Why are you taught to use Gears to slow down?
- Thread starter Dravinian
- Start date
mattie
missing in inaction
Engine braking used to be recommended as older brake systems were crap both at dissipating heat and at remaining effective at high temps - by using the engine to reduce speed the brakes would be required to do less work and they'd stay cooler at which point they were more effective. Continual use of the brakes on hills could also lead to boiled brake fluid, which permanently harms it.
Modern brakes are both better specified and better at dissipating heat, as well as maintaining effectiveness at high temperatures, so the need for engine braking is diminished (in many cases almost eliminated). Currently engine braking is actively discouraged as it requires you to continually take one hand off the steering wheel. This is seen as undesirable from a vehicle control perspective, although I cannot believe it actually has any significant effect.
It's really just personal preference, it no longer really matters one way or the other. Unless you have an old car.
Modern brakes are both better specified and better at dissipating heat, as well as maintaining effectiveness at high temperatures, so the need for engine braking is diminished (in many cases almost eliminated). Currently engine braking is actively discouraged as it requires you to continually take one hand off the steering wheel. This is seen as undesirable from a vehicle control perspective, although I cannot believe it actually has any significant effect.
It's really just personal preference, it no longer really matters one way or the other. Unless you have an old car.
Yes,that's pretty much what 'Engine braking' is used for.....the whole point is that your 'service brakes' remain fresh,for any unforseen emergency stops. Diesels are best for engine braking,as they have a higher compression ratio. (Can you tell that I'm a mechanic ??).
Engine braking is mostly used in heavy trucks.....if you relied purely on your brakes in a 44 ton artic,you would have NO brakes after about 2 minutes !!
That's why you've seen these stories on TV about 'runaway' trucks...and the terrible carnage they cause. It's due to improper driving... I always remember that 8 wheeler tipper running away going down into Hebden Bridge. It smashed a BT transit straight across the road,into the front of a shop !! Nasty !!
stretchy18
New Member
If you use the "System" control of the vehicle is the most important factor ie two hands on the steering wheel
Modern cars with ABS negate the need to engine/gear brake
The aim is to brake in control and select the correct gear once you have reached the end of your breaking
So approaching a roundabout at high speed in 5th/4th you would brake brake brake, assess situation, select correct gear, move off. If 1st is required you should shift from 5th/4th to 1st etc etc
probably not explained very well, are there any driving coppers out there who could explain clearer
As a PS, it doesnt feel intuitive and needs a bit of practice to feel natural
Modern cars with ABS negate the need to engine/gear brake
The aim is to brake in control and select the correct gear once you have reached the end of your breaking
So approaching a roundabout at high speed in 5th/4th you would brake brake brake, assess situation, select correct gear, move off. If 1st is required you should shift from 5th/4th to 1st etc etc
probably not explained very well, are there any driving coppers out there who could explain clearer
As a PS, it doesnt feel intuitive and needs a bit of practice to feel natural
stretchy18
New Member
No but had a fair bit of driving training of various sorts, including banging round the countryside with copper driving instructors
Have a RoSPA gold advanced driver badge that I wear on my swimmers LOL
Have a RoSPA gold advanced driver badge that I wear on my swimmers LOL
stretchy18
New Member
I am now, unfortunately, the worlds worst passenger! Footwell breaking like a bastard and squawking directions while flinching
Petrolhead
Running in - please pass
I don't disagree, however from a 'control' point of view, you should row down through the gearbox, unless you really are going that slowly that changing down from 5th to 1st will have no impact - in which case you're probably riding the clutch.
A direct shift from 5th/4th to 1st with the associated increase in revs will be hard on the clutch and could result in a bit of unexpected off-roading if attempted on a wet corner.
Another part of it is that you should always be in the correct gear for your speed - Changing down as you slow down means that you are able, if you need to, to immediately accelerate away.
Do they still teach block changes (eg 4th - 2nd) nowadays, or have they got rid of that?
When I was learning to drive, people would ask similar questions about double declutching
ETA: Damn. Page 2, eh? Gah.
Do they still teach block changes (eg 4th - 2nd) nowadays, or have they got rid of that?
When I was learning to drive, people would ask similar questions about double declutching
ETA: Damn. Page 2, eh? Gah.
gentlegreen
I hummus, therefore I am ...
That's how it is for me - second nature to a motorcyclist. I have a horrible feeling that many drivers would be dead if it wasn't for the vast improvements in brakes and tyres.
If they only learned to take full advantage of these improvements rather than seeing them as an excuse for even more careless driving, a lot of other road users would be alive.
onthebrightside
thinking too much
It also means your driving will be smoother which is better for the car and your passengers. It's also much safer in the wet even if you do have ABS.
GarfieldLeChat
fucking awesome but wrong
engine braking is significantly more ecomonical in terms of useage if you are smooth up and down than stop start acceleration maintaining motion and keeping it smooth is bar far the most economical method of using your vechile.
Intrestingly, i've always engine braked and can eek out astionishing fuel savings but when i was taught to race it was something which was considered the norm (along with the smooth drving) however then i took my road licence and they were more concerned with long term engine wear and simple said it's easier to replace brakes than gear boxes, advance driving and police drivign courses will now tell you similar.
as long as you are smoth then no it's not more uneconomical. If you have to break at all then you have already been uneconomical with your fuel as you were going faster than the conditions allowed and you weren't paying suitable attention to the road to judge this (baring emergancies of course) you should aim to break as little as possible.
that isn't to say of course you should tear around like you are in GTA trying to ram others off the road but equally you shouldn't be leaping on the brakes all the time.
Intrestingly, i've always engine braked and can eek out astionishing fuel savings but when i was taught to race it was something which was considered the norm (along with the smooth drving) however then i took my road licence and they were more concerned with long term engine wear and simple said it's easier to replace brakes than gear boxes, advance driving and police drivign courses will now tell you similar.
as long as you are smoth then no it's not more uneconomical. If you have to break at all then you have already been uneconomical with your fuel as you were going faster than the conditions allowed and you weren't paying suitable attention to the road to judge this (baring emergancies of course) you should aim to break as little as possible.
that isn't to say of course you should tear around like you are in GTA trying to ram others off the road but equally you shouldn't be leaping on the brakes all the time.
GarfieldLeChat
fucking awesome but wrong
the more isolated a driver or rider is from the road the larger the false sense of secuirty is...
19sixtysix
Bring me sunshine
Use gears coming down a mountain. I had an engine that was back firing on high revs so I used the brakes coming down the Simplon pass in Switzerland to prevent the backfiring. The T junction at the the bottom of the mountain was interesting. My one and only brake fade experience.
GarfieldLeChat
fucking awesome but wrong
it's an alarming exerince innit... coming of a motorway at around 3 in the morning and a line split all the fuild out on to the road...
jesus that was alarming...
second time in another car we very nearly ended up in a ditch...
19sixtysix
Bring me sunshine
Yep.
Pressing the break pedal you expect action. Fading is weird because your pedal slowly keeps going down and the breaks are trying but its just not really enough. I have to say putting a T juction with a stop sign at the bottom of a mountain pass aint clever and the caravan at the back didn't help. You only do that once though. If my engine back fires now due to high revs and altitude it will back fire all the way down.
GarfieldLeChat
fucking awesome but wrong
second time it happend to me was much clamer than the first although it was that time which nearly cause an accident...
it oh... that's not supposed oh hang bollocks hand break steer pump furiously nothing dammit... hedge ditch well that slowed us down.... everyone alright
had to limp on to tps dads at a leasuirely 15 mph which at a push meant i could have opened the door and stuck me foot out to stop the bloody thing
zippyRN
Orange, Fuzzy, and allowed to possess Cat As
outside a few specailist circumstances this is incorrect ... or perhaps you know better than the body of opinion from the advanced and emergency driving world ...
oh yeah i forget i' on urban 75 so of course 'the system ( of car control)' is a tool of capitalist, spying, nazi thugs ...
free spirit
more tea vicar?
I've actually started free wheeling as much as possible from further out when approaching junctions / needing to slow down in a new fuel conservation mode.
but in normal terms I'd always use a combination of gears and breaks.
IMO it's best to be used to doing this even when not necessary so that you conserve your brakes for when they're needed, are in the correct gear if you do need to accelerate out of it for any reason, and if you ever end up driving a hire car / van that doesn't have abs brakes, you're way less likely to lock up and skid in a hard stop situation if using a combination of gears and brakes.
also I'm pretty sure the time I had a blow out in a van while overtaking a lorry on he motorway that my natural instinct to use a combination of gears and light breaking to slow down gradually and pull over behind the lorry saved me from some major problems.
but in normal terms I'd always use a combination of gears and breaks.
IMO it's best to be used to doing this even when not necessary so that you conserve your brakes for when they're needed, are in the correct gear if you do need to accelerate out of it for any reason, and if you ever end up driving a hire car / van that doesn't have abs brakes, you're way less likely to lock up and skid in a hard stop situation if using a combination of gears and brakes.
also I'm pretty sure the time I had a blow out in a van while overtaking a lorry on he motorway that my natural instinct to use a combination of gears and light breaking to slow down gradually and pull over behind the lorry saved me from some major problems.
free spirit
more tea vicar?
how so?
extra dry
Happy to be here
I think it is more to do with keeping control of the car, rather than hopping on and off the brake pedal. It can be dangerous to the driver behind you..thinking you are about to stop completly then they hit their brakes could lead to an accident...
and of course brake fade..I knew there was good reason to use the gears to slow down
and of course brake fade..I knew there was good reason to use the gears to slow down
GarfieldLeChat
fucking awesome but wrong
GarfieldLeChat
fucking awesome but wrong
by free wheeling do you mean coasting in gear and not 'free wheeling' ie no engauged gear...
because otherwise i cannot think of a more dangerous manner to attempt to control a vechiel than if you were blindfolded...
GarfieldLeChat
fucking awesome but wrong
well you have two things really, one if you have to hit the brakes you'd already bar emergancy misjudged your road conditions it's not economical it's not safe and ultimatly it provided a shitty ride to both you and your passengers.
brake fade really shouldn't happen these days with asbestos (or synthetic asbestos) linings or better as the friction matterial is far more adept at dispersing heat, unless you haven't had them serviced in a while. or you've driven in conditions which have dirtied the pads or disks (lot's of oil heavy rain, mud etc) in which case they can fade but again with usually 2 biting points on the disks this shouldn't be an issue.
where you might also get brake fade is if the disks are warped or have been scored by overly warn brake pads...
gentlegreen
I hummus, therefore I am ...
You actually encounter motorists who take the hint from a flashed brake light ?
My worst experience was in Cornwall last year - especially at night.
GarfieldLeChat
fucking awesome but wrong
You actually encounter motorists who take the hint from a flashed brake light ?
My worst experience was in Cornwall last year - especially at night.
you shouldn't ever flash your brake lights if someone is tailgating you slow down and down and down and down until they overtake you... really why be part of their accident...
gentlegreen
I hummus, therefore I am ...
I do both. In the case of Cornish roads there is frequently no room to pass.
GarfieldLeChat
fucking awesome but wrong
then the fucker behind will just have to wait as you go slower and slower take it to about 15 mph and then apply the brakes and bring it to a stop preferably at a cross roads but so they cannot over take get out leap over one of the hedges and squat down as though you are reliveing yourself see how long it takes for them to stick their head over the wall then scream pervert at them (don't really you'll get into trouble...)
gentlegreen
I hummus, therefore I am ...
That's certainly giving me ideas of what I might put in my back window
