> 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?
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.
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 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.
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
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