Q: D/B/Eco Modes Q: Shifting while in motion

[foolios]

2013 S
My manual says that there is a B mode but the only forward modes I can seem to shift into is D and Eco. I see a B on the dash at the bottom but I believe that is for the second trip odometer. A and B have mileage.
My guess is B and Eco are one and the same but the manual does mention them both separately so it has me confused.
Also, I have searched to find that shifting can be done to neutral while moving.
Can you shift into any mode while moving? My guess is no.
But if you can, can you accidentally shift into reverse while in forward motion?

Thanks in advance.

 

[TomT]

Above about 5 MPH, selecting Reverse will just give you Neutral. A lot of us use it to quickly select neutral when coasting...

But if you can, can you accidentally shift into reverse while in forward motion?

 

[foolios]

Thank you for providing that information. I ran into a thread about shifting into neutral so that the vehicle coasts.
I'm not sure if they meant while in normal mode or economy mode.
Why would you want to coast? Wouldn't that defeat regeneration via braking?

 

[cwerdna]

2013 S
My manual says that there is a B mode but the only forward modes I can seem to shift into is D and Eco. I see a B on the dash at the bottom but I believe that is for the second trip odometer. A and B have mileage.
My guess is B and Eco are one and the same but the manual does mention them both separately so it has me confused.
Also, I have searched to find that shifting can be done to neutral while moving.
Can you shift into any mode while moving? My guess is no.

You have the '13 S which has no B mode. It's only available on '13+ SV and SL, and IIRC, didn't exist on pre-'13 Leafs.

Eco and B mode are NOT one and the same. I can turn Eco on/off via the button on the steering wheel regardless of whether I'm in D or B.

I usually drive around in B. I almost never use Eco. I don't like the accelerator pedal mapping behavior of Eco.

To partially answer "Can you shift into any mode while moving?", I can shift between D and B while moving. I can turn Eco on/off while moving. I believe I have shifted from D or B into N while moving, just for kicks. I can't see any reason why not. I can try tonight.

You can see at http://www.nissanusa.com/electric-cars/leaf/versions-specs/" onclick="window.open(this.href);return false; (for '14), under Mechanical, "B-mode (regenerative braking drive mode)" is listed at Not Available for the S trim.

These may help:
http://sfbayleafs.org/news/2013/01/2013-nissan-leaf-product-highlights/" onclick="window.open(this.href);return false;
http://sfbayleafs.org/commentary/2013/09/2013-vs-2011-nissan-leaf-whats-new-whats-gone-whats-changed/" onclick="window.open(this.href);return false;

 

[LeftieBiker]

As for defeating regenerative braking by coasting, Regen is only, at best, about 40% effecient at recovering energy. Coasting when possible and safe is more efficient.

 

[TimLee]

Above about 5 MPH, selecting Reverse will just give you Neutral. A lot of us use it to quickly select neutral when coasting...

I think the threshold is more like 7 mph.
Coasting works well when the downgrade you are on is just right for the vehicle speed to remain where you want it while coasting, or slowly increase if driving conditions and speed limits support that.
Be careful using coasting.
I was in slow moving congestion one day and was apparently just below the threshold when I shifted to reverse to coast.
When LEAF goes into reverse it comes to a dangerously abrupt stop that is probably also very bad for the drive train. Probably hard on the single speed transmission.

 

[dgpcolorado]

...Why would you want to coast? Wouldn't that defeat regeneration via braking?

Yes, shifting to neutral does defeat regen braking. As to "why", except at very high speeds (near terminal velocity), coasting is much more efficient than regen. When trying to drive efficiently, using regen has lots of energy losses as the charge is put back into the battery. It is more efficient to keep up one's momentum than to brake. However, if one must brake, then regen braking captures some of that kinetic energy of motion that would otherwise be lost.

There are several downsides to coasting. Since regen is off, if you do brake you need to remember to shift back to D or Eco or you will just be using friction brakes (the same thing happens if you are at "100%" charge: no regen). If going downhill, the LEAF is a fairly heavy and low drag car, so it can accelerate quickly. The first time shifting to neutral when going down a steep slope can feel like going over the top on a roller coaster: the LEAF picks up speed very quickly! That could be a safety or speed limit issue.

In general, for efficient driving one wants to keep a steady speed and anticipate slowing or stops. Approaching a distant stop sign, for example, one might shift to neutral to begin slowing down, using drag (air friction, rolling resistance of tires and drive train). Then, as one nears the stop sign, shift to D to apply a bit of regen braking. As more slowing is needed to come to a full stop, shift to Eco for more regen. Finally, apply brakes to come to a full stop.

Of course this stuff takes practice and for many here at MNL it is way more trouble than it is worth and they consider driving inefficiently ("spirited driving") more fun. However, if you are interested in efficient driving ("hypermiling"), a good place to start is Stoaty's Guide to Energy Efficient Driving of the Leaf. Some of us don't see wasting electricity as being any better than wasting gasoline.

Even if you don't want to be a hypermiler, it is useful to practice the skill so that if you are at the limit of your range you can stretch it a bit and make it to your destination.

FWIW

 

[DaveInAvl]

There are several downsides to coasting. Since regen is off, if you do brake you need to remember to shift back to D or Eco or you will just be using friction brakes (the same thing happens if you are at "100%" charge: no regen). If going downhill, the LEAF is a fairly heavy and low drag car, so it can accelerate quickly. The first time shifting to neutral when going down a steep slope can feel like going over the top on a roller coaster: the LEAF picks up speed very quickly! That could be a safety or speed limit issue.

To address this problem, I wonder if it might be useful to have another cruise control mode available - let me try to describe it:

It would have an upper and lower set point, where motor power would be used as needed to maintain the lower set point. If the car came to a significant downgrade and began to pick up speed, it would be allowed to coast up to the upper set point where regen would be used to keep it from exceeding that speed. Then as the grade lessened and leveled out, the car would coast back down to the lower set point and maintain that speed again.

While this could be done by the driver feathering the throttle, it'd sure be convenient for the CC to take care of it automatically. A mode like this could be used to cruise at 55 on a 65-limit hilly road, allowing coasting up to 65 on the downhills. Maybe it could be called "Cruise@10 Under" or something catchy like that...

 

[LeftieBiker]

The car already does something like that: like most cruise control systems, the Leaf's will allow the car to speed up 1MPH going downhill, and will drop the speed by 1MPH when going uphill. ;-)

 

[BrockWI]

Way back when.... I installed cruise in a car it had a dip switch for 1 or 3 or 5, next to the 5 was "economy mode" I played with it and it was slower to respond on each setting letting you get off your set point. So the 5 would let it slowly drift 2.5 slow or fast before reacting and when it did react it was slower on the throttle, I never understood why this isn't an option nowadays.

 

[LeftieBiker]

Way back when.... I installed cruise in a car it had a dip switch for 1 or 3 or 5, next to the 5 was "economy mode" I played with it and it was slower to respond on each setting letting you get off your set point. So the 5 would let it slowly drift 2.5 slow or fast before reacting and when it did react it was slower on the throttle, I never understood why this isn't an option nowadays.

Especially on cars like the Leaf, Prius, etc.

 

[dgpcolorado]

To address this problem, I wonder if it might be useful to have another cruise control mode available - let me try to describe it:

It would have an upper and lower set point, where motor power would be used as needed to maintain the lower set point. If the car came to a significant downgrade and began to pick up speed, it would be allowed to coast up to the upper set point where regen would be used to keep it from exceeding that speed. Then as the grade lessened and leveled out, the car would coast back down to the lower set point and maintain that speed again.

While this could be done by the driver feathering the throttle, it'd sure be convenient for the CC to take care of it automatically. A mode like this could be used to cruise at 55 on a 65-limit hilly road, allowing coasting up to 65 on the downhills. Maybe it could be called "Cruise@10 Under" or something catchy like that...

While that might be nice to have, the problem is complexity. The LEAF is already too complex and "different" for many ordinary drivers. I've used this analogy before, but recall that in the days of the VCR the majority of them would blink "12:00" because the owners didn't know how to set the clock, much less program them to record. In short: a large number of people are militantly ignorant when it comes to technology and devices. And you want to have a complex, multi-functioned, cruise control? Many LEAF owners can't even be bothered to learn how to set the charging timer, never mind actually read the manual!

So, yes, your suggestion would be lovely for the enthusiasts here at MNL. But, as with many suggestions of improvements to the LEAF systems, it would add complexity to a car that Nissan really needs to keep as simple as possible for wider adoption.

One suggestion wrt cruise: If you normally drive in Eco for improved efficiency and the energy-mapped throttle, it helps a bit to switch to D for cruise (and switch off B mode I would guess, if you have it — I don't) since that will reduce regen braking somewhat when driving on the downhill portions of undulating terrain. D mode allows a slightly wider speed range when using cruise on roads that aren't level, thanks to reduced regen.

 

[BrockWI]

So, yes, your suggestion would be lovely for the enthusiasts here at MNL. But, as with many suggestions of improvements to the LEAF systems, it would add complexity to a car that Nissan really needs to keep as simple as possible for wider adoption.

I totally agree, but I don't understand why they don't "hide" or bury a setting like that in the nav system under some obscure settings tab. I suppose it adds coding and complexity to the system, but I know I would use it, but agree that most wouldn't know or understand. Heck I bet the drive and eco modes confuse people as well. I guess they could map the cruise to be more forgiving in eco mode compared to regular drive mode, maybe they already do? I have an S and the biggest thing I am missing is cruise

 

[dgpcolorado]

...I have an S and the biggest thing I am missing is cruise

At least Nissan appears to have fixed that with the 2015 models. According to the specs released in Canada, the S has a lot of missing features, such as cruise control, added back in. What I want, given where I live, is B mode. But what little regen that I had was drastically reduced by the P3227 software update, to my considerable disappointment.

 

[BrockWI]

Yes I saw that the 15 S's looks like it has cruise. Honestly I didn't think I would miss cruise driving it mostly in town, but yet I do

 

[TomT]

Remember that does not necessarily indicate that the U.S. content will be the same...

At least Nissan appears to have fixed that with the 2015 models. According to the specs released in Canada, the S has a lot of missing features, such as cruise control, added back in.

 

[dgpcolorado]

Remember that does not necessarily indicate that the U.S. content will be the same...

Yes, that's why I stated the source of the info. We don't know for sure yet, as you say.

 

[foolios]

Thanks all for the advice and the link to the efficient driving guide.