Coasting to a stop vs down shifting to a stop in manual transmissions

[aquariuscsm]

I always shift into N and coast/use the brakes to stop. I never use the "engine braking" technique.

 

[Badgerstate]

I'm on a manual transmission enthusiast page on Facebook and holy hell this debate is heated. Basically many members believe if you coast to a stop in Neutral you should go buy an automatic and quit driving a stick immediately......they also say coasting causes more clutch wear. I could be wrong but isn't coasting easier on the clutch because your not slipping it each time you down shift? Many in the group say leaving it in neutral causes constant wear. I can personally drive either way but unless I am having fun I usually just coast to a red light ect. I understand the argument of less vehicle control ect but I was always taught it produces less clutch wear and synchro wear? How do you do it? Is one superior over the other. I personally think both have their place and executed correctly both can be viable options. But yeah what do you guys think?

Coasting causes less wear 'n tear on the vehicle but it will cause you to fail a driver's test. Im personally not a fan of the downshifting method because it puts a lot of strain on the driveline.

 

[eljefino]

I believe engine braking creates a vacuum when the air intake is completely shut off. For idle there's usually an idle control valve. But the ECU can figure out that there's no accelerator and the revs are still reasonably high enough that the vehicle is coasting.

You also typically get a "dashpot" high idle as long as the speed sensor shows some MPH. It settles down when the car stops to idle.

My 2000 saturn knew which gear it was in, and when the clutch was slipping (mid shift) because RPM did not match MPH times any known ratio. Fine, except I slapped a wrong-year transmission in and it didn't run all the smog monitors. The fix was driving 55 MPH in 3rd gear, which remained common between years, for ten seconds at light but not zero throttle.

 

[y_p_w]

I always shift into N and coast/use the brakes to stop. I never use the "engine braking" technique.

I only use it when going downhill.

 

[Kiwi_ME]

I'm lazy and would never bother to downshift when slowing down unless I'm on a long downhill. I'll pop it into N as needed to avoid bogging the engine and mostly always use the clutch to do that.

When you consider how a dry-clutch DSG works, such as VW's two 7-speed models, the mechanical technology is not much different over a manual gearbox. However, while driving, the DSG always has one clutch open, continually loading that grease-lubed throwout bearing. When downshifting it never bothers to double-clutch and on every shift mercilessly slams it into what gear it imagines you might need next. If it miscalculates that preset gear then it tries another without any concerns regarding wear. On a downhill it always downshifts to help slow the car and rev matches on clutch changeover but does not double-clutch the gear shift itself.

The rate of shifting of a DSG is perhaps 10 times more than what any human would ever bother doing yet the gearbox designed service life I understand is 300,000 km with a clutch replacement intended at 200,000 km.

 

[partspro]

A guy that specialized in rebuilding manual transmissions told it to me like this: Brake pads are less expensive than transmissions and clutches.

Sorry, the brake pad thing is not really relevant. REV matching always, been driving sticks in many countries and always down shifted with double clutch, done it 56 years !! couldn't change, muscle memory !! BTW changed one clutch in that entire time, and that was on a car i bought used

 

[ron17571]

It's been a while for a stick shift, but I would pop it into neutral most of the time. Being able to figure what gear to have it in when you want to accelerate is more interesting. Like when you don't come to a complete stop. I did like accelerating and then backing out of it and listening to the exhaust on sports cars. Rowing through the gears or downshifting is more fun when a car has a sweet exhaust system.

 

[ls1mike]

Depends on where I am at and what kind of mood I am in.

Strain on the drivetrain? I think it depends on the car. The WS6 does not care what I do unless I miss a shift.

Plus and I am going to sound like an AS*, but the guys who get big miles out of there clutch are not making enough power
to kill them, certainly have not been to track and have not left the line on a 1.6-1.7 sixty foot times in a manual. You have to drive the thing
in order to wear it out, not just ride in it.

 

[930.engineering]

When you consider how a dry-clutch DSG works, such as VW's two 7-speed models,

Two 7-speed dry-clutch DSG transmissions? There's at least three 7-speed DSG
transmissions used in VW models (DQ200, DQ381, DQ500), but only one of them
with dry clutches.
There are more (longitudinal) 7-speed DSG/PDK/S-Tronic used at Audi, Porsche,
Bentley, Lamborghini and Bugatti, however they also come with oil-bath clutches
exclusively. Different story.

the mechanical technology is not much different over a manual gearbox.

True. That's why their gear oils are also quite similar.

However, while driving, the DSG always has one clutch open, continually loading that grease-lubed throwout bearing.

Not sure on that, however I believe it doesn't put load on the crankshaft at least.

When downshifting it never bothers to double-clutch and on every shift mercilessly slams it into what gear it imagines you might need next. ..... On a downhill it always downshifts to help slow the car and rev matches on clutch changeover but does not double-clutch the gear shift itself.

What DSG are you talking about? DQ200? True double-clutching wouldn't make sense
witha DCT as it would seemless gear changes impossible, even though it would help the
synchros. Remember a DCT also can't get into another gear linked to the same clutch.

If it miscalculates that preset gear then it tries another without any concerns regarding wear.

A computer is miscalculating? Honestly, just use the paddles.

The rate of shifting of a DSG is perhaps 10 times more than what any human would ever bother doing yet the gearbox designed service life I understand is 300,000 km with a clutch replacement intended at 200,000 km.

Ten times more - possibly. If you're talking about the DQ200 I'm not sure it'll last 300 Mm.
As far as I know it isn't offered in NA and that certainly for some reason.
.

 

[y_p_w]

It's been a while for a stick shift, but I would pop it into neutral most of the time. Being able to figure what gear to have it in when you want to accelerate is more interesting. Like when you don't come to a complete stop. I did like accelerating and then backing out of it and listening to the exhaust on sports cars. Rowing through the gears or downshifting is more fun when a car has a sweet exhaust system.

The fun comes from hunting gears without a tach. I borrowed my uncle's Toyota pickup once to haul some stuff, and it was really odd trying to figure out when to shift with just a rectangular speedo.

 

[ZeeOSix]

I'd be interested in what automatic rev matching does though, but even then I'd probably just coast into the stop and shift into neutral.

The rev-matching on the newer Mustangs looks to work pretty slick. I agree on your last sentence, I still wouldn't downshift through the gesrs to slow down even if auto rev-matching was going on. Rev matching would be good for track use or driving on tight twisty roads where shifting all the time.

 

[TiGeo]

 

[MParr]

Downshifting through the gears will cause premature clutch plate wear. When I drove manual transmission vehicles, I always let the engine help slow me down. I would keep it in a high gear and let off the gas until the engine speed fell to 1,000 rpms before selecting a lower gear. Most of the time, I had already reached the stop sign or stop light before the engine reached 1,000 rpms. You save on gas this way. You save your clutch and don’t lug the engine.

 

[PF52]

The fun comes from hunting gears without a tach. I borrowed my uncle's Toyota pickup once to haul some stuff, and it was really odd trying to figure out when to shift with just a rectangular speedo.

The old-timers all learned on cars without a tach...... Of course, they only had three forward gears to pick from, so it was easy to choose the right one.

 

[TiGeo]

The old-timers all learned on cars without a tach...... Of course, they only had three forward gears to pick from, so it was easy to choose the right one.

My '92 Toyota truck didn't have a tach, really not a big deal...you just know when it's time!

 

[Avery4]

Do you guys actually look at the tach to know when to upshift? I just shift by how the engine sounds/feels. On a very quiet vehicle that may not work as well though.

 

[PF52]

My '92 Toyota truck didn't have a tach, really not a big deal...you just know when it's time!

Reminds me of the S-10 pickup I had for a few years, a 5-speed. Like most (all?) S-10s, it didn't have a tach, but when I found out the fully-loaded S-10 Blazers (probably automatics only) were available with a tach, I had to have one! I searched the junkyards for months until I found the gauge cluster and to install it in my truck I had to combine parts from both clusters to make it work. My truck used a vehicle speed sensor, for example, and the Blazer used a speedometer cable. But once I had it working right I was the coolest guy in town for a couple years, with a 5-speed S-10 with tach. Still wasn't fast enough to get out of its own way though....

 

[PF52]

Do you guys actually look at the tach to know when to upshift? I just shift by how the engine sounds/feels.

I go by sound/feel also. I think everyone does, eventually, even those who started out by faithfully following the tach.

 

[sk_pete]

if i compare my xsara 1999 vs 2017 c3lll car, it is bloody obvious the amount of engine braking.
new one is very minimal... so it makes sense to keep in gear. (less hassle)
also new cars overcharge agm battery (15v engine braking); car will then stop using alternator (and will go from battery only) to save some fuel.

fuel cutoff does not happen in small revs engine braking, because that is skid hazard (winter)
on old car i could feel that point. 3000 or so

i experienced many bad situations, where downhill braking immediately would skid, but with engine braking i could safely go down.
or braking into winter corner it was much easier to skid, when in neutral..

 

[CheezWhiz]

there is nothing that people will not argue about. who cares!!! your clutch and brake costs over the course of your lifetime are not going to change significantly regardless of which approach you choose.

besides, the proper way to drive a stick shift is to do 5000 rpm clutch drops and power shift at the redline all the way through the gears. clutch wear from downshifting is not your biggest problem when you drive like this