3 ms·

> You can enable free-roling wheels in the car and push away This was mentioned a little earlier and further down in the comment tree but many thanks to you to

by dinom 3y ago

> You can enable free-roling wheels in the car and push away This was mentioned a little earlier and further down in the comment tree but many thanks to you too for clearing this up.

Reubachi 3y ago
I'm racking my brain on this. Why is this not just called exactly what it is, "Neutral"? I just read about this feature which is advertised purely for car washes, and can be gotten into with a wierd combination of actions or "putting the car into neutral". Is it...not just going into neutral via disconecting a drive shaft?
- giobox 3y ago
  > Is it...not just going into neutral via disconnecting a drive shaft? Conceptually you are correct its like neutral, but almost no EV from any manufacturer has disconnecting drive shafts. Every Tesla model except the original roadster is locked in a single gear transmission that never disconnects - one of the big reasons EV drivetrains can be built so reliable with virtually no maintenance requirements (there is no service items on most EV drivetrains until a quick coolant flush in ~10th year of car's life span). The Model 3/Y just dump the output of the rotor into a permanently locked 9:1 trans. There is no need for a reverse gear either as unlike a gas engine the electric motor can easily rotate in both directions. An electric motor cant "stall" like a gas engine and generally never has to change gear, so there is usually no real benefit to fitting the cost and complexity of clutching driveshafts you typically need when you have a gearbox or gas engine. Someone will correct me if I'm wrong, but to best of my memory the only "mainstream" EV with a gearbox on sale today is the Porche Taycan/Audi E-Tron GT (they are both the same chasis/drivetrain underneath) with its pretty unusual 2-speed setup. I wouldn't be surprised at all if the next generation of that car eliminates the gearbox.
  - colejohnson66 3y ago
    If the drivetrain never disengages, how does “freewheeling mode” (neutral) work? Spinning the wheels manually makes them a generator, and that causes resistance from the magnetic flux (hence regenerative braking). How do cars disable that?
    - anticensor 3y ago
      It disconnects the excitation current.
- dinom 3y ago
  > Is it...not just going into neutral via disconecting a drive shaft? Very good point and although IDK how it's done I completely agree with you regarding the terminology. In other words, I don't see new internal combustion cars renaming neutral to be "car wash mode"... lol. Cars should have neutral. And, if yours does then it should be named as such. Making sure I've got "car was mode" is not what I want to do when I'm in the market for a new car. Nor do I want to start reading through the owners manual should I have to push my car onto the shoulder of the road in an emergency. Perhaps my age and crotchety grumpiness is starting to show.

by dinom 3y ago

> You can enable free-roling wheels in the car and push away This was mentioned a little earlier and further down in the comment tree but many thanks to you too for clearing this up.

Reubachi 3y ago

I'm racking my brain on this. Why is this not just called exactly what it is, "Neutral"? I just read about this feature which is advertised purely for car washes, and can be gotten into with a wierd combination of actions or "putting the car into neutral". Is it...not just going into neutral via disconecting a drive shaft?

giobox 3y ago
> Is it...not just going into neutral via disconnecting a drive shaft? Conceptually you are correct its like neutral, but almost no EV from any manufacturer has disconnecting drive shafts. Every Tesla model except the original roadster is locked in a single gear transmission that never disconnects - one of the big reasons EV drivetrains can be built so reliable with virtually no maintenance requirements (there is no service items on most EV drivetrains until a quick coolant flush in ~10th year of car's life span). The Model 3/Y just dump the output of the rotor into a permanently locked 9:1 trans. There is no need for a reverse gear either as unlike a gas engine the electric motor can easily rotate in both directions. An electric motor cant "stall" like a gas engine and generally never has to change gear, so there is usually no real benefit to fitting the cost and complexity of clutching driveshafts you typically need when you have a gearbox or gas engine. Someone will correct me if I'm wrong, but to best of my memory the only "mainstream" EV with a gearbox on sale today is the Porche Taycan/Audi E-Tron GT (they are both the same chasis/drivetrain underneath) with its pretty unusual 2-speed setup. I wouldn't be surprised at all if the next generation of that car eliminates the gearbox.
- colejohnson66 3y ago
  If the drivetrain never disengages, how does “freewheeling mode” (neutral) work? Spinning the wheels manually makes them a generator, and that causes resistance from the magnetic flux (hence regenerative braking). How do cars disable that?
  - anticensor 3y ago
    It disconnects the excitation current.
dinom 3y ago
> Is it...not just going into neutral via disconecting a drive shaft? Very good point and although IDK how it's done I completely agree with you regarding the terminology. In other words, I don't see new internal combustion cars renaming neutral to be "car wash mode"... lol. Cars should have neutral. And, if yours does then it should be named as such. Making sure I've got "car was mode" is not what I want to do when I'm in the market for a new car. Nor do I want to start reading through the owners manual should I have to push my car onto the shoulder of the road in an emergency. Perhaps my age and crotchety grumpiness is starting to show.