I would like to confirm whether shifting the vehicle to Neutral while at high speed in order to stop the vehicle is bad or not in terms of fuel efficiency. I had a word with some of my collegues and they were saying that, shifting to neutral is just like you are holding the clutch of the vehicle. So, is that true or not.

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    Welcome to the site. The issues of shifting to neutral and engine braking have been discussed at length. Please consider some of the following: mechanics.stackexchange.com/q/678/57, mechanics.stackexchange.com/q/3600/57, mechanics.stackexchange.com/q/4340/57 and mechanics.stackexchange.com/q/816/57.
    – Bob Cross
    Aug 31 '13 at 15:24
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    Shifting to neutral while braking will use MORE fuel since you have to keep the engine turning at idle RPMs without any help from the vehicle's momentum (thus consuming fuel). Aug 31 '13 at 18:09
  • But it DOES improve stopping because you're not fighting the flywheel's momentum too. Sep 1 '13 at 13:00
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    No, it does not. The internal friction of the engine provides much more stopping power than the momentum the flywheel could contribute, and I don't even see how the latter would make sense anyway, even if not for engine friction... Anyone who has misconceptions on this issue is welcome to take their vehicle to an empty stretch of road with a stopwatch and measure the time to decelerate from 60 to 15 or so in gear versus in neutral. Sep 1 '13 at 16:44
  • @R.. is right: anything that can be confirmed through experimentation always wins.
    – Bob Cross
    Sep 1 '13 at 22:30

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