Hypermiling a K10

K

kyle

Can you improve fuel consumption by rolling down hills out of gear?

When I have tried this it seems to have decreased consumption, has anyone else tried?

serious question lol :laugh:
 
Yes, a slightly better method is to simply put the clutch in and Coast down the hill though, then if you do need power fast its simply letting the clutch out.
 
it's considered being out of control of your vehicle and is dangerous. I'd advise you don't do it.
 
uses more fuel as when in gear with no throttle the road is turning your engine so it needs no fuel, if it is out of gear then it has to put fuel in to keep the engine idling.
 
moddedmicra said:
uses more fuel as when in gear with no throttle the road is turning your engine so it needs no fuel, if it is out of gear then it has to put fuel in to keep the engine idling.
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thats exactly what i thought, because the engine is being turned over by the wheels rotating and so on ...
 
nice way to cook your brakes as your going downhill far enough to worrey about mpg

do they not teach you to use the engine to slow down nowdays
 
i remember saying on top gear that when you do engine breaking you are using virtually no fuel so i can understand where modded is coming from
 
in a k10 it will use a little fuel as its carb but still less than out of gear. with a k11 i can confirm that in gear with no throttle uses no fuel as i have an ecu reader.
 
TONEY said:
nice way to cook your brakes as your going downhill far enough to worrey about mpg

do they not teach you to use the engine to slow down nowdays
Click to expand...

they dont teach you to slow down through the gears, only to leave it in gear until your about to stop and then press the clutch
 
i would find just reaking better than going down the gears, less to think about while you are stopping /avoiding stuff. lol just a thought of gearing down to stop would seem like an F1 driver lol
 
I don't get why your out of control of your vehicle if your just coasting (clutch down).

As long as your not speeding etc?

What slight bit of difference does it make?

If you need to stop fast, your clutch is allready down so you would step on the break?

Maybe it's just me.

Pete hopefully will be able to explain :).
 
Oh yes... well I'll try explain.

When the clutch is up you have accelaration and braking. When you clutch is down you have neither. Yes you could hop on the brake but until you hit the brake you have no way of slowing down.

Driving along normally on the throttle, clutch up in gear... see an obsticle... foot off the throttle your engine immediatly provides some braking then you can apply the footbrake if needs be. You only drop the clutch when you come to (or very near to) a complete stop.

I could probably show you a bit better than I can explain it.
 
but.... if you only brake with the clutch down (or in neutral) the front to rear brake bias that the factory design into the car is always constant.
whereas.... depending on how many revs you have when you lift the throttle, or whether the car is front or rear wheel drive, or petrol or diesel, then that brake bias can be very variable (and very dangerous) *geek*
 
But you use your engine as a tool, drive at a suitable speed in a suitable gear for that speed which provides you with the means to accelarate or decelarate. If you're not then you are not in control of that vehicle.

It's not only how I was taught to drive a police car but I understand you'd fail your normal driving test for riding the clutch or coasting in neutral.
 
Yeah I see what your saying..

Basically providing you've got decent anticipation, full control of the car means you are able to avoid an obstacle without use of brakes.

Which makes sense.
 
Pete said:
It's not only how I was taught to drive a police car but I understand you'd fail your normal driving test for riding the clutch or coasting in neutral.
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i dont doubt it pete, i wonder how you stand with an electric car (with no engine braking) eh
when you lift (at high revs) in a diesel, there,s a hell of an extra braking force going into the drivewheels, throwing the f/r brake bias to pot fwn
 
Well you can use your brakes as well as having the engine braking. An extreme example would be descending a large hill, put it in a low gear and use the brakes as well, or in an emergency stop (DO NOT TOUCH THE CLUTCH UNTIL YOU'VE ALMOST STOPPED)... I remember one of my M/Cycle tutors telling me if I touched the clutch when I was doing an emergency stop I mustn't have been doing it right.
 
frank said:
i dont doubt it pete, i wonder how you stand with an electric car (with no engine braking) eh
when you lift (at high revs) in a diesel, there,s a hell of an extra braking force going into the drivewheels, throwing the f/r brake bias to pot fwn
Click to expand...

Not really, the decelaration still throws the cars weight forward and onto the front wheels which do the bulk of the braking (in my car the rear brakes don't do anything unless there is weight on the back end - weird hydraulics)... Yes diesels and petrols have different levels of engine braking but you must still use it. Remember driving is about being in that machine, not someone elses car, you do your test in that punto as if you own 'that punto', you do the checks as if you own that car, you drive it like you own that car.

Electric cars will be a different point in that they'll be automatic (imagine that much torque through a normal clutch?) and most will be fitted with an energy harvesting system (to recharge the batteries) which will act in a similar manner to engine braking.
 
Pete said:
Well you can use your brakes as well as having the engine braking. An extreme example would be descending a large hill, put it in a low gear and use the brakes as well, or in an emergency stop (DO NOT TOUCH THE CLUTCH UNTIL YOU'VE ALMOST STOPPED)... I remember one of my M/Cycle tutors telling me if I touched the clutch when I was doing an emergency stop I mustn't have been doing it right.
Click to expand...

i agree on the long hill pete, you,re gonna get brake fade in those conditions, but why did they have to fit slipper clutches to the motogp 4 strokes ? coz they kept locking up the rear wheel on throttle lift :p

Pete said:
Electric cars will be a different point in that they'll be automatic (imagine that much torque through a normal clutch?) and most will be fitted with an energy harvesting system (to recharge the batteries) which will act in a similar manner to engine braking.
Click to expand...

i think VERY few electric cars have regen :)
 
Thats because of the change of engine speeds being so extreme.

Heres a handy article I googled... http://www.studydriving.com/safety-on-the-road/why-coasting-is-bad/

frank said:
i agree on the long hill pete, you,re gonna get brake fade in those conditions, but why did they have to fit slipper clutches to the motogp 4 strokes ? coz they kept locking up the rear wheel on throttle lift :p



i think VERY few electric cars have regen :)
Click to expand...

There are very few pure electric cars out there... Most at this point are hybrids, most of which have a harvesting system.
 
Pete said:
There are very few pure electric cars out there... Most at this point are hybrids, most of which have a harvesting system.
Click to expand...

i mentioned electric cars not hybrids :grinning: are the 1000 g-wiz cars in london dangerous then ?
 
I certainly wouldn't get into one but thats another issue. I've never driven one so I wouldn't know what they are like but it's not a case of riding it's clutch if it doesn't have one.
 

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