bernie82
Posts: 90
Joined: Fri May 25, 2012 8:12 pm
Delivery Date: 20 May 2012
Leaf Number: 019707
Location: sacramento, Ca

Re: Drive option that better incorporates neutral/coasting

Sat Jan 05, 2013 11:39 am

I thought that regen adds power to the battery since the bubbles on the dash show regen. Coasting in neutral merely doesn't use any power. Why then, is coasting in neutral more efficient than regen?
I'm guessing that taking your foot off the gas pedal when you're in drive still puts some drag on the car. Is that correct?
How can you switch into neutral and still maintain a steady speed unless you just do it on down grades?
About how many extra miles of range could an expert neutral switcher glean assuming his range without switching was 80 miles and he was driving on level terrain?

bernie82
Posts: 90
Joined: Fri May 25, 2012 8:12 pm
Delivery Date: 20 May 2012
Leaf Number: 019707
Location: sacramento, Ca

Re: Drive option that better incorporates neutral/coasting

Sat Jan 05, 2013 11:53 am

Why would any Leaf driver concern themselves about extending range unless they were in a situation where they were pushing the range envelope?

User avatar
EVDRIVER
Moderator
Posts: 6753
Joined: Sat Apr 24, 2010 7:51 am

Re: Drive option that better incorporates neutral/coasting

Sat Jan 05, 2013 12:01 pm

I can get the same or better efficiency as those that keep popping into neutral. IMO this is all about your driving skills. Those that need to brake at times will loose regen because they are not in ECO. This is easy to factually prove and I can't believe that people are wasting time and wearing on the their drive selector to do this. Likely there are some in this group of hair splitters that also drive with low pressure in their tires and are holding up traffic from costing too slowly to lights. Too funny.

DaveinOlyWA
Posts: 14800
Joined: Sat Apr 24, 2010 7:43 pm
Delivery Date: 16 Nov 2019
Leaf Number: 319862
Location: Olympia, WA
Contact: Website

Re: Drive option that better incorporates neutral/coasting

Sat Jan 05, 2013 12:08 pm

most of this has probably already been said;

** it might or might not be the same efficiently to "dead band" (driving in gear at zero power use according to energy screen) but facts are , it is A LOT HARDER TO DO. and let me clarify coasting in neutral requires no more effort than shifting into reverse.

now dead banding is not difficult but requires much more than 80% concentration to maintain. nearly always way more work than is necessary. In a typical 5 mile in town trip during heavier traffic i will shift from eco to drive to neutral and every combo there of probably 50 times and have been doing it for a long time. i dont think i will wear anything out by doing this simply because the transition from one mode to the other is still as seamless as it was from day one. if you drive a hybrid, you know what i am talking about. the Prius is a pretty smooth transitioning vehicle but you can still feel it. what you feel is a stress point somewhere in the system. a stress point will eventually fail. The LEAF does not have that feel. now it might still fail, but betting we wont live long enough to see it.

** having a user selected function to automate "neutral" is not going to be an option EVER, so stop talking about it. once again, shift to reverse. the reason is because you want regen about as much as you want reverse. shifting is something that i find EXTREMELY easy to do. the instantaneous decision making process required while driving to determine if regen is applicable or not does not allow me to effectively use it if i need to take additional steps to make it work.

when driving and a light changes to red, i immediately go into neutral if the light is a sufficiently far off distance (usually at least .3-.5 miles) this allows minimal loss of momentum and more importantly more time to evaluate the situation as to whether i can go to drive and regain some charge or leave it in neutral and hope traffic clears fast enough to prevent touching the brakes.

with shorter distances to the light, its either drive or eco. either way, my philosophy is that if i dont touch the brake pedal, i dont have to worry about hitting it so hard that i enable friction braking. heat = inefficiency.

think about a gas car; for every $5 in gas, you are spending a buck to get somewhere, $4 to warm the planet and a lot of that is wasted heat. take your gas car and drive around town at speeds UNDER 40 mph for 15 minutes, then park it in your driveway and touch the brake rotors. do it quickly to reduce the severity of the burn you will get. then try it with your LEAF. dont worry, the rotor will be warm but pleasantly so.


http://www.pluginrecharge.com/2013/01/t ... issan.html" onclick="window.open(this.href);return false;
2011 SL; 44,598 mi, 87% SOH. 2013 S; 44,840 mi, 91% SOH. 2016 S30; 29,413 mi, 99% SOH. 2018 S; 25,185 mi, SOH 92.23%. 2019 S Plus; 10,081 mi, 95.03% SOH
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

edatoakrun
Posts: 5222
Joined: Thu Nov 11, 2010 9:33 am
Delivery Date: 15 May 2011
Leaf Number: 2184
Location: Shasta County, North California

Re: Drive option that better incorporates neutral/coasting

Sat Jan 05, 2013 1:21 pm

Reading this and other threads, I believe the efficiency benefits of "coasting", whether in N or D/ECO, are vastly overestimated by many LEAF drivers.

In almost all driving circumstances at normal driving normal highway speeds (IOW, not while "coasting" at a variable 15 to 30 mph while obstructing traffic, with a sign in your rear window or with your emergency blinkers on) you will maximize your efficiency driving over a given route in a given amount of time by maintaining a more constant speed than is possible if you are "coasting" for a large fraction of your miles driven.

Yes, there is a slight loss of efficiency every time you apply kW to the road, and a larger inefficiency of the energy conversion when you recycle that energy with regen. But if you are varying your speed by a large amount due to your obsession with coasting, you may be reducing your overall efficiency due to the effects of the higher energy loss you are causing by varying your speed.

As I posted on the thread preceding this one:
...On the broader question, I am very skeptical of the claims of advocates of coasting in N as producing significant efficiency gains, as there really is no way to test this theory. Most who advocate the use of N do not seem to acknowledge the efficiency drawbacks inherent in this practice.

Allowing your LEAF's kinetic energy and the road grade to determine your speed, or "coasting", invariably results in varying your speed significantly.

If you want to minimize the energy loss to air resistance to travel any given distance over any given time, maintaining as close to constant speed as conditions permit is optimal. And this of course requires using the accelerator/regen pedal.

I always drive in ECO, and do anticipate my future kW needs to maintain as near-neutral energy use as conditions permit, and avoid the brake pedal whenever I can.

But I also have no qualms about accepting the "inefficient" regen energy from a descent rather, than losing it to friction with the atmosphere, when maintaining my desired speed descending a grade. And I don't worry if I have to apply kW to maintain my desired (safe and efficient) speed in all other road conditions.
http://www.mynissanleaf.com/viewtopic.p ... 0&start=90" onclick="window.open(this.href);return false;
no condition is permanent

N1ghtrider
Posts: 447
Joined: Sat Dec 17, 2011 10:19 pm
Delivery Date: 01 Aug 2013
Leaf Number: 412388
Location: South Florida (Miami/Coral Gables)

Re: Drive option that better incorporates neutral/coasting

Sat Jan 05, 2013 3:30 pm

I have more reported 100-plus miles on a charge (and more 200 Km charges) than any other forum member. All of those were accomplished without shifting into neutral. Now I typicallly shift into N going down a long downhill ramp (until reaching the end when I shift into ECO to get some regen) because I am not an engineer and believed the reports that it was more efficient than staying in ECO, but I am living proof that long range can be attained without doing it.
Roy D. Wasson (N1ghtrider)
Member 100 Mile Club & 200 km Club in 2012 SV & 2013 SL
Board Certified Appellate Attorney
28 W. Flagler St. Suite 600
Miami, FL 33130
(305) 372-5220 ofc
(305) 519-8897 cell
roy@wassonandassociates.com

jlsoaz
Posts: 748
Joined: Sun Jul 08, 2012 12:57 pm
Delivery Date: 10 Oct 2012
Leaf Number: 24218
Location: Southern Arizona, USA

Re: Drive option that better incorporates neutral/coasting

Sat Jan 05, 2013 4:37 pm

N1ghtrider wrote:I have more reported 100-plus miles on a charge (and more 200 Km charges) than any other forum member. All of those were accomplished without shifting into neutral. Now I typicallly shift into N going down a long downhill ramp (until reaching the end when I shift into ECO to get some regen) because I am not an engineer and believed the reports that it was more efficient than staying in ECO, but I am living proof that long range can be attained without doing it.
Hi Nightrider - I don't think the question is whether long range can be achieved without switching into neutral. I think the question is whether even longer range can be achieved by using neutral judiciously since it avoids the wasteful practice of expending energy only to recycle some (but not all) of it.
Former lessee 2012 SL
http://www.pluginamerica.org/surveys/ba ... hp?vid=229
2017-October: bght 2013 Volt
will buy 150+ mile BEV when they become less expensive on used market
opinions expressed are my own

jlsoaz
Posts: 748
Joined: Sun Jul 08, 2012 12:57 pm
Delivery Date: 10 Oct 2012
Leaf Number: 24218
Location: Southern Arizona, USA

Re: Drive option that better incorporates neutral/coasting

Sat Jan 05, 2013 5:04 pm

DaveinOlyWA wrote:most of this has probably already been said;

** it might or might not be the same efficiently to "dead band" (driving in gear at zero power use according to energy screen) but facts are , it is A LOT HARDER TO DO. and let me clarify coasting in neutral requires no more effort than shifting into reverse.
Hi Dave: I agree, as the vehicle is presently set up, exact dead-banding is a lot harder (or impossible over long distances). One of the suggestions that was made in this thread that maybe should get some consideration from Nissan is making it so that the dead band range in the pedal is wider and with boundaries (whereas at present there seem to be none). I'm not sure if this is my favorite suggestion for making neutral easier for those of us who are uncomfortable switching the car out of gear.
DaveinOlyWA wrote: (...)
** having a user selected function to automate "neutral" is not going to be an option EVER, so stop talking about it.
What a nice way to put things. :-)

I respect the thinking and passion you're putting in to driving the vehicle, but my own goal here is to ask if the efficiency gains you and other pioneers are evidently attaining can be made easier for other drivers to attain and, importantly, be counted as mainstream-attainable enough such that they would result in an increase in EPA (and other regulatory bodies overseas) numbers. This would help Nissan in business and would help drivers consider getting into the vehicle. Switching into and out of neutral (whether by switching to R while in forward motion or by holding at N for a couple of seconds) and then switching out of neutral seems a hassle that some won't bother with while a switch or attenuator, or a widened better-defined pedal zone might require less futzing to achieve the same or similar result.
DaveinOlyWA wrote: ....with shorter distances to the light, its either drive or eco. either way, my philosophy is that if i dont touch the brake pedal, i dont have to worry about hitting it so hard that i enable friction braking. heat = inefficiency. ...
I didn't realize that your thinking was so focused on this aspect of avoiding using the brake. We had a separate and I think good-looking suggestion for an indicator that helps us know when we are using the friction brake.
Former lessee 2012 SL
http://www.pluginamerica.org/surveys/ba ... hp?vid=229
2017-October: bght 2013 Volt
will buy 150+ mile BEV when they become less expensive on used market
opinions expressed are my own

jlsoaz
Posts: 748
Joined: Sun Jul 08, 2012 12:57 pm
Delivery Date: 10 Oct 2012
Leaf Number: 24218
Location: Southern Arizona, USA

Re: Drive option that better incorporates neutral/coasting

Sat Jan 05, 2013 5:09 pm

bernie82 wrote:Why would any Leaf driver concern themselves about extending range unless they were in a situation where they were pushing the range envelope?
Hi Bernie -

Virtually all Leaf drivers and potential buyers are concerned with range to some degree. It is a key purchasing and operational consideration for many (if only such as planning out a trip or a day of travel, or figuring out if a hydrocarbon powered vehicle is necessary).
Former lessee 2012 SL
http://www.pluginamerica.org/surveys/ba ... hp?vid=229
2017-October: bght 2013 Volt
will buy 150+ mile BEV when they become less expensive on used market
opinions expressed are my own

jlsoaz
Posts: 748
Joined: Sun Jul 08, 2012 12:57 pm
Delivery Date: 10 Oct 2012
Leaf Number: 24218
Location: Southern Arizona, USA

Re: Drive option that better incorporates neutral/coasting

Sat Jan 05, 2013 5:17 pm

bernie82 wrote:I thought that regen adds power to the battery since the bubbles on the dash show regen. Coasting in neutral merely doesn't use any power. Why then, is coasting in neutral more efficient than regen?
I'm guessing that taking your foot off the gas pedal when you're in drive still puts some drag on the car. Is that correct?
How can you switch into neutral and still maintain a steady speed unless you just do it on down grades?
About how many extra miles of range could an expert neutral switcher glean assuming his range without switching was 80 miles and he was driving on level terrain?
Hi -

I'm not experienced yet in trying to attain higher efficiency with the method of switching in and out of neutral, but to my mind the scientific argument (in my own inadequate words) is that since regen braking is not 100% efficient, then when we are constantly using it, what we are really doing is applying power just to half-efficiently recycle it a few moments later. Recycling is great where necessary, but better to not expend the resource in the first place? My guess is that once there is more empirical data, optimization of range would be based on some combination of neutral switching and judicious use of regen.

I don't claim to know exactly what percentage efficiency gains are to be had by a neutral switcher as versus a comparably skilled EV driver who does not make use of the hard-neutral option (rather than the near-zero option inherent to the pedal). One of the things I'm suggesting here to Nissan is not so much that I or others know the definitive answer, but that it sounds like it would be worth investigating on the modest chance that the gains are substantial enough to build into a more mainstream type function.
Former lessee 2012 SL
http://www.pluginamerica.org/surveys/ba ... hp?vid=229
2017-October: bght 2013 Volt
will buy 150+ mile BEV when they become less expensive on used market
opinions expressed are my own

Return to “Suggestions for Nissan”