I would like to ask of those who know their Leaf mechanically.

[lemob]

Let's say I'm coasting at 40 mph at Neutral. Then I switch to D to slow down the car, is this harmful to the car.

I know from gas engines, this is not advisable as it causes some harm to the transmission during the sudden transition. However, please correct if I'm wrong, but in leaf, there is not such thing since the engine braking is all done using magnetic fields and no friction or gears involved. Am I wrong in my understanding?

FYI, I'm not asking for opinions if it's safe or not or why I want to do that. I"m asking for pure mechanical facts.

Thanks.

 

[Deleted member 9549]

Let's say I'm coasting at 40 mph at Neutral. Then I switch to D to slow down the car, is this harmful to the car.

I know from gas engines, this is not advisable as it causes some harm to the transmission during the sudden transition. However, please correct if I'm wrong, but in leaf, there is not such thing since the engine braking is all done using magnetic fields and no friction or gears involved. Am I wrong in my understanding?

FYI, I'm not asking for opinions if it's safe or not or why I want to do that. I"m asking for pure mechanical facts.

Thanks.

No harm.

The LEAF does not have any sort of a traditional transmission. The electric motor is ALWAYS connected to the front wheels via a reduction gear. There is no clutch, there are no choice in gears.

Its all run by computer. Reverse simply means reversing the signals to the motor. Regen means placing a load across the motor to act as a generator. Neutral simply means no load and no supply provided to the motor. It freewheels quite well.

The only mechanical part is placing it in Park. That does actuate a pin to lock the gears in place. But again the computer tries to protect the car and will ignore pressing the Park button if going over some low speed.

 

[derkraut]

What you've described is not harmful. (But, switching from "N" to "D" will not result in much "braking"). The ECO mode will result in significantly more regen braking.

 

[lemob]

Thank you very much for the explanation. The reason I ask is that there is this very long slight about over 1 mile in which if I put the car in neutral, it maintains the speed limit of 40 mph exactly all the way to the end of the road. If I put the car in any other mode, it will not maintain that speed. It only works on this leaf too. With my accord, the neutral is not enough to maintain the speed. The leaf's aerodynamics is probably better in this case.

I didn't realize there is an actual pin in parking. Nice to know.

 

[powersurge]

I understand that you are just interested in the mechanical end, but there is no reason to play with the gears while you are moving. I have changed from d to b at low speeds, but still don't like to do it while moving....

 

[speedski97]

Opinion, if cruise is used , instead of neutral. This should keep the car in float. and not have to select neutral. Check on leaf spy or the energy screen in a sv/sl , and see if it is neutral is power use. It my be breaking the law to select neutral in some states.

 

[dhanson865]

I understand that you are just interested in the mechanical end, but there is no reason to play with the gears while you are moving. I have changed from d to b at low speeds, but still don't like to do it while moving....

I'll change from D to B at 50+ when I'm getting off the interstate and I want to regen down an off ramp. No problem, no reason to avoid it.

I'd have no problem doing it at higher speeds if the speed limit were higher and I had the charge and a reason to go faster.

 

[lemob]

I'm going to try doing the cruise control and leaf spy to see if it does use energy when it tries to go steady at that speed. However, even it is the same, I do find it more cumbersome to set cruise control compared to just pushing the N.

Wouldn't it be ironic if I get into trouble for looking at my phone for leafspy data and the reason is trying to avoid breaking the law of driving in neutral.

 

[LeftieBiker]

Cruise control will use at least slightly more power than coasting in D - that's pretty unavoidable. It's easy to use cruise, however, if you make a habit of turning it on whenever you start the car. That's what I've always done.

 

[DuncanCunningham]

Opinion, if cruise is used , instead of neutral. This should keep the car in float. and not have to select neutral. Check on leaf spy or the energy screen in a sv/sl , and see if it is neutral is power use..

best idea I've seen on this post (so far)

 

[Nubo]

Let's say I'm coasting at 40 mph at Neutral. Then I switch to D to slow down the car, is this harmful to the car.

I know from gas engines, this is not advisable as it causes some harm to the transmission during the sudden transition...

As others have noted, the change in drive mode is simply made by altering the input to the electric motor electronically. No harm. The vehicle's regen is less intense than an ICE vehicle undergoing mild engine braking.

But speaking of engine braking, I disagree with your premise. There are plenty of situations where it is advisable to put a manual transmission car into gear to reduce the vehicles speed. As long as one shifts with care, it isn't any more harmful to a transmission than any of the other shifting that goes on. Of course if you shift into a very low gear from a very high speed, things can get interesting. But the LEAF's regen is mild enough where that sort of thing isn't a concern and since the motor is always engaged via single-speed gear, there is no excessive RPM to worry about.

Mal: "Define 'interesting'"
Wash: " 'Oh God! Oh God! We're all gonna' die!'? "

 

[Deleted member 9549]

I understand that you are just interested in the mechanical end, but there is no reason to play with the gears while you are moving. I have changed from d to b at low speeds, but still don't like to do it while moving....

There are no gears.

 

[Beefjerkie]

To chime in on this, I do use between D and B on the freeways going ~80mph (Utah speed limit) and I switch to B ECO on the off ramp to attempt to get energy back.

About 95% of the time I will be using B with ECO and with my experience with cruise control, just watching the dash, it acts like D mode with no ECO. It just pulses or a constant stream to maintain whatever speed set.

With all of my cars, the LEAF is the most aggressive at staying at that speed.

For example, let's say I set the speed to 60mph.

On my Dodge Dart, it has a 3-5mph buffer up and down on downhills and uphills.

On my Nissan Versa Note, it will stay at 60mph unless it's a downhill, it will let the car go up to 70 or 75 so it seems like it doesnt care if its coasting faster then the set speed.

On the LEAF, downhill or uphill, it still stick to 60mph 99% of the time. Sometimes you may see 59 or 61 for a spilt second before it adjusts to it.


I have not tried to toy around with neutral but I could try it and let you know on it. I don't have LEAFSpy to help with that idea.

EDIT: With neutral, it is a true neutral. No regen and no energy going out. I tested on uphill, downhill and flat road. I think they did really well for the car to be aerodynamic. On the flat road, it went pretty far before losing its first mph, downhill this car wanted to run away, and uphill.. well thats a given that the hill is going to fight back.