tkdbrusco
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D mode is better than B mode? What gives?

Tue May 26, 2015 9:16 am

So I've started to drive my MY15 in D mode more frequently than B mode. I was always under the impression that B+Eco was the best for range and efficiency, but it seems like that's not the case.

My average efficiency in B+Eco was 4.7mi/kwh and my average efficiency in D+Eco was 4.9mi/kwh. I've been driving a nearly identical commute in D+Eco for 1000 miles, so I would assume that these numbers are pretty accurate and would indicate roughly a 4% benefit overall? My GOM readings have also improved, not that this is any real measure.

Here's what I'm thinking, D mode doesn't decelerate as aggressively and thus allows you to coast further. If you feather the throttle, you can actually coast in D mode with one green dot showing. Whereas if I use B mode, it decelerates so aggressively that I often have to use the throttle to speed up more frequently. I've also noticed that there's a very slight bit of added resistance when driving in B mode. If anyone wants to try this out, just drive at a standard speed in B mode, say 45mph and then shift into D mode. What I feel is perhaps a very slight gain in forward momentum, perhaps equivalent to 1-2 mph. Does anyone else notice this? Is this a deficiently of B mode, or is my car broken? What about any damage to the battery for the large amount of regen in B mode (equivalent to QC speeds?)

Lately I'm only using B mode if I know I'll be coming to a stop up ahead and can use the more aggressive regen, or if I'm going down a very steep hill.
2015 Leaf S w/QC Package. San Jose, CA
www.theevconsultant.com

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DuncanCunningham
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Re: D mode is better than B mode? What gives?

Tue May 26, 2015 9:28 am

I'm no expert on this newer Eco+B mode since my wife has the 2015 and I have a 2012. When I have driven it, I guess you drive more with the throttle, all the time. When you want less regen braking, you keep your foot on the throttle, just less than you would with full on regen braking. My 2012 has a nice screen that shows me a pie chart scale of power out and power in. I usually refer to that when I want to see if I can coast (foot still on the throttle) but not putting energy into the motor and then release it further to start pulling energy back and slow down the car before having to use the brake pedal to ask for more regen before the brakes really do kick in.

Eco mode in the 2012 pulls in twice as much regen off throttle (no brake) than the normal D mode does, I like how the 2012 eco runs. My wife never uses the B-mode as it harder to master unless she's going down a long slope that would otherwise need some braking to maintain a safe speed.

Practice is the journey to perfection.. which is always out of reach. Enjoy the journey though.
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2015 Leaf S (leased until May 2018, Bought out in Jan 2017)
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LightningLeaf
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Re: D mode is better than B mode? What gives?

Tue May 26, 2015 9:28 am

I have similar experience like yours

I think B or D mode controls amount of regen (braking) and Echo mode controls amount of acceleration

So with B, D, B+Echo and D+Echo, we have 4 modes of combination for driving.

B - Max. acceleration, Max. Regen.
D - Max. acceleration, Min. Regen.
B+Echo - Min. acceleration, Max Regen.
D+Echo - Min. acceleration, Min. Regen.

This is from my own experience.
2015 S Brilliant Silver with Charging Package. 36 months lease.
Previous Car:2000 Lexus RX300 at 198,000 miles. Only 20 mpg
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davewill
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Re: D mode is better than B mode? What gives?

Tue May 26, 2015 11:09 am

It's all on how you drive it. By definition, regen doesn't recapture but a fraction of the energy used to accelerate the car. If you use D mode, but keep the acceleration under control, and use D mode to do more coasting and use a light foot on the brake pedal so that you mostly regen to stop, then I think you can beat the scenario where someone uses B+ECO to do a lot of extra regen. If on the other hand, the guy using D mode ends up doing a lot of hard braking, he'll do much worse than the B+ECO.
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NeilBlanchard
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Re: D mode is better than B mode? What gives?

Wed May 27, 2015 9:47 am

I have seen my dash display as high as 6.1 miles / kWh after a round trip commute, and I drive in D and shift into neutral as often as possible; using regen only when I have to slow down.

The Leaf coasts really well, and I have the stock tires at 45PSI. My best measured charge (using my Juicebox Premium) is just under 207Wh/mile. I think that is very good, and I am driving at normal speeds; though not often on the highway.

Nfuzzy
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Re: D mode is better than B mode? What gives?

Sat May 30, 2015 9:43 pm

I drive in B mode all the time. No ECO unless it is in winter to limit heater power. It's all about modulating the accelerator to keep it near the neutral bubble as often as possible. Then I still have the full regen available at a moments notice, no shifting required. My normal commute is in heavy traffic with lights, hills, and 55-60mph speed limit. I average around 5.2 mi/kWh in good weather.
2015 Leaf S with QC, purchased July '14
35000mi as of August-17, 92% SOH
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freemywrld
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Re: D mode is better than B mode? What gives?

Fri Jun 05, 2015 3:28 pm

Hi all, I'm brand new - just got my pre-owned LEAF SV (+QC and premium package) on Monday. I've noticed more than one person mention coasting downhill in neutral, but tried that the other night and mine does not got into neutral while the power is on. I was only able to get it to neutral while the main power was off (would toggle between N and P only). Once the car was booted up and ready to drive, the only options were R, D, and B, no neutral. Is that normal for my MY or am I missing something?

Cheers,
Wendy
2013 LEAF SV, fully loaded.

Bob
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Re: D mode is better than B mode? What gives?

Fri Jun 05, 2015 6:11 pm

Wendy,

To put my 2013 Leaf into neutral, I hold the "puck" to the left center for approximately 1 second. It won't go into neutral on a short pop left. It has to be held there.

If that doesn't work, perhaps something is wrong with your Leaf.

Bob

tkdbrusco
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Re: D mode is better than B mode? What gives?

Sat Jun 06, 2015 5:11 pm

You can also put it into R while driving and it will be forced into N. It beeps when you do this, but I don't think it hurts anything. I won't do it on a regular basis though.
2015 Leaf S w/QC Package. San Jose, CA
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DarthPuppy
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Re: D mode is better than B mode? What gives?

Sat Jun 06, 2015 9:41 pm

Interesting observation. I think a lot matters based on driving style as the two modes seem to me to require different handling to be efficient. If you're practiced on efficient driving in D and switch to B and don't change you driving style, I can see how you would get worse performance as these seem to require different feathering of the pedal.

From my experience, my efficiency went up when I switched to exclusively B mode. But you pose a good question.

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