Coasting downhill

MrFunex said:
Of course you're in control while coasting, the car's balance and weight distribution doesn't magically change and throw you in a hedge just because the clutch is depressed... What car were you in?
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Eh? The weight distribution and balance changes dramatically. No longer is the car being driven by its own wheels but by mavity/kinetic energy. Whilst you can more or less get away with this in a front wheel drive car... in a rear wheel drive car you are going to come unstuck very very quickly. But even FWD need something to "pull" them through corners. And as such if you try this in a FWD car you will get a lot of understeer...

People that coast down hills with the engine idling are the sort of drivers that will also try to coast round corners when they randomly "can't be bothered"...

This is actually what causes a lot of accidents. Nervous/incompetent drivers... take a corner a bit too fast... realise their mistake so they put the clutch in... all driven wheels stop being driven. Now the car is at the complete mercy of the tyres grip and steering inputs. Often these drivers will also (as if they haven't unsettled the balance enough) hit the brakes as well.
 
I thought it saved fuel to take it out of gear? I got stuck in london's 50mph average speed area and was running on fumes, I didn't think i could make it to the nearest garage, so I kept taking it out of gear to save fuel?...


(I made it tot he garage, but the fuel limiter couldn't go down any further!)
 
Booner! said:
I thought it saved fuel to take it out of gear? I got stuck in london's 50mph average speed area and was running on fumes, I didn't think i could make it to the nearest garage, so I kept taking it out of gear to save fuel?...


(I made it tot he garage, but the fuel limiter couldn't go down any further!)
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When was you taking it out of gear? When rolling to traffic lights etc? If so, bad idea.

Why build up all that kinetic energy (i.e. accelerating) and then just waste it all again when you need to slow down?

To keep an engine idling it needs to keep injecting fuel.

To keep an engine actually turning with no throttle input? Kinetic and/or mavity energy.
 
Pinter75 said:
I was told that it can wear out your thrust bearing quicker...?
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Yes, keeping the clutch pedal depressed for extended periods can prematurely wear the release bearing.

This is going to sound harsh and almost certainly a generalisation, but IME the kind of people that think coasting down hills is a good ideal are the same people who are pretty much clueless about driving in general. Whilst coasting down hill, they will be applying their brakes continuously, and then complain that the pads don't last long. They probably think getting into 5th as quickly as possible is the best thing to do, so change gear at 1700 RPM and ignore the engine trying to escape from it's mountings.
 
Don't be too suprised when you have to emergency brake and you lock up like a tit and go flying into the back of someone...

The ONLY reasons you do not coast is you lose engine braking and the help of the diff to prevent lock.

learn to drive :rolleyes:

edit: even keeping your foot 'hovering' on the clutch wears the release bearing.
 
Dogbreath: I don't think that is a generalisation TBH. It is just fact and you are right. People that think this is a good idea clearly don't have a clue about cars, engines or basic physics.
 
Nope, everyone was going at 50mph in the average speed check area on the motorway. So I got to about 50mph and took it out of gear and rolled till I fell to about 40mph and then wacked it back in gear again every few minutes...
 
Booner! said:
Nope, everyone was going at 50mph in the average speed check area on the motorway. So I got to about 50mph and took it out of gear and rolled till I fell to about 40mph and then wacked it back in gear again every few minutes...
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Why?

Keep it in gear ffs. You would fail your driving test for that.
 
Biohazard said:
Don't be too suprised when you have to emergency brake and you lock up like a tit and go flying into the back of someone...

The ONLY reasons you do not coast is you lose engine braking and the help of the diff to prevent lock.

learn to drive :rolleyes:

edit: even keeping your foot 'hovering' on the clutch wears the release bearing.
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What's funny is that these people will treat it as serious thing if they loose engine power on a motorway...

What they don't realise is there is hardly any difference in terms of safety between idle coasting and suffering an engine cut out.

The only thing being is that the PAS keeps working with an idle engine...
 
Its just plain stupid. Nothing more can be said on the subject. If you coast, you do not know how to drive. I have coasted 5-10 yards before yes, on a flat with no one in front up to lights. Or into a car parking space at low speed.

I don't start randomly coasting on a motorway at 40-50+? :confused: or downhill for that matter, I like having brakes in that situation.
 
There was minimal traffic around and I was running on fumes in an average speed check area..where everyone was doing the same speed as me? I literally just made it to a garage in time... I thought keeping it out of gear would save fuel?
 
Dogbreath said:
Yes, keeping the clutch pedal depressed for extended periods can prematurely wear the release bearing.

This is going to sound harsh and almost certainly a generalisation, but IME the kind of people that think coasting down hills is a good ideal are the same people who are pretty much clueless about driving in general. Whilst coasting down hill, they will be applying their brakes continuously, and then complain that the pads don't last long. They probably think getting into 5th as quickly as possible is the best thing to do, so change gear at 1700 RPM and ignore the engine trying to escape from it's mountings.
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I agree with this 100%
 
For the record, this is the first time that I coasted and only did it for the reason that I was low on fuel and I thought this would save fuel? (need correction here?). I don't hold the clutch down and take the car out of gear at traffic lights rather than sitting on the clutch. I literally did this coasting thing this once to save fuel, whether it worked I don't know... but I made it to a garage with basically no fuel left! I am also aware that you can fail a driving test for it...
 
keeping it at a constant speed will use far less fuel than going 50 - out of gear to 40 - back in gear to 50 etc etc.....acceleration uses the most fuel other than starting :p
 
rG-tom said:
keeping it at a constant speed will use far less fuel than going 50 - out of gear to 40 - back in gear to 50 etc etc.....acceleration uses the most fuel other than starting :p
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That made sense in my head, though I thought the fact that I was going for several minutes before accelerating actually outweighed it tbh. :p
 
Booner just give up now. It does not take friction/grav 'several minutes' to slow you from 50-40, more like seconds.

Please think before you comment. ;)
 
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