Slowing down in a manual car....

Factual Questions
1

This is Christophers wife and I would like to try to settle a “discussion” Christopher and I have been having.

Long story short I was gifted a manual sports car and taught to drive a stick shift in a day. I was then left to my own devices with the car since my husband and I were living across country at the time. This was about 2 months ago and since then I have become reasonably competent at driving a stick shift… or so I thought. From discussions with friends, and tips from the internet I had come to the conclusion that slowing down (traffic light or exiting freeway etc.) is best effected by downshifting. However, Christopher disagrees and has told me it is better to put the car in neutral and coast/use break to come to a stop. Clearly both methods have the same outcome however, is one method preferrable to the other and why?

2

Cecil says…

3

Use the brakes until you are fairly well slowed down, then shift into 1st or 2nd just before you stop on the chance that you have to maneuver, then put the clutch in all the way.

Brakes are cheaper then clutches or transmissions.

ETA: or listen to Tom and Ray

4

Like Cecil suggests (or like he says mechanics suggest), I leave mine in gear until the engine speed is at idle, and then put it in neutral. Doing that, I don’t even have to use the clutch as there is no torque on the transmission. If you’re going to downshift though, I suggest rev matching or even double clutching. The former saves wear on the clutch plate. The latter also saves wear on the synchronizers.

5

Word for word, this is what a friend of mine said after his downshifting habit cost him three clutch jobs in as many years.

6

Don’t put the car in neutral. Leave it in top gear, I shift into fourth if I’m in fifth in a 5-speed, let it slow down using brakes as needed. It’s OK to shift to a lower gear when you are going slow enough but I don’t do it.

When I’m stopped at then stop sign, then I put the car in neutral and let up on the clutch. This eases the wear and tear on the clutch release bearing and on the thrust bearings in the engine crankshaft. But that’s just me acting on the advice of an engine rebuilder.

7

Cecil is on the money.

In a modern car, in most driving conditions, you don’t need to downshift when slowing (brakes are cheaper to overhaul than clutches and transmissions). On the other hand, you can use the gears to slow. This is because it’s FUN, and I have no problem with that. If you don’t mind the trade-off of potentially wearing some parts out sooner for greater driving enjoyment, then why not?

There are various schools of thought on the issue, and these threads pop up a lot. The safety nazis would like us all to press the clutch as soon as we start slowing from cruising speed, then using the brake as the sole form of retardation, “dry shift” through the gears as you slow, with the clutch still in. The idea is that if you need to suddenly speed up, you’ll be in the right gear already.

For mine, if I’m doing the mindless commute, I just hit the brake, leave it in whatever gear it was in, and then use the clutch just before the engine starts to lug. If I’m in the mood to enjoy driving, I’ll downshift and use the transmission to help slow the car - but I might skip some of the gears.

8

Over here in Britland where manual is the default, I was taught to change down and never coast. If you need to apply power again for some reason, you will want to be in gear to do it. Always be in the appropriate gear for your speed - no need to downshift aggressively but you can certainly use engine braking. In about 13 years of driving stick, I never needed a clutch changed so anyone who burns three in three years must be driving like a gorilla.

ETA: Checked Cecil’s article. On the one hand, automotive engineers. On the other, my driving instructors and the MOT manual I used to read for entertainment. Downshifting while braking, I mean, not engine braking alone.

9

Speaking of which…I was taught to just brake, leaving the car in whatever gear it’s in, and drop the clutch at the last moment. Once stationary, select first.

10

This is still the standard method taught in the UK today. Moving into first is optional dpending on circumstances - if you are first or second in the queue at the lights, yes move into first. Further back, just move into neutral and release the clutch, you’ll have plenty of time to react to the lights and move into first then. Regardless of being in gear or not, the handbrake should always be applied when the vehicle is at rest, and always before moving into neutral.

I understand the always being in the right gear for the speed argument but frankly think it’s rubbish (or at least a one in a million chance). If you are approaching a red light, especially if there is a queue there already, where are you going to accelerate to exactly?

Despite the above, approaching a light i knock it into neutral (no clutch required) and brake/coast. Mainly just to save effort in my clutch leg but partly cause it saves a bit of fuel* and wear/tear.

*i have an older car, i understand this doesn’t apply to newer cars.

11

There are really two separate questions here, engine braking and coasting. Engine braking versus using the actual brakes is debatable, and has indeed been argued about here before. Coasting, as the OP’s husband suggests, is flat-out wrong. Like other British respondents, I was taught to brake and leave the car in gear longer than you might think, and then declutch at the last moment.

12

Having just passed my driving test yesterday I can at least tell you the official way.

If you can, you try to keep the car rolling, it saves on fuel and its strongly emphasised as part of making driving ‘greener’ - this apparently reduces fuel consumption.

This also has the effect of forcing you to plan much further ahead, you slow down earlier to try maintain some momentum so you have to predict what is going on in front.
This also reduces your use of brakes, which dispose of kinetic enrgy as heat, which is apparently not very green.

You do not use the gears for slowing down, you simply look further ahead and come off the gas sooner.

You are alowed to coast in neutral, but only if you are already applying the brakes, and only if its to roll up to stationary vehicles where you are just making up a gap in a queue of traffic.

You are expected to remain in the highest gear that the car can readily cope with, and when you change gear you are now allowed in the test (you are actually expected to demonstrate it) to change through a couple of gears at a time, say from 4th approaching a turn, slow down and drop into second once you have braked down to the correct speed.

This is known as ‘block changing’, you tend to use it more at stops and traffic lights, where you approach in one gear such as third or fourth, stop and simulatneously go into neutral, then switch either to neutral or the gear to intend to resume moving, usually first, but it could be second on a downhill start.

Using gears to slow down instead of brakes in the UK will be classed as a minor fault, collect enough of these and you fail your test, do it hard and it may be classed as a serious fault and fail you in one go.

13

I agree with Malacandra and others on the “no coasting” rule. Once you start coasting in neutral or a too high gear, you’re basically giving up control of your car, and committing to making a full stop in a straight line. A car in neutral handles about as well as a shopping trolley. 99.99% of the time this is not a problem, but if you skid on ice, you’re screwed ; if a horde of rhinos charges out of a side street, you won’t be able to accelerate away as quickly ; if you need to avoid an unexpected obstacle/pedestrian you won’t be able to maneuver tightly etc. Even if traffic simply speeds up again, you’ll have to fumble around getting back in gear.

Although you’re not going to be struck by lightning because you coast to a stop at traffic lights once in a while, your vehicle control is definitely improved by being in (the right) gear at all times, except when stationary. As for the wear and tear issue, my impression is that that has more to do with excessive clutch-riding, instead of clean changes, but I’d have to defer to the experts on that one.

14

I agree with everything said here, but I also agree with Cecil. Why drive a stick shift in this day and time if you can’t be like a race car driver and play with the shifter? I downshift while stopping, and I know it’s more expensive that way.

15

Skid on ice? How does being in gear help?
Rhinos? :smiley:
Obstacle? How does being in gear allow you to turn tighter exactly?
Traffic speeds up? So what if you don’t keep up?

I just don’t get it at all. Having said that i’m surprised at this:

The highway code still says no

Again, i think it’s bunk. No engine braking - so what if you ain’t on a hill? Steering response - i just don’t get this, can anyone explain? Difficult to select the correct gear - erm, why?:dubious:

16

The counter to that, from a mechanic friend, was: “Yeah, but clutches are built to take it, brakes are not.”

However, that comment was made years ago, so might not apply with more modern brakes.

17

All I can say is that ‘The Highway Code’ does not reflect exactly what the drving instructors and examiners are looking for.

An example, on part of my test route there is a fairly steep downhill over railway bridge. The bridge is narrow and so it has traffic lights to allow the single way traffic through both ways up and down.
I was actually on the test itself, approaching this bridge downhill, the lights were red.

I obviously had to stop behind the last car which happened to edge forwards as the queue shuffled up. I was in neutral with the handbrake on. I also shuffled forward using the footbrake and the slop to roll me up closer, I was not in gear during this time. The movement was so slow that even first gear would have been useless.

This is the correct procedure, the examiner did not give me any points against.

You are not allowed to coast at significant speed or for a significant time, such as a long downhill section of raod but for a few metres in a scenario as I have described there is no other real alternative, unless you happen to drive a diesel.

My proof is my driving licence :slight_smile:

18

Nope, it makes no sense to me. I could WAG that maybe in earlier times people were perhaps in the habit of switching the engine off during long downhill runs, to save fuel, and that in the advent of power-assisted steering and brakes it was deemed necessary to advise against the practice. And maybe that advice has lingered on in the Highway Code, despite now being obsolete?

19

Brakes arn’t designed to slow you down? :confused:
Now, can someone tell me why you would want to leave it in the ‘current’ gear just until the engine is about to start lugging? My understanding is that UPS drivers are taught to do this as well with their trucks. Or are you only supposed to do this if you are reasonably sure you will be coming to a stop? It seems to me that if there’s any chance of not coming to a complete stop it would be silly. Trying to accelarate from 10 mph in 4th gear isn’t going to work.

20

As a WAG it would be down to the front wheels no longer dictating direction of travel by gripping as they are forced to rotate by the engine.
If your coasting the wheels are not being ‘forced’ and the car is travelling via momentum.
So if you were to theorhetically spin the steering wheel full lock you may find you carry on moving forwards while scrubbing your tires against direction of travel.