[ThatGuyCalledMo]

This is just something I've been wondering about: if you're going at 50mph at gear 5 for example, on say a dual carriageway or whatever and you can see your giveaway/roundabout/exit coming up, do you have to slow down and shift down to gear 4 then 3, then approach the exit at gear 2 or 1? Instead, could one not perhaps hold the clutch down and just slowly press the footbrake and on approach to the exit, drop straight down to gear 2 or 1 (and release the clutch)?

I asked my driving instructor today and he said you should never 'coast' like its some sort of crime. What's wrong with it?

Btw, I've assumed that you do in fact approach a give way/exit in gear 1 or 2 like my instructor says.

Thanks for the help!


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[Einheri]

I coast all the time to conserve fuel. You have less control over your brakes, I think.

[Alexander94]

When I passed the examiner said I coast a lot and that I could have failed for it, because it reduces your control, and according to him doesnt save much fuel in modern cars. I do it all the time now I have passed.

[NuckingFut]

Don't do it whilst learning, as you have less control over the car. The instructor/ examiner will see this as negative and give you a minor for it.

[abcdefghijklmnopqrstuvwxyz]

he tells you never to coast because you will fail your test.... feel free to coast though and keep feeding him money if you wush

[Joinedup]

I don't think it's amazingly bad, i think instructors and examiners take it as a sign you're not controlling the car and maybe having a panic attack.
Don't take it to the next level and switch off the engine while you're moving though because it'll weaken the power brakes and power steering.
The advantage of changing down through the gears is that engine braking slows you down without wearing out your brake linings.

[JC.]

(Original post by Einheri)
I coast all the time to conserve fuel. You have less control over your brakes, I think.

It doesn't conserve fuel at all.

Modern cars will shut off the injectors under engine braking.

[ThatGuyCalledMo]

(Original post by Joinedup)
I don't think it's amazingly bad, i think instructors and examiners take it as a sign you're not controlling the car and maybe having a panic attack.
Don't take it to the next level and switch off the engine while you're moving though because it'll weaken the power brakes and power steering.
The advantage of changing down through the gears is that engine braking slows you down without wearing out your brake linings.

Woah, I would never go as far as to switch the engine off.

Oh right, thanks.


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[ROG.]

(Original post by ThatGuyCalledMo)
This is just something I've been wondering about: if you're going at 50mph at gear 5 for example, on say a dual carriageway or whatever and you can see your giveaway/roundabout/exit coming up, do you have to slow down and shift down to gear 4 then 3, then approach the exit at gear 2 or 1? Instead, could one not perhaps hold the clutch down and just slowly press the footbrake and on approach to the exit, drop straight down to gear 2 or 1 (and release the clutch)?

I asked my driving instructor today and he said you should never 'coast' like its some sort of crime. What's wrong with it?

Btw, I've assumed that you do in fact approach a give way/exit in gear 1 or 2 like my instructor says.

Thanks for the help!


This was posted from The Student Room's iPhone/iPad App

Coasting and dipping the clutch just enough to prevent stalling are two completely different issues

Advanced driving is to stay in current gear until a new gear is required to proceed so that could be going from gear 5 to gear 1 and dipping clutch just enough to prevent stalling

DSA style driving does allow for a 'covering gear' such as 2nd to be used on the approach to a hazard as it allows a little more control for a learner

[Electronica]

(Original post by ThatGuyCalledMo)
This is just something I've been wondering about: if you're going at 50mph at gear 5 for example, on say a dual carriageway or whatever and you can see your giveaway/roundabout/exit coming up, do you have to slow down and shift down to gear 4 then 3, then approach the exit at gear 2 or 1? Instead, could one not perhaps hold the clutch down and just slowly press the footbrake and on approach to the exit, drop straight down to gear 2 or 1 (and release the clutch)?

I asked my driving instructor today and he said you should never 'coast' like its some sort of crime. What's wrong with it?

Btw, I've assumed that you do in fact approach a give way/exit in gear 1 or 2 like my instructor says.

Thanks for the help!

That isn't coasting. In fact, so long as the brake is applied and the car is slowing down, no matter how long your clutch is down for it isn't coasting. You just have to be able to feel the car coming to a stop and not accelerating as you put the clutch down. Coasting is more if you're going round a rounabout and can't be bothered slowing down, just putting down the clutch and letting the car roll round it, or if you're coming into a corner doing the exact same thing. At all times, when the clutch is down, make sure you are applying the brake (unless you are accelerating, of course).

[FXX]

Well firstly as JC said (like I need to reiterate anything he says, but I'm going to anyway) coasting will not save fuel in a modern car. If you dip the clutch and/or flip the gearbox into neutral, the engine needs fuel to run at idle speed to prevent itself from stalling. If you're in any gear, the wheels effectively keep the engine going and so it doesn't need fuel. This can be observed in a car with a trip computer that tells you your mpg from the previous few seconds/metres. When you come off the power but leave it in gear, it will read some astronomically high number or totally off the scale, as no fuel is being pumped into the engine.

Secondly, while I agree coasting isn't necessarily the worst thing in the world, there are situations where it isn't ideal and it is good practice to keep the car in gear and only dip the clutch/change down when you need to. For example, if have the clutch dipped as you are slowing down on the brakes while going downhill (like on many slip roads as you slow down from 70mph), there's quite a good chance your brakes will be overheated by the time you get down to your desired speed. This will mean you have crap/spongy brakes until they've had a chance to cool down. It makes far more sense to keep the car in gear and let the natural friction generated by the internals of the engines slow you down. You aren't placing any wear on the transmission as some people might tell you (unless you change down too early and put load through the synchro mechanism in the gearbox), and you're saving your brakes and a bit of petrol.

Using the engine to slow your car down is also good practice for the first time you drive in snow/ice by yourself, when you should avoid using the footbrake at all.

[FXX]

(Original post by Electronica)
At all times, when the clutch is down, make sure you are applying the brake (unless you are accelerating, of course).

Are you suggesting you should accelerate by letting the car coast downhill? That's unbelievably dangerous, especially if you're a new driver and don't understand how quickly gravity will cause you to accelerate when there's nothing loading the wheels...

[Electronica]

(Original post by FXX)
Are you suggesting you should accelerate by letting the car coast downhill? That's unbelievably dangerous, especially if you're a new driver and don't understand how quickly gravity will cause you to accelerate when there's nothing loading the wheels...

No, I mean, when you are going from 1st all the way to fifth on a normal road you don't brake during the routine haha, at all other times, the brakes should be down when the clutch is down. Sorry for the confusion.

[thelawstudent]

sheeeeesh ppl,

if you've passed your test coast all you like (bearing in mind safety ofc). i do it all the time when i'm approaching a red light. you haven't even passed your test and you're worring about this? satisfy your instructer and the examiner etc but when you've passed, drive how you prefer!!!

[DeeWave]

OK, there are two well-regarded ways of doing that manoeuvre.

1) Apply the brakes in 5th gear to start the vehicle slowing, then press the clutch down at some time during braking as you slow, before the engine starts to shudder. Then hold the clutch down as you're slowing. Once the speed is down to the correct level, release the brakes, move your hand to the gear lever to select the right gear, moving straight from 5th to 2nd, and then lift the clutch and continue driving. This is how I'd usually go about it.

2) Apply the brakes as above, but when you drop the clutch, select an intermediate gear such as 3rd and then lift the clutch again, whilst continuously braking to reduce the speed. Then at the end of braking make a second gear change into 2nd and you're away. This is slightly more flexible and slightly less efficient, but in most situations there really isn't much to chose between the two acceptable approaches.

Neither of these are coasting as such - coasting is usually the term used to mean unnecessarily driving either in neutral or with the clutch down - and in this case the clutch pedal is down to prevent shuddering, stalling, and to make a gear change - a perfectly acceptable use of the clutch! Incidentally, as has been mentioned above, coasting does not save fuel in a modern car relative to driving with no throttle pressure but with the drive still engaged. Apart from using fractionally more fuel, the disadvantage of coasting is that the engine no longer controls the vehicle, so the vehicle's speed can't be adjusted by modulating the throttle. It isn't the biggest sin in the world, but it's entirely pointless and does reduce control a bit.

[Camoxide]

I coast on highways when going downhill. Probably the only time it's worth coasting.

[DeeWave]

(Original post by Camoxide)
I coast on highways when going downhill. Probably the only time it's worth coasting.

If you change into top gear and lift off the power with the drive still engaged, you won't be using any fuel at all. If the slope is so steep that the vehicle threatens to run away and gather pace, simply select a lower gear to control the speed with engine braking.

[Kage]

On a modern car, you don't have to break and go from 5 to 4 to 3 to 2 to 1...

You slow down whilst in 5th, and then hold the clutch in and go to the desired gear.

Coasting is when you put it in neutral, with no gear for a period of time.

Your instructor is teaching you a method that you simply do not need to know.

[Camoxide]

(Original post by DeeWave)
If you change into top gear and lift off the power with the drive still engaged, you won't be using any fuel at all. If the slope is so steep that the vehicle threatens to run away and gather pace, simply select a lower gear to control the speed with engine braking.

It doesn't work at high speed (70). You have to put your foot on the throttle to keep up to speed.

[Schleigg]

(Original post by Camoxide)
It doesn't work at high speed (70). You have to put your foot on the throttle to keep up to speed.

Not if the downhill is steep enough or if you're slowing down, which is what everyone is talking about...