Is changing down through the gears a bad habit
Discussion
Free flowing traffic, car ahead wants to turn and needs to stop. There's a big enough gap that if you work your way down through the gears and feather the clutch you can slow down to the appropriate gear to pull away again without braking. Is this a bad habit that I've got into. Should I brake and not change down through the gears? I only change down if I can use the gear / get the clutch fully up. In situations with a car following closely or on fast roads (or where a quicker stop is needed) I would brake and change down.
HustleRussell said:
Clutch plate wear? depends how good your rev matching is. Clutch cable / slave cylinder / release bearing / pedal mechanism / clutch switch wear? inevitable with more gear changes I suppose. Gear synchro / selector mechanism wear? again, inevitable with more changes I suppose.
Whether the life span of any of these components is going to be reduced appreciably by the additional gear changes, how would you ever know?
Personally I do it anyway, if that means I need a clutch kit after 190k rather than 200k so be it.
I was taught to brake and not change down through the gears, at some point soon after passing I started to change down instinctively and the habit stuck. I've given it a go last night and this morning on my commute and dipping the clutch around 800 rpm means the majority of engine braking still applies. I'm struggling to override muscle memory but not changing down does make approaching easier, I'm still selecting the next onward gear to accelerate out of the gap. I'll ask the IAM experts next year when I start going along to meetings!Whether the life span of any of these components is going to be reduced appreciably by the additional gear changes, how would you ever know?
Personally I do it anyway, if that means I need a clutch kit after 190k rather than 200k so be it.
NDNDNDND said:
Learn to heel n' toe.
It's nice to be in the correct gear when the car moves out the way and I accelerate away in the correct gear while the car behind fumbles with the clutch.
As for wear, I changed out a clutch in a car I've driven like this for ten years. The clutch was changed because the pressure plate strap had failed and was flailing inside the bell housing. The clutch friction disk was barely half worn, at 150,000 miles.
I've read the theory on heel & toe but haven't had a situation where I've thought I would need it. Saying that, I don't really know what I'm looking for. I suspect a trip round a track as a passenger would be enlightening!It's nice to be in the correct gear when the car moves out the way and I accelerate away in the correct gear while the car behind fumbles with the clutch.
As for wear, I changed out a clutch in a car I've driven like this for ten years. The clutch was changed because the pressure plate strap had failed and was flailing inside the bell housing. The clutch friction disk was barely half worn, at 150,000 miles.
HustleRussell said:
Same. Since I'm not really into the IAM thang I'm not trying to stop myself doing it, often my sense of mechanical sympathy stops me from making blatently unnecessary shifts but I still like to go down the gearbox at times.
I believe heel & toe basically has no place on the public road, however as I happen to drive older cars in which H & T is possible and having learned how to do it I do use it, albeit for 'fun' rather than any supposed improvement in progress. This habit immediately goes out of the window the first time I try to do it in a modern car, with laggy drive-by-wire throttle, overly sensitive brakes which override the throttle on application, pedals so far apart you could fit another pedal in between them, and sound and vibration insulation so effective that you can't feel how many revs you're at anyway.
It's the mechanical sympathy element which made me ask the question, I don't mind working my car hard (especially with cheap petrol!) but want to avoid doing clown like things that would make a mechanic wince (or rub hands together with glee depending on perspective).I believe heel & toe basically has no place on the public road, however as I happen to drive older cars in which H & T is possible and having learned how to do it I do use it, albeit for 'fun' rather than any supposed improvement in progress. This habit immediately goes out of the window the first time I try to do it in a modern car, with laggy drive-by-wire throttle, overly sensitive brakes which override the throttle on application, pedals so far apart you could fit another pedal in between them, and sound and vibration insulation so effective that you can't feel how many revs you're at anyway.
I drive reasonably sedately anyway, a B road blast is for the twisties rather than flat out speed for me. I used to drive terribly in terms of risk / speed but getting older (and having kids) I am unable to override the, "are you sure" instinct!
Reg Local said:
A couple of things to bear in mind if you're using gears to slow instead of brakes:
1. (As someone has already mentioned) you won't be showing brake lights to the vehicles behind, who may not be looking in the same place as you and may not appreciate that you're slowing down.
2. You'll only be slowing the driven wheels, so unless you're in a car with permanent four-wheel drive, you'll only have two wheels and tyres doing the slowing for you.
In addition, unless you're covering the brake pedal with your foot whilst slowing, there will be a small additional delay if the situation changes and you find yourself needing some brakes.
Best advice when slowing for a hazard is to brake, rather than use the gears. If you want to change down whilst you're braking, fine. You won't pass an advanced driving test with this technique, but if it works for you, then carry on.
Point #2 had never occurred to me and it is the nail in the coffin for my current technique. I'll persevere with unlearning the change down method and stick to using the brakes. Thanks, especially as I want to do my advanced test next year.1. (As someone has already mentioned) you won't be showing brake lights to the vehicles behind, who may not be looking in the same place as you and may not appreciate that you're slowing down.
2. You'll only be slowing the driven wheels, so unless you're in a car with permanent four-wheel drive, you'll only have two wheels and tyres doing the slowing for you.
In addition, unless you're covering the brake pedal with your foot whilst slowing, there will be a small additional delay if the situation changes and you find yourself needing some brakes.
Best advice when slowing for a hazard is to brake, rather than use the gears. If you want to change down whilst you're braking, fine. You won't pass an advanced driving test with this technique, but if it works for you, then carry on.
Are tour responsible for the art of gear change post or is my memory playing tricks?
Reg Local said:
SoupAnxiety said:
Are tour responsible for the art of gear change post or is my memory playing tricks?
This one?http://www.pistonheads.com/gassing/topic.asp?t=361...
Yes, that's one of mine - a recent change in username might have thrown you. If you click through my username to my profile you might find some additional stuff which may interest you if you're looking at taking extra training.
Matthen said:
Does it matter how many wheels are doing the slowing in the describe scenario? The "braking" effect will be so minimal that you are unlikely to unbalance the car?
For a gradual reduction in speed on a good, dry surface? Probably not, no.But the OP stated that they were slowing with the gears habitually, and it's the habit, rather than the specific scenario which can be the problem. 99 times out of 100, slowing with the gears will work just fine - as would slowing with the handbrake, which would give a similar braking effect to slowing with the gears in a RWD car.
But then comes that 100th occasion, where the road is a bit slippery and there's a bit of a corner and the driver is a bit clumsy with their rev-matching, and...
You can write the next part yourself.
Just because something doesn't usually result in an accident doesn't mean it's good practice. Driving too close, for example, doesn't usually result in an accident, but it's not good practice.
Advice noted on slowing with the gears too.
watchnut - I've noticed people who dip the clutch incredibly early and coast. Or people who dip the clutch and change into every gear on the way down, but never lift the clutch!
The irony is in trying to change my down-through-the-gears habit I'm dipping the clutch (to work my way down) and thinking "I'm trying not to do that" and then coasting!
I'm nowhere near your braking record but I do leave a big gap and try to avoid braking where possible, using engine braking to slow me down. It's a more relaxing drive and as you said the time difference in arrival is minimal. I was instinctively changing down into each gear when approaching a junction, now I'm leaving it in the original gear as long as possible and using engine braking that way (one gear) then selecting the lower forward gear. It is easier and saves a lot of faffing, I just need to work at overriding muscle memory!
The irony is in trying to change my down-through-the-gears habit I'm dipping the clutch (to work my way down) and thinking "I'm trying not to do that" and then coasting!
I'm nowhere near your braking record but I do leave a big gap and try to avoid braking where possible, using engine braking to slow me down. It's a more relaxing drive and as you said the time difference in arrival is minimal. I was instinctively changing down into each gear when approaching a junction, now I'm leaving it in the original gear as long as possible and using engine braking that way (one gear) then selecting the lower forward gear. It is easier and saves a lot of faffing, I just need to work at overriding muscle memory!
Johnniem said:
The only likely damage to a clutch would be if the driver used clutch drag (changing down and lifting the clutch to brake) rather than engine braking which means lifting the revs to match engine speed then lifting the accelerator peddle to slow down. You'd be surprised how many drivers believe they are using engine braking when in fact they are using clutch drag. Clutch drag is bad. Don't do it.
I was guilty of this until starting this topic. Clutch drag was "advanced" engine braking to me (!), I now know otherwise. Operate the clutch at the same speed and all braking should be brakes and the engine RPM dropping with the accelerator off. I know loads of people who are guilty of clutch drag and as it's so subtle the mechanical problems are not obvious (such as snatching the clutch or grinding gears which are immediately known for being bad).I've noticed that when selecting the gear to use after a roundabout with a clear road ahead I'm coming off the accelerator, dipping the clutch and easing it up very slowly with no accelerator input to rev match. I'm using the clutch to rev match. I've noticed the bad habit as at higher speed down changes I'm rev matching with the accelerator. Am I right in thinking it is naughty to do this and I'm substituting good rev matching for clutch wear?
Reg Local said:
Sounds like you're lifting off the accelerator completely when you're changing up and allowing the revs to drop to idle speed whilst you're changing gear?
Rather than lifting off completely, you should release the accelerator - but don't lift off it completely. Keep a little pressure on the pedal so that the revs just drop to roughly the correct speed for the next gear. No need to ne excessively slow in releasing the clutch - in fact, if you've matched the revs correctly, the timing of the clutch release isn't really very important (although you should never sidestep - or jump off - the clutch).
There may or may not be a video out there on a popular video-sharing site which demonstrates this. I'd post a link, but the Obergruppenmods get a bit nippy if I do.
I'm trying to rev match when going up, I find this relatively straightforward but the increase in revs in neutral for going down is a bit clunky. What about when changing down? Is it always necessary to increase and hold the revs whilst in neutral on a down change or is it acceptable to just ease the clutch up slowly to match the revs? I've noticed when slowing to turn into the street where I live I'm braking, then (whilst braking) changing from third to second so I'm not rev matching but feathering the clutch up to compensate. Not sure if changing whilst braking is a no no.Rather than lifting off completely, you should release the accelerator - but don't lift off it completely. Keep a little pressure on the pedal so that the revs just drop to roughly the correct speed for the next gear. No need to ne excessively slow in releasing the clutch - in fact, if you've matched the revs correctly, the timing of the clutch release isn't really very important (although you should never sidestep - or jump off - the clutch).
There may or may not be a video out there on a popular video-sharing site which demonstrates this. I'd post a link, but the Obergruppenmods get a bit nippy if I do.
CABC said:
This is the advanced thread though, i think the argument is that you should change down earlier, keeping it smooth but have the 'correct' lower gear so that you have full control of the car, ie accelerate if needed (unlikley in your scenario i agree) or have some engine braking should your brakes fail (which is true). The theory is to be always in control even if it means big blips, high revs etc when you could spend a lifetime never encountering the emergency scenario.
Reading this and the earlier posts I get the idea behind the theory. In some situations, such as the hill with a bend at the bottom, I'm incorporating my gear changes into a manoeuvre. I'll try to change early and avoid using the clutch as a brake.Johnniem said:
The effectiveness of engine braking is obviously proportional to the size and torquiness (sorry!) of the engine. In my former car (TVR Chimaera 450) the torque was incredible and was there from very very low revs, hence I was able to move behind traffic going down very steep hills without use of the brakes at all. Just engage first or second and take foot off accelerator entirely (or use revs to suit). With the current car, Cayman, there is a lot less torque at low revs so the engine braking for the scenario above is less useful but the idea would be to just change down to the lower gear earlier and adjust revs to suit conditions (still using engine braking - rather than clutch drag). This could still be useful in a car with less torque or power but to less effect, if that makes sense?
On my commute home tonight I tried selecting gears earlier and it did feel better arriving at a slow corner (e.g. 90 degree bend into residential area) in the correct gear. I'm already naturally doing it for roundabouts, selecting the gear on approach, I'm not sure why I'm treating junctions differently.Another itch I've got is pulling out of a T junction from a stop. You're in first gear, at the moment I'm changing into second as I pull out and turn left (resulting in one hand on the wheel and a mediocre gear change. I'm being critical of my driving as I've signed up with IAM and will have my first local meeting soon! I'm guessing correct procedure is to stay in first as you turn and when straight change up.
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