.

[jc2012]

.

[MrToad]

I'll agree that 'wearing out the gearbox' has always seemed like a BS reason, and I always cringe when I hear it given as the only reason for braking before changing down.

Apart from some very specific circumstances, uneccesary gearchanges just distract from where the attention should be - i.e. when can I safely get back on the gas and which gear is most appropriate at that point?

[martine]

Using the gears to slow is just so hard work as well...all those: hand off wheel, clutch down, select new gear, clutch up with a little accelerator to rev-match, hand back...and for what advantage?

Don't know about wearing the gearbox but how about clutch release/thrust bearing?

A go-down-through-the-gears-no-matter-what driver must be doing hundreds of more gear changes in a journey than most people here.

[jont]

If you take intermediate gears, it also spoils the flow, and as a passenger you can get nodding dog syndrome, particularly if the driver isn't smooth.

[Horse]

If you take intermediate gears, it also spoils the flow, and as a passenger you can get nodding dog syndrome, particularly if the driver isn't smooth.

Different issues; a driver who isn't applying the brakes smoothly (and releasing them, for that matter) is likely to be chucking his passengers about like a dinghy in a gale.

However: In my 1.7TD Astra I can slow the engine to about 1k revs in top before declutching to change down. If I try that in the works pool car it'll stall as soon as I declutch.

[jont]

If you take intermediate gears, it also spoils the flow, and as a passenger you can get nodding dog syndrome, particularly if the driver isn't smooth.

Different issues; a driver who isn't applying the brakes smoothly (and releasing them, for that matter) is likely to be chucking his passengers about like a dinghy in a gale.

Even if they are smooth, it's brakes on-brakes off, change gear, brakes on..... brakes-off, change gear etc.

[GJD]

I'm sure we're all familar with the concept of using the brakes to slow down, then making one gear change to suit our new speed. This differs from the old fashioned philosophy of changing down through the gears to aid decceleration.

One of the reasons for this that I've been taught is that it's more economical to wear out and replace brake pads that your gearbox. However, is this a valid reason? I've hardly had an annual service where I've not had to replace either a pair of pads or brake disks, but I've never had to replace a gearbox!

I've heard it as the clutch rather than the gearbox. But either way, I'm not convinced either.

Is this really a valid reason for not changing down through the gears, or are there better justifications, such as not taking your hands off the wheel so frequently?

I think there are better justifications. You've mentioned one. mefoster has mentioned distributing the braking across all the wheels rather than just the driven wheels. If you need to brake and to change gear, you may do each better if you do them separately - concentrating on one thing at a time - than if you do them both simultaneously. If you interleave braking and gearchanging then the outcome is unlikely to be as smooth as you could achieve with a single braking phase. If your right foot is on the brake when you change down, how do you rev match?

[martine]

However: In my 1.7TD Astra I can slow the engine to about 1k revs in top before declutching to change down. If I try that in the works pool car it'll stall as soon as I declutch.

That's interesting...why's that?

[martine]

...If your right foot is on the brake when you change down, how do you rev match?

Heel and Toe obviously... (no I can't do that)

[jcochrane]

Think about how many and which wheels are doing the work when you use the gearbox to slow down rather than the brakes?

Beat me to it . the other point I would add is that using the brake allows for fine modulation to more accurately and smoothly adjust the speed of the car.

[Kevin]

Is this really a valid reason for not changing down through the gears, or are there better justifications, such as not taking your hands off the wheel so frequently?

The only authoritative explanation that I know of as to why gears and not the brakes were once used to slow down is the following:

'Not on the Gears

The fallacy that it is right and good and clever and safe driving to slow on the gears dates back to the days of cable brakes, which frequently did not give even braking on both sides of the car. Because of this drivers developed the technique of changing down to slow down, especially on slippery roads. This gave less effective but even braking on the rear wheels. Nowadays brakes are perfectly balanced so that the problems does not arise, which makes the old solution unnecessary.'

Miles, J., 1977. Expert Driving the Police Way. New Ed. London: Peter Davies Ltd.

[Horse]

If you take intermediate gears, it also spoils the flow, and as a passenger you can get nodding dog syndrome, particularly if the driver isn't smooth.

Different issues; a driver who isn't applying the brakes smoothly (and releasing them, for that matter) is likely to be chucking his passengers about like a dinghy in a gale.

Even if they are smooth, it's brakes on-brakes off, change gear, brakes on..... brakes-off, change gear etc.

So for the later-model Astra example I posted, what am I supposed to do?

[GJD]

However: In my 1.7TD Astra I can slow the engine to about 1k revs in top before declutching to change down. If I try that in the works pool car it'll stall as soon as I declutch.

So for the later-model Astra example I posted, what am I supposed to do?

Not quite sure what the problem is. Is the later model Astra the works pool car?

If the problem is that when you wait until the revs are down to 1000 before declutching the car immediately stalls (is that a fault with the car?) then what happens if you don't wait so long before declutching?

[7db]

So apart from maintenance, there's balance of the vehicle, use of all four wheels, ability to stop (not just slow), signalling to vehicle behind through brake lights, ability to trigger ABS and any other wizardry, ability to modulate braking accurately, ability to change gear as well as slow down, ability to make multiple blippy rev changes through heel-n-toe whilst entering the roundabout which is - I admit - more in the fun department than purely practical.

But apart from that - what have the Romans ever done for us?

[Horse]

However: In my 1.7TD Astra I can slow the engine to about 1k revs in top before declutching to change down. If I try that in the works pool car it'll stall as soon as I declutch.

So for the later-model Astra example I posted, what am I supposed to do?

Not quite sure what the problem is.

I can't brake brake brake . . . then select a gear.

Is the later model Astra the works pool car?

Yup

If the problem is that when you wait until the revs are down to 1000 before declutching the car immediately stalls (is that a fault with the car?) then what happens if you don't wait so long before declutching?

I upset JonT