Putting the LEAF in "N"

[Jimmydreams]

You can safely go from drive to neutral by throwing the shifter into reverse when traveling at a high enough speed. If you do it at a low speed, you will go into reverse, which I don't reccomend. The car will make two small beeps when doing this.

I have found that coasting in neutral is a great way to travel.

Don't throw it in reverse....just push the joystick to the left into N and hold it there for a few seconds....the car will safely go into neutral at any speed without worry of slamming into reverse at speed X.

 

[thankyouOB]

does coasting in N, which i love to do in my manual ICE, improve mileage over getting regen in ECO (a lot of regen) or D (some regen)?

 

[Jimmydreams]

does coasting in N, which i love to do in my manual ICE, improve mileage over getting regen in ECO (a lot of regen) or D (some regen)?

I think it's a question of energy efficiency; Regen isn't as efficient as the energy it took to make the car move in the first place, so on that scale, on flat ground regen isn't very efficient.

But, when going downhill, regen will 'take' energy from the hill by keeping your speed constant. It's a form of 'free' regen because gravity is generating it. BUT, is is having some regen and a constant speed more efficient than letting gravity bring your speed UP and therefore you hit the flat ground/uphill section with more kinetic energy??? How much energy value is there in increased speed/coasting ability vs the regen attained from speed control going down the same hill??? (someone call Bill Nye, the Science Guy!)

Someone better schooled in physics would have to answer that one.

 

[LEAFfan]

does coasting in N, which i love to do in my manual ICE, improve mileage over getting regen in ECO (a lot of regen) or D (some regen)?

I asked that very same question and I can't remember who answered it, but they said it was better to use 'neutral' (it's easy to use the accelerator and coast...been getting 5.8m/Kwh/8.7 CW) than 'regen' in ECO. This probably belongs in 'tips and tricks', but I've discovered that I can coast a long time using CC by going one mph over what I want, then hit the down cruise button to drop it one...it goes into neutral and stays in neutral on flat ground.

 

[thankyouOB]

does coasting in N, which i love to do in my manual ICE, improve mileage over getting regen in ECO (a lot of regen) or D (some regen)?

I asked that very same question and I can't remember who answered it, but they said it was better to use 'neutral' (it's easy to use the accelerator and coast...been getting 5.8m/Kwh/8.7 CW) than 'regen' in ECO. This probably belongs in 'tips and tricks', but I've discovered that I can coast a long time using CC by going one mph over what I want, then hit the down cruise button to drop it one...it goes into neutral and stays in neutral on flat ground.

are you calling Neutral, the center DOT?
is there some evidence that is the equivalent of selecting neutral on the shifter?

 

[johnr]

I've discovered that I can coast a long time using CC by going one mph over what I want, then hit the down cruise button to drop it one...it goes into neutral and stays in neutral on flat ground.

I'd have to disagree with you there. Cruise simply adjusts power to or regen from to acheive a given speed, in the transition you might get to the equivalent of neutral as it crosses the line, but here's what actually happens: it would regen for a second to slow the speed and then gradually reduce regen and begin applying power to hold that speed. Unless you've found some "easter egg" there's no way I know of to get neutral in CC.

are you calling Neutral, the center DOT?
is there some evidence that is the equivalent of selecting neutral on the shifter?

In the LEAF, neutral is defined as no power going or coming from the motor. So, yes, the center dot. But, just trying to keep it in the center dot by applying light pressure to the accelerator pedal or by using the cruise control is not going to truly get you to neutral, you might be applying a tiny amount of regen or using a tiny amount of power, and you wouldn't know it. To be absolutely certain no power is going to or from the motor, to truly enter neutral mode, you need to select neutral with the "shifter" knob.

You can put the car in neutral, and take it back out of neutral, at any speed. Even with your foot on the accelerator. It doesn't matter. Simply push the selector to the N position and hold it there for a couple seconds. To go back to drive just push to D. It's as easy as can be! If you're in cruise control, you can still slip into neutral in the same way, and then when you return to drive, press the resume button in cruise and it speeds up to continue at the cruise control setpoint. It's fun to alternate between neutral, drive, and eco to maximize range on gradual ups-and-downs.

 

[LEAFfan]

I asked that very same question and I can't remember who answered it, but they said it was better to use 'neutral' (it's easy to use the accelerator and coast...been getting 5.8m/Kwh/8.7 CW) than 'regen' in ECO. This probably belongs in 'tips and tricks', but I've discovered that I can coast a long time using CC by going one mph over what I want, then hit the down cruise button to drop it one...it goes into neutral and stays in neutral on flat ground.

are you calling Neutral, the center DOT?
is there some evidence that is the equivalent of selecting neutral on the shifter?

Yes, when it's in the center dot, no power is being used, so it's the same as putting the shifter into neutral.

 

[johnr]

Yes, when it's in the center dot, no power is being used, so it's the same as putting the shifter into neutral.

Almost, but not quite exactly

 

[gbarry42]

There are even more things to consider. For one, as you hit 70 going downhill, the air resistance is stealing some energy that you might have gotten if you were regenning at 60. This gets complicated with all these variables. I found (in the Prius) that much of this does not make nearly as much difference as just having warm weather. And in the LEAF I've discovered that just keeping the speed down on the freeway makes a lot more difference than whether I'm using the A/C, or ECO vs. drive, etc.

If you don't like the SOC "bars" you are not going to like the "dots", either. Turn on the energy display (the dials with the kW readings) and watch the big one. Comparing to the "dots", I see 5-7 kW "hysteresis", which means you have 10 or 15 kW of uncertainty when the center dot makes you think you're in Neutral.

 

[LEAFfan]

I'd have to disagree with you there. Cruise simply adjusts power to or regen from to acheive a given speed, in the transition you might get to the equivalent of neutral as it crosses the line, but here's what actually happens: it would regen for a second to slow the speed and then gradually reduce regen and begin applying power to hold that speed. Unless you've found some "easter egg" there's no way I know of to get neutral in CC.
But, just trying to keep it in the center dot by applying light pressure to the accelerator pedal or by using the cruise control is not going to truly get you to neutral, you might be applying a tiny amount of regen or using a tiny amount of power, and you wouldn't know it. To be absolutely certain no power is going to or from the motor, to truly enter neutral mode, you need to select neutral with the "shifter" knob.

That's okay to disagree, but it still does it. I've traveled more than a mile using cruise and the power in neutral. How do you think I'm achieving almost 6m/Kwh (car...not CW)? I've already earned the 'Platinum' trophy (regional) for highest m/kwh so I guess I found that elusive 'Easter egg'. If I were using any power or any regen, it would show on the meter I would think.

 

[LEAFfan]

If you don't like the SOC "bars" you are not going to like the "dots", either. Turn on the energy display (the dials with the kW readings) and watch the big one. Comparing to the "dots", I see 5-7 kW "hysteresis", which means you have 10 or 15 kW of uncertainty when the center dot makes you think you're in Neutral.

What do they read when you put the shifter into neutral?

 

[LEAFfan]

Yes, when it's in the center dot, no power is being used, so it's the same as putting the shifter into neutral.

Almost, but not quite exactly

I did what you suggested...looked at the traction motor Kw meter while the dot was in the center and depending on speed, it varied from 1 (25mph)- around 5 (45mph). But I obtained 5.7 m/kwh on the dash. So what did you get on the traction motor power meter when you put the shifter into neutral and at what speeds?

 

[Caracalover]

Yes, when it's in the center dot, no power is being used, so it's the same as putting the shifter into neutral.

Almost, but not quite exactly

I did what you suggested...looked at the traction motor Kw meter while the dot was in the center and depending on speed, it varied from 1 (25mph)- around 5 (45mph). But I obtained 5.7 m/kwh on the dash. So what did you get on the traction motor power meter when you put the shifter into neutral and at what speeds?

When you are in true N, even with your foot on the accelerator, you use no power and regain no power.

A force in motion will remain in motion until an equal and opposite force is ...

So while the drag from wind at 70 might slow you, if you got there by coasting in N (Which you would have to be on a really big hill to get to BTW) you would do better than staying at a slower speed with less drag, since as the wind drag slows you, you would return to lesser drag. Every time you regen as you attempt to maintain speed, you lose kinectic energy, storing only a fraction (Small) of that energy. This is not a perpetual motion machine, so while it is nice to be able to regen some of the energy used, you will never regain all of it. Use regen when you want to slow down, not when you want to keep going.

 

[planet4ever]

Your argument doesn't make sense to me. Let's say I'm at the top of a really big, steep, hill with a flat section below it. I start down at 55 in neutral and speed up to 70. If it weren't for the air resistance I would probably be doing at least 90 by the time I got to the bottom. Once at the bottom the air resistance is going to slow me fairly quickly from 70 to 55. All of the potential energy difference got eaten up in fighting high speed air resistance.

Now I try again, using regen to keep me at 55. This time I build up a nice battery reserve that will last me a while on the level stretch. Certainly I won't be able to recover all of the energy to the battery, maybe not even half of it. But just as certainly I will have lost much less to air resistance.

I'm not saying regen is definitely better, but I don't think your argument shows that coasting is definitely better, either.

Ray

 

[Caracalover]

Your argument doesn't make sense to me. Let's say I'm at the top of a really big, steep, hill with a flat section below it. I start down at 55 in neutral and speed up to 70. If it weren't for the air resistance I would probably be doing at least 90 by the time I got to the bottom. Once at the bottom the air resistance is going to slow me fairly quickly from 70 to 55. All of the potential energy difference got eaten up in fighting high speed air resistance.

Now I try again, using regen to keep me at 55. This time I build up a nice battery reserve that will last me a while on the level stretch. Certainly I won't be able to recover all of the energy to the battery, maybe not even half of it. But just as certainly I will have lost much less to air resistance.

I'm not saying regen is definitely better, but I don't think your argument shows that coasting is definitely better, either.

Ray

Try this - accelerate to any speed on a flat area, throw it in N. see where you stop. Then try the same in ECO, watching how much regen you are "gaining" back, then use that much energy for that length of time to go forward. Try again in D. I think you will find that the N gets you the most distance.

 

[planet4ever]

Try this - accelerate to any speed on a flat area, throw it in N. see where you stop. Then try the same in ECO, watching how much regen you are "gaining" back, then use that much energy for that length of time to go forward. Try again in D. I think you will find that the N gets you the most distance.

I have no argument with that. The issue arises when coasting causes you to accelerate above your normal driving speed. That is when I say there is an unknown (at least to me) tradeoff between regen losses and high speed air resistance losses.

Ray

 

[adric22]

I actually use neutral on my Leaf regularly when going down a long hill. I only do it if the hill isn't steep enough to accelerate the car, otherwise I'd have to use my brakes to slow the car down, which would waste energy.

I assume it probably works similar to neutral in the Prius. Since the Prius also has no traditional transmission and there is no way to disengage the I.C.E. from the wheels, they use an "electronic" neutral. Essentially relays are opened somewhere in the electronic system that prevents any power going to or from the electric motors. Without the electric motors, the engine will just spin freely.

In fact, I have encountered problems in automatic car washes in my Prius before. When put into neutral, the Prius can't even generate electricity even though the engine is running. That is bad news if you are running the air conditioner. It will run your battery down before you get out the other side. And since you can't roll your windows down either, the only thing you can really do is turn the A/C off, maybe leave the vent blowing.

 

[Coffee_Slurry]

I actually use neutral on my Leaf regularly when going down a long hill. I only do it if the hill isn't steep enough to accelerate the car, otherwise I'd have to use my brakes to slow the car down, which would waste energy.

I think if you take some careful measurements and watch the power indicators, you'll find that this isn't improving your range.

 

[Jimmydreams]

I actually use neutral on my Leaf regularly when going down a long hill. I only do it if the hill isn't steep enough to accelerate the car, otherwise I'd have to use my brakes to slow the car down, which would waste energy.

Drop into ECO for a minute to capture regen (and slow down), then back to N for coasting. No touching the brakes, no wasted energy!

 

[gbarry42]

If you don't like the SOC "bars" you are not going to like the "dots", either. Turn on the energy display (the dials with the kW readings) and watch the big one. Comparing to the "dots", I see 5-7 kW "hysteresis", which means you have 10 or 15 kW of uncertainty when the center dot makes you think you're in Neutral.

What do they read when you put the shifter into neutral?

In Neutral, everything is "disconnected" and therefore reads zero (center dot, and no indication on kW gauge). I did this at 20 and at 60. I fully expected this result, but it seemed proper to actually try it first.