auto.howstuffworks.com/clutch.htm
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    (Original post by Jarve99)
    Do yourself a favour.

    http://auto.howstuffworks.com/clutch.htm
    Doesn't help. Give better link. All this is telling me is that I still don't understand how when the clutch is disengaged you have a load on the engine.
    The clutch release bearing isn't spinning. The input shaft isn't spinning. How is there any friction acting against the rotation of the flywheel?
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    does anyone else love the feeling when youre in 4th, slow down and then instead of putting it to 3rd and continure to casually accelerate you go 4th-2nd and redline
    just to feel like a badass racing driver for all of about 20 seconds
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    (Original post by AnythingButChardonnay)
    From the modern approach to driving you don't need to change gears at all. Clutch down just before you stop to avoid stalling.
    Ok so you're going 30 in gear 3. You come to a stop , how do you pull off in gear 3. of course you have to gear down. Unless you mean , stop then gear down ?
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    Nvm! I get it now! Didn't realise the whole spring, pressure plate, clutch cover and release bearing spun with the flywheel :o: . noob error.
    Ty for help.
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    I'll just take my foot of the accelerator, then as I get a bit closer I'll use the brake, then as I'm coming to an almost stop, foot down on clutch and into gear 1, parking brake, wait for lights.. ;/
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    (Original post by Pip_x)
    You don't have to but
    Brake and change to 3rd, brake down to 2nd, stop, put it into 1st ready for when you need to move. You can do a double change if you really want but it won't be as smooth.
    poppy **** !

    block changes can be smooth

    odd isn't it that the emergency services, the military, the DSA standards and 'civilian' advanced driving standards all recommend block changing in normal driving of modern cars and light commercials
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    (Original post by SomeonecalledJohnny)
    If I'm being really lazy I take off in 4th as well.
    Is that even possible? Surely it must take an age to get going starting in 4th.
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    (Original post by Cj-Tj)
    So much bad advice.

    It is bad practice to stop in 4th, you should work down the gears and stay in second til you stop.
    INcorrect

    please read 'driving ' and 'roadcraft' before offering any further incorrect driving advice
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    (Original post by Maximum Velocity)
    Ok so you're going 30 in gear 3. You come to a stop , how do you pull off in gear 3. of course you have to gear down. Unless you mean , stop then gear down ?
    yes, stop, handbrake, neutral / starting gear ... unless it's merc or yank car with a pedal parking brake... when you have to go into neutral before applying the parking brake
 
 
 
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