Very quick qustion about engine braking vs coasting

[B10Hazard]

If were to be going down a 3 mile stretch of downhill road. What would be more fuel efficient, rolling with clutch in or rolling with engine braking.
I say this as i do a lot of down hill riding on the way to work and a thread on hear that iv just read got me thinking as i always coast with clutch in, and someone on hear ses its better to not coast for fuel economy ?
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Current bike .. The police stole it
No longer any socks
Let me take you on a trip . . let me show the world in my eyes.

[wilz1234]

If your bike is fuel injected then engine braking will give better efficiency as the ecu knows not to put fuel in.
However if it has carbs then when you lift off, itll still be sucking some air through the carbs and therefore using fuel.

[wilz1234]

And if its fuel injected, if you coast it has to put fuel in to keep the engine running

[iooi]

If having the clutch pulled in means you have use your brakes, then it will be costing more in brake pads/disks than it would in fuel.
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Just because my bike was A DIVVY, does not mean i am......

[G]

As above - on an FI vehicle, go for top gear and throttle off if you can. No fuel will be used.

You can consider flicking the engine off with the clutch it, at which point you should also use no fuel.

[B10Hazard]

I get what your saying
Looked how ecu's work for the past 45mins. My cbf 125 is the first fuel injected bike iv owned. Very good so far..
So basically on a all my down hill rides ( when im low on fuel or feeling economic ) its best to sit in 5th with the engine dragging going slightly slower than to roll with the clutch in braking at the bottom of this humungous hill i go down everyday ?
Rolling with the clutch in at 60 i will not be doing less than 50 at the bottom. In 5th doing 60 then revs off letting the engine drag i would be going very slowly by the bottom maybe having to even re aply the throttle now i have explained the hill im sorta wondering how that would save fuel ?
EDIT: So is riding my bike with the engine dragging using less fuel to what my bike would be using sat still on idle ?
____________________
Current bike .. The police stole it
No longer any socks
Let me take you on a trip . . let me show the world in my eyes.

[iooi]

Look at it this way. The diffrence between either way is going to be next to nothing on your 125.

You will save far more by smooth riding, reading the road ahead, so you don't have to use the brakes.
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Just because my bike was A DIVVY, does not mean i am......

[B10Hazard]

I have one of the most economic bikes on the road anyway so im not to fust . Just asking because i seen a debate in a another thread and it got me thinking. How that shit works etc
My usual approach to this massive hill is flying down it as im always late
____________________
Current bike .. The police stole it
No longer any socks
Let me take you on a trip . . let me show the world in my eyes.

[Frost]

Clutch in and roll. On a carbed bike it will continue to pull a little fuel through. If it's FI it won't but either will cause engine breaking and slow you down, but rolling will only have road friction and air resistance.

[Pete.]

The gixxer K7 fuelmap says that it's just not the case that fuel is shut off on coast-down.
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[goto10]

It probably varies between cars/bikes/manufacturers. I read that OBDI shuts fuel down on petrol cars when coasting but OBDII doesn't unless the cat is a certain temperature and the revs are above a certain point. I remember Clarkson doing a test on a diesel some time ago and he said then about the fuel shut-off when coasting (on that particular model), it was after that was on TV that I noticed everyone saying this was the case with every FI car/bike (I'm guessing it wasn't)
But either way, even some fuel is still being used, it won't be much different to idling so you'd be better off keeping it in gear rather than dipping clutch.
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'12 NC700S & '12 CB600F Hornet [Stolen by some dickless twat] Suzuki GT500 shed

[EazyDuz]

when i stop pressing the throttle in my FI car, my Torque app MPG in real time shoots up to something silly like 400 mpg, but i still believe if im going down a steep hill that neutral would wor out better for fuel economy.
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To shreds you say? Tss tss tss

[bazablue]

never coast ...you are not n control if you do and t wears yer clutch out pdq...uote="B10Hazard"]If were to be going down a 3 mile stretch of downhill road. What would be more fuel efficient, rolling with clutch in or rolling with engine braking.
I say this as i do a lot of down hill riding on the way to work and a thread on hear that iv just read got me thinking as i always coast with clutch in, and someone on hear ses its better to not coast for fuel economy ?[/quote]
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early view

[kestrel]

Worth noting that long periods of engine braking on a two stroke that runs pre-mix can cause serious engine damage. With the throttle closed there is only a small amount of fuel/oil mix being drawn through the carb so engine lubrication is greatly reduced.
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Isle of Man.........Road Racing Capital Of The World

[EazyDuz]

[Wafer_Thin_Ham]

[G]

Seen the mpg go to 999 or similar on plenty of fuel economy listings on various vehicles.

[EazyDuz]

[Wafer_Thin_Ham]

[EazyDuz]

[Noxious89123]

[Kickstart]

[EazyDuz]

Doubt it. The hill at half way requires more than a little bit of throttle so it uses a lot more fuel than the momentum of a the car with no engine braking.
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To shreds you say? Tss tss tss

[drzsta]

The day I start worrying about coasting to save fuel will be the day I give up, not like you can get the front up with no throttle
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Current Bikes - BMW S1000RR ‘17 & KTM 690 SMC-R ‘12

[G]

Maybe not, but always impressed by people that can keep it up 'coasting' .