Mike wrote:
> <travisgod@[EMAIL PROTECTED]
> wrote in message
> news:85f0b9db-a9d9-4ce4-bba8-8613beab28ba@[EMAIL PROTECTED]
>>> On modern cars, its LESS than idling. They typically shut fuel flow
>>> OFF on deceleration until the engine speed drops down to idle
>>> speed. So going downhill (in gear) uses zero fuel. Going downhill
>>> in neutral requires the engine to idle, so that would in fact use
>>> MORE fuel than coasting in gear.
>>
>> Your stupidity doesn't QUIT, does it?
>>
>> What if gravity is insufficient to overcome compression losses?
>
>
> Then it wouldn't be much of a hill and you wouldn't be coasting. The
> discusion was about coasting down hill.
Now you're just being silly. What about molehills? You've not considered
molehills. Please try to frame the discussion within a sensible context!
>> In THAT CASE, you are better off ****fting to neutral and letting the
>> engine consume at idle.
>>
>> The engine speed will NOT DROP TO IDLE SPEED, you freakin moron,
>> because the engine is DIRECTLY coupled to the driveline via either
>> the clutch in a manual or the converter lockup (another clutch) in an
>> automatic.
>
> If the transmission is in neutral it is NOT coupled to the driveline
> and WILL be at idle speed.
*Sound of pencil scratching on paper*
>> Try THIS.
>>
>> Put your car in automanual mode. Put it in FIRST GEAR. Evaluate the
>> decleration rate on a LEVEL road from any given speed versus first or
>> second if you do NOT understand engine braking! You will find that
>> RPMs typical of highway speeds in top gear involve actually fairly
>> HIGH levels of engine braking.
>>
>> You should immediately notice DECREASED compression braking when you
>> put the car into 2nd versus 1st. This is WHY you down****ft to slow
>> down.
>>
>> GD, I do this thing every fking day I drive the kids to school. I
>> put the VW into 3rd on a particular decline and let it engine brake
>> to max at <40mph so the cops with lasers at the bottom won't tag me.
>> If I let the transmission select a higher gear or I did so myself, I
>> would exceed the speed limit.
>>
>> The car MAXES out on this decline around 38mph in 3rd gear. If I
>> desire to go FASTER, I MUST use fuel! If I ****ft to 4th, RPMs drop,
>> compression braking lessens and
>
>
> You save fuel because the injectors are shut off and NO fuel is being
> delivered. What part of this don't you understand ?
The part where the injectors are shut off and no fuel is being delivered.
There you go.
> I can roll to a higher terminal speed
>> at which, if I desire to go faster, I must EITHER increase
>> acceleration or decrease deceleration. That could be accomplished by
>> up****fting OR pressing on the accelerator.
>
> Correct. But as soon as you step on the accelerator the ECM turns the
> injectors on and fuel usage resumes. So you use more fuel COASTING IN
> GEAR with your foot off the accelerator.
>
>>
>> EITHER WAY, gravity is competing against engine compression and drag.
>>
>> Do you people even drive cars or are you just idiots? YES, there ARE
>> hills in which drag + engine compression > gravity, therefore you
>> MUST use fuel or ELSE you remove engine compression as a
>> decelerative load! Trav
>
> And you miss the point once again ! The question was "what uses more
> fuel , coasting downhill in neutral or in gear". And the answer is
> coasting in gear uses NO FUEL as the injectors are SHUT OFF in that
> situation.
Now you're just complicating the issue.
--
Wayne Dobson
AKA "Dobbie The House Elf"
|
