Agreed that shifting into neutral to slow down makes no sense. Puts all the effort on the brakes, instead of letting engine compression help. Slowing down in gear lets the engine help, and the brakes have an easier job. No wear is placed on the drivetrain, because the clutch and gears remain engaged. no rubbing, no slipping.
Now in regards to actually downshifting… Downshifting to slow down only puts substantial extra wear on the clutch if you do it wrong, which I see a lot of manual drivers do (at least in this country.) Putting the clutch in, shifting to a lower gear and releasing the clutch without any throttle input forces the transmission to speed up the engine via the clutch plate. That means rubbing, and therefore wear. The car decelerates rapidly for a second so it feels really efffective. And it is really effective, but at the expense of extra wear.
The proper method is to “blip” the throttle during the downshift, so that the engine speed is increased to where it needs to be in the lower gear. Then, the clutch is released with the engine speed already correct, and it engages as smooth as butter. The wear is no worse than a smooth upshift (effectively nil), and the extra engine compression still helps slow down better. Of course, to do this while braking requires a little heel-and-toe work to actuate the brake and gas pedals simultaneously. A lot of people aren’t comfortable with that, but it’s not so bad.
Exactly, I’d say the braking combined with proper downshifting is the best of both worlds. If you can’t do the proper engine & transmission speed matching, I’d still say you should stay in gear while braking until the engine starts to labor (you start feeling vibrations.) Then push the clutch and brake.
Well your foot would normally be on the brake, so the former isn’t an issue. As for the latter, I have heard this reasoning before as an argument for leaving the car in gear as opposed to neutral. The argument seems to be that you might get hit from behind, and your foot might slip off the brake, and you might be pushed into the intersection and another car might hit you. Unless I can see some data that shows I’m actually statistically safer by doing either of these things, I’m filing this under statistically insignificant. Setting your parking brake isn’t doing anything; it’s only theoretically protecting against one very specific scenario that seems rather unlikely.
I agree, but your shift to 4th seems superfluous. Why not just slow down until you’re at the correct speed to make the turn, then shift directly into the appropriate gear? Why do you need any intermediate gears? It’s not necessary to go down through all the gears to get from 5th to 2nd. The reason you go through all the gears on the way up is so you don’t labor the engine. When you’re slowing down, that’s not an issue.
If you downshift so soon that the engine is overreving, then yes, you are doing more damage than, good. But just slowing down with the car in the appropriate gear helps slow down without any unnecessary damage. The positive aspect is always being in the correct gear to accelerate if necessary. That doesn’t mean just in an emergency, but if the light you are approaching turns green. If you are doing 60 and slow down in neutral to 20 and the light turns green, which gear do you put it in? 2nd or 3rd? If you put it in too high a gear, the engine will bog. If you put it in too low a gear the engine will over rev, and you risk skidding the rear wheels.
I learned to drive a manual transmission on a motorcycle, and on a bike you never coast in neutral.
Why couldn’t you just put it in gear at such time as you need to? I guess I’m not understanding this need to be in gear “just in case”. It takes but a second to put the car in gear.
The gear you select for a given speed should be whatever gives you the correct engine RPM at that speed. That decision should be independent of whether you arrived at that speed decelerating in neutral or in gear.
The best way to downshift is to double-clutch so that you match revs. I always wince when I see someone hard-shift the transmission into a lower gear and make the engine wind up when the clutch is released. That can’t be good for the drive-train.
I’m doing 65 coming to a red light. I brake, leaving it in 5th gear. I slow to 30. But then the light turns green. So at that point, I change from 5th gear to 3rd gear and continue through the light. There was no need for me to ever be in 4th gear. Nor did I need to be in 3rd gear until I saw that the light had changed. If the light stays red, I simply continue slowing down, still in 5th gear, and at some point before the engine starts lugging, put it in neutral and slow to a stop. I don’t need any other gears, and I’m just putting wear on the drive-train components for no good reason if I keep shifting gears.
Fancy me riding motorbikes since 1979 and not knowing that. As for the car, obviously I keep an eye on the mirror - who wouldn’t? - but I still don’t keep my foot on the brake once it’s clear the guy behind me has stopped. (At our local level crossing, where there’s a bend shortly before the gates and traffic can’t see that the crossing is closed, I make sure to keep my brake lights lit until there is someone stopped behind me, for exactly this reason.)
This whole “wear on the drive train” thing is negligible as long as you’re not engine-braking more aggressively than you normally accelerate, nor is the compression stressing the engine gaskets any more than accelerating would be - less, if your fuel injection cuts out on the overrun.
Nobody’s saying it’s going to destroy your car immediately. The point is that any wear will shorten the life of the component. So if you’re doing something that causes wear, as opposed to not doing that thing, then you are shortening the life of the operative part. Even if it’s equivalent to so-called “normal” wear, it’s still wear. Parts wear out even under “normal” conditions.
“Inconveniencing the driver behind you with your brake lights?” Did you make this up? I have never thought this an inconvenience, nor heard anyone allude to it in any way. Rather, it’s much more helpful to drivers behind to KNOW you’re stopped (or stopping) by seeing your brake lights, rather than having to wonder if you’re moving or starting to move.
Then what I said doesn’t apply. I’ll occasionally pull the parking brake or even put it in park (in an automatic) if someone has already stopped behind me and I expect to be stopped a little while. I’d just hate for someone to do it with people coming up from behind.
I’ve found that using engine breaking during icy conditions can lead to sliding. I downshifted once on an icy road and found my front wheels sliding because the engine breaking os much more strong than the finesse allowed by normal brakes. This is only with front wheel drive of course.