# Set Regen to OFF...Please?



## El Matadurr (Feb 15, 2019)

Current Hyundai Ioniq driver here. Can select from 4 levels of regeneration, from 0 (coasting) to 1 (engine brake simulation) to 2 (typical hybrid regen) to 3 (near one-pedal driving). I've gotten my best efficiency when hypermiling--on trips I probably shouldn't be attempting--with regen set to 0. Any slowing down I need to do, I modulate the regen paddles and that covers me for 95% of the traveling. This feature is now common in all the Hyundai/Kia EVs, and I'm curious why a similar option isn't available on the Model 3, in what is Tesla's most efficient EV to date.

With regen set to low on my test drives the model 3 feels to coast at about a level 1.5, and on high is similar to level 3 (maybe a bit more). Since regen braking does most of the work when actually depressing the brake pedal anyway, I can't think of a reason why Regen set to OFF isn't available? Coasting in my Ioniq is one of the best feelings, and I can't imagine how many more effective miles this setting could provide on 55 mph country road trips I often take. 

Before you type it though, I know you can set the drive mode to neutral while driving to get effectively a coast going, but it isn't a very intuitive step (or safe, if you need to do an emergency acceleration). Could setting the regen levels be mapped to one of the control knobs as a custom setting, perhaps?


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## ADK46 (Aug 4, 2018)

Not sure I’ve read your post correctly, but the brake pedal of the 3 does not invoke regen. 

You can coast a 3 by positioning the go pedal at some intermediate position. The upper left bar graph display should show neithe black or green. 

Good hypermiling on any car means avoiding braking, including by regen. You get only about half the energy back from regen. The trick is not storming towards stoplights.


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## El Matadurr (Feb 15, 2019)

I thought the 3, like most EVs/hybrids, uses the brake pads primarily for coming to a complete stop and for emergency fast stopping...? The rest was regenerative braking, or no?


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## Ed Woodrick (May 26, 2018)

El Matadurr said:


> Current Hyundai Ioniq driver here. Can select from 4 levels of regeneration, from 0 (coasting) to 1 (engine brake simulation) to 2 (typical hybrid regen) to 3 (near one-pedal driving). I've gotten my best efficiency when hypermiling--on trips I probably shouldn't be attempting--with regen set to 0. Any slowing down I need to do, I modulate the regen paddles and that covers me for 95% of the traveling. This feature is now common in all the Hyundai/Kia EVs, and I'm curious why a similar option isn't available on the Model 3, in what is Tesla's most efficient EV to date.
> 
> With regen set to low on my test drives the model 3 feels to coast at about a level 1.5, and on high is similar to level 3 (maybe a bit more). Since regen braking does most of the work when actually depressing the brake pedal anyway, I can't think of a reason why Regen set to OFF isn't available? Coasting in my Ioniq is one of the best feelings, and I can't imagine how many more effective miles this setting could provide on 55 mph country road trips I often take.
> 
> Before you type it though, I know you can set the drive mode to neutral while driving to get effectively a coast going, but it isn't a very intuitive step (or safe, if you need to do an emergency acceleration). Could setting the regen levels be mapped to one of the control knobs as a custom setting, perhaps?


A number of slight issues in your statement. As ADK46 indicates, the Model doesn't invoke regen with the brakes, only by taking foot off of accelerator. And that means that to do the same thing, you want regen set on high and then reduce the accelerator.

And your best hypermiling could be done with regen set to full, you just let off the accelerator instead of using the regen paddles. It is much easier to accomplish. Basic thing is to never move the accelerator fast or by much. When you are truly hypermiling, you don't really want to use the brakes at all, or even regen. braking wastes all energy, regen at least returns a bunch of it. So using a EV with regen at its max, comes really close to never using brakes, because the energy is recovered.

The big difference is probably in your definition of coast. An EV isn't necessarily the best when coasting, and to achieve coasting in an EV takes a little work. You have to slowly reduce accelerator in most EVs to coast, otherwise regen kicks in.

The real item that you should research is what is the efficiency of regen.

But full regen is by far the most efficient way to drive a Tesla.

And then a Tesla isn't meant to be a really efficient vehicle, it's designed to a really efficient AND really fun to drive car. And it is designed to be a car that you should just drive, not one that you need to think about as special.


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## mswlogo (Oct 8, 2018)

Regardless of the brake pedal not envoking regen. I like his request. 

And if his request of 0 regen was given. Then it could envoke regen only when braking (silly not to). 

Coasting is more efficient than regen.


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## Robbo (Jan 19, 2017)

Can’t agree that coasting is better than Regen. It all depends on the situation and they are not either/or options. If you’re approaching red lights, at or around the speed limit, then coast until you need to slow down and use Regen instead of brakes, as far as possible. Downhill, use slight Regen to keep at or around the speed limit - coasting just gets you a ticket! Uphill, coasting isn’t an option, so maintain speed until you judge Regen will get you to a stop when you need to. It’s great fun developing these skills, and I really don’t think you want to cancel Regen. Think of all the fun, skill and judgement you’d forgo!
Robbo


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## GDN (Oct 30, 2017)

Please don't dumb this extremely incredible car down to the level of those that don't do it the same way. As much as I've made it known I'm not a "green" person, I'm coming on board to this car for its tech, for its capabilities, and for the things Tesla stands for. I agree it is your right to ask for a feature on this car as much as it is mine, but you are asking for something to alter the way Tesla believes the drive train should work and behave. You are talking about a setting which would allow the car to not recoup some of it's braking energy. In my mind this goes against what an electric car is about. You don't waste the energy coasting or braking, you recoup it and put it back in the battery. 

I get that you might be saying you can save energy to propel the car by just letting it coast and not giving it "gas", but that isn't how Tesla has designed it, it doesn't fit their model nor their many years of extreme intelligence and knowledge and brain power. As noted, there is a place you can feather the pedal to get no power and no regen, but it takes a little to get ahold of that. 

Otherwise just don't dumb this car down. Hypermile the Ioniq and the Prius all day long, but don't mess with my 3.


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## ADK46 (Aug 4, 2018)

mswlogo said:


> Coasting is more efficient than regen.


I guess the term "coasting" may need clarification. There's the kind you do with manual transmissions: take the car out of gear. There's the kind we typically do with automatics - just lift off the gas (engine braking is not very strong with automatics). I would not call taking one's foot off the "gas" in an EV "coasting" if it applies any kind of regen: lifting off is _braking_. Coasting in a Tesla can only be simulated by keeping your foot on the pedal at a position that neither draws or generates electricity. (I imagine that is what "N" does - true coasting is impossible since there is no way to disconnect the wheels from the motor(s) and reduction gears).

Coasting is more efficient because it means you are trying to use aero and rolling resistance to slow the car for a stoplight, as much as possible. That means you're planning way ahead, and not going too fast as you approach a light. Please don't do this when I'm behind you!


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## garsh (Apr 4, 2016)

El Matadurr said:


> Since regen braking does most of the work when actually depressing the brake pedal anyway,


Note, however, that pressing the brake pedal doesn't add any regen. Regen in a Tesla is controlled solely by adjusting the accelerator.


> I can't think of a reason why Regen set to OFF isn't available?


As @ADK46 explained above, you can get coasting by modulating the accelerator position until the screen shows no green regen bar as well as no grey power bar. It's not as easy as taking your foot off of the accelerator in an Ioniq, but it is possible.


> I can't imagine how many more effective miles this setting could provide on 55 mph country road trips I often take.


With practice, you can get just as good efficiency in your Ioniq no matter the regen setting. You just need to practice holding the accelerator at a position where no acceleration or regen occurs. Same thing with a Tesla.

All that said, I too think it would be nice if there was an easier way to obtain "0-power coasting" than to hold the accelerator at a particular position. That can be difficult to do when the road is a little bumpy.


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## El Matadurr (Feb 15, 2019)

Looks like I unintentionally stirred the pot, so let me clarify some things.

1. I didn't know that regen _only _happens when the foot lets off the accelerator. In every EV/hybrid I've driven, it gives regen when letting off the accelerator and then adds even more regen when the brake pedal is applied, then only using the friction brakes for a complete stop and for an emergency fast stop.

2. I did not know coasting in EVs was that hard. My ioniq does it so well on level 0 I just assumed that if any EV could turn its regen off it would in turn coast smoothly.

3. Coasting is _always_ more efficient than using regenerative braking when attempting to extend range, be it hypermiling or not. This is with the caveat that you coast as much as desired (a whole lot if no traffic and no one tailing you), then you use the regen _only_ to slow yourself down when needed.

4. I am not trying to radically change the way a Tesla drives, nor am I trying to change the way others use their Tesla. I figured with all the awesome updates the cars have gotten over the years, an option like this being added would be no big deal and could help people like me extend range. In cold climates like where I currently live a little can go a long way. Others can keep their regen on as they please.

5. The reasons I don't buy into using the power meter lines on the screen to essentially coast are not only that it's a pain to keep an eye on the screen all the time to get the sweet spot, but also if this feature was available, it would be easier on the legs/knees to simply take the foot off the accelerator as I do now with the Ioniq.

6. I'm not a "green" person. Biggest reasons why I hopped on the EV train were the performance, efficiency, and smooth driving dynamics. I may end up getting a P3D, and even then, I would enjoy using it as efficiently as possible when I'm not trying to show off.

I'll try to be a little less vague in future posts.


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## Frully (Aug 30, 2018)

I think one of the main reasons they don't use motor regen more aggressively, and why the brake pedal doesn't invoke regen is that it's really complicated to modulate 'anti-lock regen'. With brake pads you hydraulically vibrate them. With the motor it's a lot of 'spring' in the drivetrain to try and modulate during slip times. /aside
I understand where OP is coming from but really thing as suggested the 'feather throttle' technique is best rather than giving up all regen given the limitations of no-brake-pedal-forgiveness.


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## FRC (Aug 4, 2018)

@El Matadurr , Nothing wrong with either of your posts. Just some disagreement with your opinion. That part of the beauty of the forum. Welcome to M3OC!


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## ADK46 (Aug 4, 2018)

I always fret about terminology. People often call the gas pedal the throttle in ICE cars; there are situations where this is very confusing. People will ask "How do I adjust the throttle?" and half the answers will focus on the wrong thing. Here, I'm currently struggling with what people mean when they use the term "odometer".

There is one situation where zero regen would be great for me: when the road is slippery. When trying to slow down in dodgy conditions, you need to very sensitively control the force on the wheels, whether forward or back. Maybe ABS, stability control and traction control can be a substitute, but I don't like the jerkiness - gotta be smooth, and if you're good at it, you can stop more quickly. I am _not_ good at feathering the friction brakes while trying to prevent regen with the go pedal.

In fact, I'd like a "snow" button that set the car to chill mode, turn regen to zero, turn on slip start, and invoke a control system that tunes itself to the conditions. A bigger dream is a car with a motor for each wheel and a clever system to control them.


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## Tom Hudson (Dec 20, 2017)

The only thing I kind of wish for is an adjustable "coast" deadband on the accelerator pedal, where no acceleration or regen occurs. The current coasting zone of the Model 3 accelerator travel is very small, making it somewhat touchy to coast. Our old EV had more room in the pedal travel where you could easily coast.

The rule of regen is: only use regen if you actually need to slow down, because regen isn't 100% efficient.


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## Ed Post (Sep 18, 2018)

I'd like a "Regen off" option for another reason: when I'm driving in snow-slick conditions, I'd like to be able to get my foot off the accelerator and get no regen because traction control in regen is not very good, whereas ABS is really excellent. Coming down hill on packed snow, I'd have to modulate the accelerator to zero regen with one foot and apply the brake with the other to achieve this.

I do set regen to "low" in this situation (and it helps), but "off" would be much better.


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## MelindaV (Apr 2, 2016)

El Matadurr said:


> I did not know coasting in EVs was that hard.


I don't think anyone here is saying that it is. I am sure it is different for everyone, depending on what type of car they previously drove, but for me (having spent the prior near 20 years driving 5-speed sport cars) getting the feel for coasting smoothly took about an hour driving and then haven't given it any thought since.


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## JasonF (Oct 26, 2018)

El Matadurr said:


> 1. I didn't know that regen _only _happens when the foot lets off the accelerator. In every EV/hybrid I've driven, it gives regen when letting off the accelerator and then adds even more regen when the brake pedal is applied, then only using the friction brakes for a complete stop and for an emergency fast stop.
> 
> 2. I did not know coasting in EVs was that hard. My ioniq does it so well on level 0 I just assumed that if any EV could turn its regen off it would in turn coast smoothly.
> 
> 3. Coasting is _always_ more efficient than using regenerative braking when attempting to extend range, be it hypermiling or not. This is with the caveat that you coast as much as desired (a whole lot if no traffic and no one tailing you), then you use the regen _only_ to slow yourself down when needed.


I believe I might be able to address these three items, since I started out using "Low" regen:

1. The Model 3 _always_ regens. It does so to a much lesser extent when you use the brake, because pads and rotors are much better at reducing speed. Remember the early reviews that the Model 3 had a ridiculously long stopping distance, and they fixed it through a software update? That's why. They reduced the regen and increased the braking power. Supposedly they anticipated the motor providing more resistance, and it didn't pan out.

2. ICE cars do something called engine braking. If you accelerate just a tiny bit, the engine doesn't provide enough power to speed the car up, so the engine compression drags the speed down instead. If you use "Low" regen, you can do the same thing with a Tesla - except the "compression" is the motor engaging just enough to slow the car and return some power to the batteries. Letting off the accelerator altogether will allow you to coast a bit with just a little bit of resistance from regen ("Standard" will slow the car right away). See #3 for more.

3. Think of the two regen settings this way: "Low" regen nearly disengages the engine when you let off the accelerator, so you can coast a bit, and you either have to use the brakes to slow down, or lightly use the accelerator to re-engage the motor and provide more regen. In "Standard", the motor is always engaged, and you can only coast in neutral.

3a. The "Low" or "Standard" setting is dependent on your driving style and tastes, and there's no right way to use either. In either case, the laws of physics guarantee that coasting (in neutral) will never be as efficient as using _some _regen. Especially since the car's electronics are still powered while you coast, and the tires themselves provide energy-wasting resistance.


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## PNWmisty (Aug 19, 2017)

Ed Post said:


> I'd like a "Regen off" option for another reason: when I'm driving in snow-slick conditions, I'd like to be able to get my foot off the accelerator and get no regen because traction control in regen is not very good, whereas ABS is really excellent. Coming down hill on packed snow, I'd have to modulate the accelerator to zero regen with one foot and apply the brake with the other to achieve this.
> 
> I do set regen to "low" in this situation (and it helps), but "off" would be much better.


I've been using the "High" regen setting in some fairly steep and pretty slick conditions (greasy wet snow that packs into greasy, wet ice and prevents the tires from contacting the road). You're right, it won't stop the car as fast as ABS braking. But Tesla took care of that. No need to butt pucker. As soon as the regen causes too much wheel slippage, it backs right off and doesn't come on right away again. So you can simply go from the accelerator to brake with your right foot and if you need to slow down faster than regen only will achieve then step on the brake too. If you're slipping much regen will have already backed off on its own accord and will not impact ABS braking.

I've done this a bunch of times (>50) in a variety of snowy and icy conditions and regen always backs way off before it causes any trouble. That said, Tesla still recommends low regen for snow and ice and I think that will provide a more consistent driving experience when it's really slippery but I don't think it's much, if any, safer. Because regen backs way off and stays off if it starts to cause much sliding.


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## mswlogo (Oct 8, 2018)

Robbo said:


> Can't agree that coasting is better than Regen. It all depends on the situation and they are not either/or options. If you're approaching red lights, at or around the speed limit, then coast until you need to slow down and use Regen instead of brakes, as far as possible. Downhill, use slight Regen to keep at or around the speed limit - coasting just gets you a ticket! Uphill, coasting isn't an option, so maintain speed until you judge Regen will get you to a stop when you need to. It's great fun developing these skills, and I really don't think you want to cancel Regen. Think of all the fun, skill and judgement you'd forgo!
> Robbo


Coasting IS more efficient. The problem is, you can't always coast. So regen is better than brakes. But it's not more efficient than coasting.

You put X energy into the car. If you let all that energy apply to moving the car until it stops, that's as efficient as you can get. Now if you stopped SOONER with regen you inefficiently put some of that energy back into the battery. Now use that energy to get going again until it's used up. You won't get as far as coasting or you'll need more energy to get there. Because you wasted 20% charging the battery. You will use more total energy recharging battery to store excess energy than you will by using it all to move the car. Using it all, is coasting.

The OP isn't asking to "dumb it down". He's asking for an option to drive more efficiently (for those that wish to).

Keep in mind though it could partly be a safety issue. There is some controversy over "hyper miling" with a stick shift. In that it's unsafe to put the car in Neutral. We did it all the time on our ICE cars. My wife would routinely get 38-40 mpg out of a car rated at 31 mpg. It didn't feel unsafe but there is hot discussion that it is unsafe. Some drag is safer. It's kind of like the creep on vs creep off debate. I'd still want the OP's suggestion though. I think efficiency would go up.

Those 20" wheels would look even worse.


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## Oyster Bait (Sep 15, 2018)

I'm with the OP and those that would like the zero regen option. I'm sure I can drive more smoothly with zero regen and I'll take the efficiency hit for the times I would use it. I still doubt I'll ever need brake pads.

But a feature that I would find almost more important is an ability to adjust regen level simply, on the fly without opening the driving controls menu. Say you're driving along with low regen and come upon a long downhill stretch where you really "need" regular regen. Having to fiddle with the touchscreen can be a dangerous few seconds of distraction.


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## El Matadurr (Feb 15, 2019)

mswlogo said:


> Those 20" wheels would look even worse.


Inversely, those 20" wheels would look _better_ compared to the 18/19" using the other regen settings. 

Though to be honest, it would only slightly close the gap. No way it can make up fully for the efficiency of the single motor RWD with 18" aeros.



Oyster Bait said:


> I'm with the OP and those that would like the zero regen option. I'm sure I can drive more smoothly with zero regen and I'll take the efficiency hit for the times I would use it. I still doubt I'll ever need brake pads.
> 
> But a feature that I would find almost more important is an ability to adjust regen level simply, on the fly without opening the driving controls menu. Say you're driving along with low regen and come upon a long downhill stretch where you really "need" regular regen. Having to fiddle with the touchscreen can be a dangerous few seconds of distraction.


Bingo. The Ioniq's paddles are very intuitive. A similar function can and should be mapped to the buttons on the steering wheel if desired.


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## PNWmisty (Aug 19, 2017)

mswlogo said:


> Coasting IS more efficient. The problem is, you can't always coast. So regen is better than brakes. But it's not more efficient than coasting.


Sometimes regen can be used to an efficiency advantage instead of coasting. One example:

You're driving on a 50 mph road with occasional intersections controlled with stop lights. Looking ahead you see traffic backed up behind a red light. Rather than going into coast mode immediately, sometimes it's better to apply a little regen, say to slow down to 40 mph, then coast into the traffic. When timed properly, the rear of the "pack" is already starting to move when you arrive and you can flow in behind the accelerating traffic perhaps only having slowed to 30 mph.  Had you not applied regen, but simply coasted, you might have had to come to a complete stop.

As long as traffic behind you can see the red light, and all the traffic stopped ahead, it would be unusual for someone behind to become upset that you had scrubbed off 10 mph in anticipation. Occasionally someone behind will zip around you but then they feel pretty stupid when they have to immediately hit their brakes.

Bonus: You have helped the cars behind you save some gas because they will have backed off their throttle a little earlier than they would have otherwise.


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## mswlogo (Oct 8, 2018)

PNWmisty said:


> Sometimes regen can be used to an efficiency advantage instead of coasting. One example:
> 
> You're driving on a 50 mph road with occasional intersections controlled with stop lights. Looking ahead you see traffic backed up behind a red light. Rather than going into coast mode immediately, sometimes it's better to apply a little regen, say to slow down to 40 mph, then coast into the traffic. When timed properly, the rear of the "pack" is already starting to move when you arrive and you can flow in behind the accelerating traffic perhaps only having slowed to 30 mph.  Had you not applied regen, but simply coasted, you might have had to come to a complete stop.
> 
> ...


Yes, regen is good for unplanned (usually more aggressive) stops, other wise you need to use more brakes.

But as the OP suggested, if they did offer Level 0 Regen (coasting), they could enable regen, only when you hit the brakes. You could have the best of both ways that way. 
The "regen while hitting brakes" could be fairly aggressive and dynamic as well.


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## mswlogo (Oct 8, 2018)

BTW, right now the system is forcing you to use Regen when you don't want it (coasting) and doesn't use more aggressive regen when you do want it (braking).


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## PNWmisty (Aug 19, 2017)

mswlogo said:


> BTW, right now the system is forcing you to use Regen when you don't want it (coasting) and doesn't use more aggressive regen when you do want it (braking).


There is no regen when I'm coasting, that only happens when I lift my foot off the accelerator. And full regen is usually stronger than I want so I typically don't ever lift my foot off entirely until I'm going 5 mph or less.

The car never "forces" you to use regen!


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## John (Apr 16, 2016)

I love single pedal driving, but I don't see anything wrong with an option to disable regen if other people might prefer it.
I do think it would have a negative effect on range in most cases, though, and I'm just against extra levers.


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## El Matadurr (Feb 15, 2019)

PNWmisty said:


> The car never "forces" you to use regen!


He's referring to how you can't take your foot off the accelerator without it using regen, aside from popping the vehicle in neutral (which is dangerous in some aspects). Taking a foot off is a lot easier than modulating it to get the exact position of neither power going to the engine or power coming from it, especially if living in any area that isn't flat.


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## Long Ranger (Jun 1, 2018)

mswlogo said:


> You put X energy into the car. If you let all that energy apply to moving the car until it stops, that's as efficient as you can get. Now if you stopped SOONER with regen you inefficiently put some of that energy back into the battery. Now use that energy to get going again until it's used up. You won't get as far as coasting or you'll need more energy to get there. Because you wasted 20% charging the battery. You will use more total energy recharging battery to store excess energy than you will by using it all to move the car. Using it all, is coasting.


Actually, the calculation isn't quite that simple. You're ignoring drag. At high enough speeds it's actually possible for regen to be more efficient than coasting. A vehicle coasting at a high a rate of speed is wasting a lot of energy to overcome drag. If you scrub off some of that speed using regen, you are now using less energy per mile by traveling at a lower speed with less drag loss. If the regen losses are less than the difference in drag losses, then regen is actually more efficient in that instance.

Even if coasting is more efficient at most speeds, I still wouldn't want a coasting option:
1. I'm very skeptical that it would show any meaningful efficiency gain vs. competent one-pedal driving with the current system. If it's appropriate to coast, then that's what I'm already doing via the accelerator position today. The fact that I might be going into regen a little bit shouldn't be significant in overall efficiency.
2. The coasting option just encourages driving patterns that are either annoying or unsafe. If someone is trying to eke out extra efficiency by coasting when they otherwise would have slowed using regen, then they are traveling faster than they would otherwise, and increasing the odds that they'll then need to suddenly brake.
3. Adding an option like this would likely mean a lot more testing for Tesla. This is something that affects some pretty fundamental driving characteristics. Tesla would likely need to repeat all of their braking, winter handling, accident avoidance, etc. testing for each mode of operation.


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## mswlogo (Oct 8, 2018)

PNWmisty said:


> There is no regen when I'm coasting, that only happens when I lift my foot off the accelerator. And full regen is usually stronger than I want so I typically don't ever lift my foot off entirely until I'm going 5 mph or less.
> 
> The car never "forces" you to use regen!


I know what you are saying.
I think if it really coasted it would feel quite different. Even in my Automatic ICE vehicle you can feel how much more it "free wheels" down hill. And that ICE still has some drive train drag. A manual transmission really gets going in neutral even more.

I have not looked at the energy graph when you partial throttle it down hill. To confirm or deny what you are saying. But even if it does do that, it's a bit of work to keep it exactly "neutral" (no drive and no regen).


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## PNWmisty (Aug 19, 2017)

El Matadurr said:


> He's referring to how you can't take your foot off the accelerator without it using regen, aside from popping the vehicle in neutral (which is dangerous in some aspects). Taking a foot off is a lot easier than modulating it to get the exact position of neither power going to the engine or power coming from it, especially if living in any area that isn't flat.


Kinda like the Model 3 forces you to floor it every time you want to accelerate? I just don't get that argument that you have to take your foot all the way off the accelerator pedal when you want to coast. The car is not forcing you to do anything.

Don't get me wrong, I'm not arguing against a menu option to reduce regen to zero, it's just that I would never use it because, well, it's a menu option. I basically don't want to be using any menu options while I'm driving. I would rather have a coast button or a paddle on the steering wheel that would override the regen while it was held. It could even be proportional. But that's not the car we have and its absence doesn't bother me. My point was that the Model 3 does not force you to use regen when you want to coast.


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## El Matadurr (Feb 15, 2019)

PNWmisty said:


> I'm not arguing against a menu option to reduce regen to zero, it's just that I would never use it because, well, it's a menu option. I basically don't want to be using any menu options while I'm driving. I would rather have a coast button or a paddle on the steering wheel that would override the regen while it was held. It could even be proportional. But that's not the car we have and its absence doesn't bother me.


Most menu options are a set one-and-done affair when parked, but aside from that we're in complete agreement.


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## mswlogo (Oct 8, 2018)

Long Ranger said:


> Actually, the calculation isn't quite that simple. You're ignoring drag. At high enough speeds it's actually possible for regen to be more efficient than coasting. A vehicle coasting at a high a rate of speed is wasting a lot of energy to overcome drag. If you scrub off some of that speed using regen, you are now using less energy per mile by traveling at a lower speed with less drag loss. If the regen losses are less than the difference in drag losses, then regen is actually more efficient in that instance.
> 
> Even if coasting is more efficient at most speeds, I still wouldn't want a coasting option:
> 1. I'm very skeptical that it would show any meaningful efficiency gain vs. competent one-pedal driving with the current system. If it's appropriate to coast, then that's what I'm already doing via the accelerator position today. The fact that I might be going into regen a little bit shouldn't be significant in overall efficiency.
> ...


Coasting HAS to be more efficient. It doesn't mean it's quicker or more convenient or safer. But to get from point A to B with NO BRAKES (including friction). Coasting is more efficient.

I think it could be VERY significant in the right situations, with the right driving technique.

Someone started a thread (forget which site, this site or TMC) and put his car in LOW Regen and claims he is getting significantly better wh/m. I believe him.
Tesla chose what they did for comfort/safety for the average driver. They might not want the perception of "thow must hyper mile" to get the best efficiency.

My guess is Tesla is very well aware of the trade-offs and made a choice from a business/pr point of view.

I've been testing my car with Heat OFF just for fun. My Regen is usually 70% limited every day because it's still cold around 30F. I'm getting 200 wh/m on AWD. !!!
Limited Regen makes no difference (unless I'm forced to use unplanned braking). I'm essentially coasting more.
Now if I had 0 regen, I'd have a hard time pulling it off around town. But on the highway 0 Regen (coasting) would be fine.


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## mswlogo (Oct 8, 2018)

El Matadurr said:


> Most menu options are a set one-and-done affair when parked, but aside from that we're in complete agreement.


I suspect if the Regen active when braking was on. 0 Regen would be a preferred, set it once and forget it. It would be a different style/feeling of driving.
Some folks like the one foot driving. But they are assuming that is maximum efficiency because they are not using the brake pedal.
Costing with "On Demand" regen on the brake is more foot work, but would highly likely be more efficient.

One other catch here is AutoPilot. What would it do  Would it let you gain speed down a hill? That might be partly why Tesla doesn't offer it. Things get complicated.


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## El Matadurr (Feb 15, 2019)

mswlogo said:


> One other catch here is AutoPilot. What would it do  Would it let you gain speed down a hill? That might be partly why Tesla doesn't offer it. Things get complicated.


Doubtful, even on my Ioniq in cruise control it will apply regeneration to stay at the selected speed, instead of letting the vehicle coast for the rubber banding effect needed to go around hills efficiently. Easy enough though to temporarily cancel cruise control in these instances.


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## PNWmisty (Aug 19, 2017)

mswlogo said:


> Some folks like the one foot driving. But they are assuming that is maximum efficiency because they are not using the brake pedal.
> Costing with "On Demand" regen on the brake is more foot work, but would highly likely be more efficient.


I think you are over-estimating the gains to be had by coasting. All the same auxiliary electrical losses will still be present. My experience is that when coasting on the neutral throttle, any inadvertent addition of power is so small as to be almost meaningless.


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## mswlogo (Oct 8, 2018)

El Matadurr said:


> Doubtful, even on my Ioniq in cruise control it will apply regeneration to stay at the selected speed, instead of letting the vehicle coast for the rubber banding effect needed to go around hills efficiently. Easy enough though to temporarily cancel cruise control in these instances.


But that's not coasting. And now "Cruise Control" (AutoPilot) will get blamed for costing efficiency. It would be consistent with Tesla's thinking in other areas. Like down grading EPA on RWD so that AWD option doesn't look like it cost range.

It's just a hunch, I have no idea. AP could do some "costing" and even set a limit of how far over you want it to allow going over set speed (for more efficiency).

I agree with your opening post obviously. It's completely logical. Just trying to figure out reasons why Tesla doesn't offer it.
I forget the technical reasons why "Neutral" on a Manual Stick is considered unsafe (by some people).


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## mswlogo (Oct 8, 2018)

PNWmisty said:


> I think you are over-estimating the gains to be had by coasting. All the same auxiliary electrical losses will still be present. My experience is that when coasting on the neutral throttle, any inadvertent addition of power is so small as to be almost meaningless.


I think the max it could gain is 20% (loss of regen charging).
I think it would be much easier to just let your foot off rather than constantly riding the throttle.

Seems other car manufactures thought it was worth offering the option. It would be interesting to look up how much difference they have.
It would be so trivial to offer on Tesla. And it might be just a preffered way for some to drive.


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## PNWmisty (Aug 19, 2017)

mswlogo said:


> I think the max it could gain is 20% (loss of regen charging).
> I think it would be much easier to just let your foot off rather than constantly riding the throttle.
> 
> Seems other car manufactures thought it was worth offering the option. It would be interesting to look up how much difference they have.
> It would be so trivial to offer on Tesla. And it might be just a preffered way for some to drive.


I hate it when people don't look at a vehicle as a whole but rather nitpick this and that detail and act like they could have done it better. But they didn't. There is only one Model 3 and, taken in it's entirety, it's a beautiful symphony. Like any car, it's not perfect, and different people are free to have different preferences, but it's hard to argue with the fact that it was the best selling luxury car in America last year.

You keep speaking of how "other car manufacturer's" do it but they don't have the best selling EV in America. Tesla does. The market is full of choices, pick the one that hits your check-boxes and stop second-guessing the talented people who made it. Or simply start your own car company and show them how it's done. Maybe you'll even be able to outsell the Model 3 once you jump through all the hurdles to get it into production.

Armchair quarterbacks, backseat drivers, gourmet food critics, there's an expert on every subject. But the real experts are out there making it happen.


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## mswlogo (Oct 8, 2018)

PNWmisty said:


> I hate it when people don't look at a vehicle as a whole but rather nitpick this and that detail and act like they could have done it better. But they didn't. There is only one Model 3 and, taken in it's entirety, it's a beautiful symphony. Like any car, it's not perfect, and different people are free to have different preferences, but it's hard to argue with the fact that it was the best selling luxury car in America last year.
> 
> You keep speaking of how "other car manufacturer's" do it but they don't have the best selling EV in America. Tesla does. The market is full of choices, pick the one that hits your check-boxes and stop second-guessing the talented people who made it. Or simply start your own car company and show them how it's done. Maybe you'll even be able to outsell the Model 3 once you jump through all the hurdles to get it into production.
> 
> Armchair quarterbacks, backseat drivers, gourmet food critics, there's an expert on every subject. But the real experts are out there making it happen.


Who says we are not happy with the car. It's awesome.

So we aren't allowed to propose and discuss an option that could make it more efficient?

Tesla may have very good reasons for not offering it, and I mentioned some of those. I wish it had better carpets and insulation too, but does that void all the things I like about the car?

I hate it when people can't look at things objectively and have a heathly discussion without going ballistic when someone questions why Tesla made a choice.
Maybe Tesla will release it later like heated back seats, blind spot warning and everyone will say, wow Tesla is Brilliant.

Some people want regen 0 for the track as well.


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## El Matadurr (Feb 15, 2019)

mswlogo said:


> Who says we are not happy with the car. It's awesome.
> 
> So we aren't allowed to propose and discuss an option that could make it more efficient?
> 
> I hate it when people can't look at things objectively and have a heathly discussion without going ballistic when someone questions why Tesla made a choice.


Nothing is sacred, everything and everyone is fallible to some degree. I can't agree more, the whole reason I want to get a Model 3 are the good things, but that doesn't mean that I will stop there. Especially with Tesla's commitment to OTA updates, we have the opportunity to press them to make the vehicles better and better every month. Seems constructive criticism is a hard concept to convey in text-based form on a forum.


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## mswlogo (Oct 8, 2018)

El Matadurr said:


> Nothing is sacred, everything and everyone is fallible to some degree. I can't agree more, the whole reason I want to get a Model 3 are the good things, but that doesn't mean that I will stop there. Especially with Tesla's commitment to OTA updates, we have the opportunity to press them to make the vehicles better and better every month. Seems constructive criticism is a hard concept to convey in text-based form on a forum.


Elon even encourages new ideas, thinking out of the box.


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## JasonF (Oct 26, 2018)

I have some real-world data for you. Today I drove 27.7 miles on suburban streets with regen set to "Standard". Started the day with 279 miles (90% charge) and ended it with 248. That means I had a loss of 3.3 miles of range in 9 hours - and that's with pre-cooling the car twice, once at lunch time and again before I drove home.

It would be really hard to beat that by being able to manipulate regen rates or coasting.


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## Ed Woodrick (May 26, 2018)

ADK46 said:


> I guess the term "coasting" may need clarification. There's the kind you do with manual transmissions: take the car out of gear. There's the kind we typically do with automatics - just lift off the gas (engine braking is not very strong with automatics). I would not call taking one's foot off the "gas" in an EV "coasting" if it applies any kind of regen: lifting off is _braking_. Coasting in a Tesla can only be simulated by keeping your foot on the pedal at a position that neither draws or generates electricity. (I imagine that is what "N" does - true coasting is impossible since there is no way to disconnect the wheels from the motor(s) and reduction gears).
> 
> Coasting is more efficient because it means you are trying to use aero and rolling resistance to slow the car for a stoplight, as much as possible. That means you're planning way ahead, and not going too fast as you approach a light. Please don't do this when I'm behind you!


BUT, in an ICE, when you are coasting, the engine is still burning gas. In an EV when you are coasting, you are neither using nor regenerating.
But coasting may not be as efficient as you may think. You've still got all of the drag and friction. If you are coasting to a stop without braking, that's about the only time that coasting is better. But then you're get yelled at.


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## PNWmisty (Aug 19, 2017)

mswlogo said:


> Who says we are not happy with the car. It's awesome.
> 
> So we aren't allowed to propose and discuss an option that could make it more efficient?
> 
> ...


LoL! No one went ballistic and you must not have read what I wrote. I'll write it again so you are clear on where I stand:

"Like any car, it's not perfect, and different people are free to have different preferences, but it's hard to argue with the fact that it was the best selling luxury car in America last year." Not to mention the best selling EV in America.

Now, what's your question again?


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## mswlogo (Oct 8, 2018)

PNWmisty said:


> LoL! No one went ballistic and you must not have read what I wrote. I'll write it again so you are clear on where I stand:
> 
> "Like any car, it's not perfect, and different people are free to have different preferences, but it's hard to argue with the fact that it was the best selling luxury car in America last year." Not to mention the best selling EV in America.
> 
> Now, what's your question again?


What's the best selling luxury car got anything to do with discussing a new option?

And do ya think customers gave Tesla any suggestions over the years to get there?


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## Luckyinnovato (Feb 19, 2019)

So when my wife has her iPhone 6s in the home and her phone rings it then gets answered on the model 3 which is parked down in the garage. This is annoying. Does anyone have a fix to this? Thank you.


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## Long Ranger (Jun 1, 2018)

mswlogo said:


> Coasting HAS to be more efficient. It doesn't mean it's quicker or more convenient or safer. But to get from point A to B with NO BRAKES (including friction). Coasting is more efficient.


 Not at all speeds. It depends upon the drag losses vs. regen losses. Coasting is using up the car's kinetic energy to overcome drag. Regen can store some of that energy and use it to potentially propel the car farther at lower speed against much lower drag.


mswlogo said:


> I think it could be VERY significant in the right situations, with the right driving technique.


 I can understand that some people may prefer the driving style where you can fully lift off the accelerator with no regen. But I don't understand why you think this will improve efficiency. When is all this wasted regen happening? 99% of my regen occurs when I want to slow down and I'd be using friction brakes otherwise. If I were to coast instead of using regen, it would just delay my braking, which wouldn't help efficiency at all.


mswlogo said:


> Someone started a thread (forget which site, this site or TMC) and put his car in LOW Regen and claims he is getting significantly better wh/m. I believe him.


And someone else recently posted that Consumer Reports got 350 miles of range on standard regen and 310 miles on low regen.


mswlogo said:


> Tesla chose what they did for comfort/safety for the average driver. They might not want the perception of "thow must hyper mile" to get the best efficiency.
> 
> My guess is Tesla is very well aware of the trade-offs and made a choice from a business/pr point of view.


I disagree, I think Tesla chose the more efficient option.



mswlogo said:


> I've been testing my car with Heat OFF just for fun. My Regen is usually 70% limited every day because it's still cold around 30F. I'm getting 200 wh/m on AWD. !!!
> Limited Regen makes no difference (unless I'm forced to use unplanned braking). I'm essentially coasting more.
> Now if I had 0 regen, I'd have a hard time pulling it off around town. But on the highway 0 Regen (coasting) would be fine.


 In terms of city vs. highway, city is definitely where regen provides a big benefit. I agree that it's of little benefit on the highway. But it's also of little cost on the highway. It just isn't used enough on the highway to make much difference one way or the other.


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## PNWmisty (Aug 19, 2017)

Long Ranger said:


> Not at all speeds. It depends upon the drag losses vs. regen losses. Coasting is using up the car's kinetic energy to overcome drag. Regen can store some of that energy and use it to potentially propel the car farther at lower speed against much lower drag.


That's a very insightful point and one that made me realize I've been doing it wrong at higher speeds.



> And someone else recently posted that Consumer Reports got 350 miles of range on standard regen and 310 miles on low regen.


I can believe it. That's 13% better than Low Regen. I can also see the possibility that someone who has inconsistent or erratic throttle control might get more range with low regen. But those with smooth and accurate throttle control will do better with regen left on high or "Standard". And I'm sure that's why Tesla calls high regen mode "Standard". Getting good range is all about momentum management (and of course avoiding higher speeds). I find the one pedal momentum management to be so much better than an ICE car it's not even a close contest.


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## ADK46 (Aug 4, 2018)

We can be quantitative - gasp! - on this subject.

Let's say you are going 60 mph (97 kph), and you see a stop sign way up ahead. A 4000-lb car has a kinetic energy of 652 kJ at this speed. How would you like to use this energy? The hyper-miler will start coasting early and let aerodynamic resistance, rolling resistance and drivetrain friction slow the car to a near-halt. Nearly 100% of the investment made to get the car up to 60 mph is returned to propel the car to the stop sign. 

The opposite approach is to wait until the last moment and send your open bag of Cheetos to the floor. All you get for your 652 kJ investment is hot brake rotors (and frequent brake jobs).

Another approach is available in an EV: employ regenerative braking (in a traffic-friendly fashion) and absorb 80% of the kinetic energy as electricity, or 522 kJ. About 65% of this will survive the round trip into and out of the battery storage system, or about 340 kJ. You'll be recovering 52% of the car's initial kinetic energy. 

Is that a lot? 340 kJ can be converted to kWh, another unit of energy: 0.095 kWh. At my $0.15/kWh rate, that's worth 1.4 cents. It may be more significant for brake life extension. Or keeping brake dust off your intricate wheels.

A big fan of regen might try to do 95% of his slowing without the friction brakes, by starting earlier. That works out to 1.7 cents worth of electricity recovered. I'm not properly accounting for the aero and RR braking forces, so this is an over-estimate.

The pure coaster will save 95% of the 652 kJ of energy without the battery round-trip losses. That's 0.18 kWh, worth 2.7 cents in electricity, more in gasoline. If an EV, an extra penny versus the 95% regen guy.

We're having an argument about one penny per stop sign. I'm enjoying it, so let's continue.


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## mswlogo (Oct 8, 2018)

Long Ranger said:


> Not at all speeds. It depends upon the drag losses vs. regen losses. Coasting is using up the car's kinetic energy to overcome drag. Regen can store some of that energy and use it to potentially propel the car farther at lower speed against much lower drag.
> I can understand that some people may prefer the driving style where you can fully lift off the accelerator with no regen. But I don't understand why you think this will improve efficiency. When is all this wasted regen happening? 99% of my regen occurs when I want to slow down and I'd be using friction brakes otherwise. If I were to coast instead of using regen, it would just delay my braking, which wouldn't help efficiency at all.
> 
> And someone else recently posted that Consumer Reports got 350 miles of range on standard regen and 310 miles on low regen.
> ...


So because consumers got 350 that means this won't improve further. Well that's sound reasoning to look no further.

Using all the kinetic energy vs storing it at a 20% loss will use less energy. Regen is a convenience over coasting. And can be used in more places like stop and go traffic. But in places like open highway going a fairly consistent speed and not to much traffic, coasting is more efficient.

How much coasting can be leveraged in more difficult situations. Depends on the the driver and their patience to apply it. Not for everyone. Just like a manual stick is not for everyone.


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## mswlogo (Oct 8, 2018)

ADK46 said:


> We can be quantitative - gasp! - on this subject.
> 
> Let's say you are going 60 mph (97 kph), and you see a stop sign way up ahead. A 4000-lb car has a kinetic energy of 652 kJ at this speed. How would you like to use this energy? The hyper-miler will start coasting early and let aerodynamic resistance, rolling resistance and drivetrain friction slow the car to a near-halt. Nearly 100% of the investment made to get the car up to 60 mph is returned to propel the car to the stop sign.
> 
> ...


At a cost of around $0.05 / mi for EV and a commute that I probably need to stop 2-3 times per mile. YEAH let's continue !!! I don't reach 60 mph each time. But if I save one penny per mile for several slower stops that's 20%. And my electricity is nearly twice yours.

Can you calculate the cost of tire wear per turn of the wheel?


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## MelindaV (Apr 2, 2016)

mswlogo said:


> BTW, right now the system is forcing you to use Regen when you don't want it (coasting)


You coast with your foot still on the accelerator pedal There is no need to engage regen when coasting.


mswlogo said:


> and doesn't use more aggressive regen when you do want it (braking).


You are using regen whenever you lift your foot off the accelerator, so by nature, you are getting Regen while pressing the brake, but not because of the brake pedal being pressed.


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## garsh (Apr 4, 2016)

MelindaV said:


> ...accelerator peddle....
> 
> ...brake peddle...


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## mswlogo (Oct 8, 2018)

MelindaV said:


> You coast with your foot still on the accelerator peddle. There is no need to engage regen when coasting.
> 
> You are using regen whenever you lift your foot off the accelerator, so by nature, you are getting Regen while pressing the brake, but not because of the brake peddle being pressed.


I don't believe you are coasting when you throttle the throttle down hill. It might be. But its also a PITA. Now maybe only being close, is close enough. But the car does not feel like free wheeling down a hill. When regen is 0 due to cold, It feels VERY different, and feels like it's really free wheeling.

It feels like the regen power goes to drive the car when "coasting" now. So your net power is 0. But it's not really coasting.

The Regen on brake idea. Would ONLY engage it when you hit the brake. And be proportional to how much braking you are using. Right now it's completely decoupled by how much you want to stop. It always runs in "one pedal" mode regardless of what the brake pedal is doing.


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## MelindaV (Apr 2, 2016)

garsh said:


> View attachment 22174


see, using the iPad at 6am without glasses is never good


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## MelindaV (Apr 2, 2016)

mswlogo said:


> The Regen on brake idea. Would ONLY engage it when you hit the brake.


one of my favorite things about this car is the 1 pedal driving.


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## gary in NY (Dec 2, 2018)

Oyster Bait said:


> But a feature that I would find almost more important is an ability to adjust regen level simply, on the fly without opening the driving controls menu. Say you're driving along with low regen and come upon a long downhill stretch where you really "need" regular regen. Having to fiddle with the touchscreen can be a dangerous few seconds of distraction.


This is where I like the paddle regen on the Chevy Bolt. When I drove one a while back, I found that I could control the amount of regen from none to a full stop. It was very useful on a long steep downhill with a stop sign at the bottom. The M3D, as currently configured, does not behave the same on this downhill, although there could be other factors at work such as temperature and state of charge.

EDIT: I made my reply before I read to the end of this tread, and it now seems somewhat off topic. My personal feeling is that the M3 is set up for the most generally efficient use, which may not be the most efficient use for all owners. I also love the one pedal driving, although that's not possible at my current local temperatures (below 32), and for most all practical purposes the overall efficiency is adequate.

AND, I agree that the option of "no regen" should be an option, and those that want to use it may do so, and those that do not, may not.


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## ADK46 (Aug 4, 2018)

Unless I missed it, no one has yet spelled brake "break" in this thread. Excellent!

I'm puzzled about the point of coasting when it comes to long downhills. If the idea is to go a certain speed, you'll usually need either power on a gradual hill, or braking on a steep hill. If you aren't trying to maintain a certain speed, you can always get to the bottom without tapping the battery, but you have the option to put energy into your battery. Coasting is not more efficient. But perhaps people are talking about the convenience of lifting off entirely.


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## msjulie (Feb 6, 2018)

Options are fine and generally I'm in favor of them but I wonder what caveats Tesla would need to provide to educate folks about the side effects of zero regen. Currently they make claims about reduced brake wear etc (which is true) because friction braking is supplemented with regenerative braking.

Teslas, all of them, are pretty heavy cars thus requiring a fair amount from the brakes if zero regen. Some have suggested that Tesla brakes are *undersized* specifically because they size them for the whole system ie that regen will be a part of every stopping experience at least to some degree.

FWIW (like free advice, not much likely  ) I have modified my brake rotors with larger MPP rotors and I can tell the difference in braking performance just on the street. The stock brakes were fine, these stop better but I still will always leave my regen set to it's max settings. 

BTW I have no affiliation with MPP other than a customer.


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## mswlogo (Oct 8, 2018)

MelindaV said:


> one of my favorite things about this car is the 1 pedal driving.


I like it too. I like eeking out watts too.

And nobody is proposing taking that away. But don't assume it's the most efficient way to operate an EV.


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## mswlogo (Oct 8, 2018)

msjulie said:


> Options are fine and generally I'm in favor of them but I wonder what caveats Tesla would need to provide to educate folks about the side effects of zero regen. Currently they make claims about reduced brake wear etc (which is true) because friction braking is supplemented with regenerative braking.
> 
> Teslas, all of them, are pretty heavy cars thus requiring a fair amount from the brakes if zero regen. Some have suggested that Tesla brakes are *undersized* specifically because they size them for the whole system ie that regen will be a part of every stopping experience at least to some degree.
> 
> ...


Using 0 regen to "hyper mile" shouldn't use that much more brakes if used correctly. But if regen DOES kick in dynamically with brake force (as the OP also asked for), the "pair" of proposed options should not use more brake pads. They go hand in hand.

In fact 0 regen with regen on braking might use less brake pads.

Technically low regen will use slightly more brakes too. So why not add one more notch?


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## garsh (Apr 4, 2016)

mswlogo said:


> But if regen DOES kick in dynamically with brake force....


Ugh, no.
Nissan does that with the Leaf. The blending is hard to get right. It's a bad experience, especially when you hit a bump on a steep downhill.


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## mswlogo (Oct 8, 2018)

garsh said:


> Ugh, no.
> Nissan does that with the Leaf. The blending is hard to get right. It's a bad experience, especially when you hit a bump on a steep downhill.


Interesting. I wouldn't think it would be that hard to get right. Sounds like OP has it on his Ionic as well and likes the overall scheme of 0 regen with regen on Braking.
I wouldn't extrapolate one implementation to others.


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## garsh (Apr 4, 2016)

mswlogo said:


> Interesting. I wouldn't think it would be that hard to get right. Sounds like OP has it on his Ionic as well and likes the overall scheme of 0 regen with regen on Braking.


OP is from Illinois. That's the second-flattest state in the union. OP doesn't have to deal with real hills.


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## PNWmisty (Aug 19, 2017)

ADK46 said:


> Unless I missed it, no one has yet spelled brake "break" in this thread. Excellent!


I'm thankful for small miracles and large miracles alike! I believe this belongs in the latter category.


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## mswlogo (Oct 8, 2018)

garsh said:


> OP is from Illinois. That's the second-flattest state in the union. OP doesn't have to deal with real hills.


So it's an OPTION that might work better for some than others. I would assume the folks in Hawaii or Southern CA don't use "Slip Start" very much either.

OP isn't asking that anything change the way it operates now. He asked for a couple more dials that some folks might use and others won't.
Possibly just one more slide position in an existing control (Off, Low, Standard) and perhaps Off automatically enables regen braking.


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## John (Apr 16, 2016)

One thing to keep in mind: it's all software with a Tesla.
Tesla could add a toggle on the Driving tab, for instance: Coast on Open Freeway
Whenever you are on a freeway and there's no one very close in front of you, regen is disabled above a certain speed.


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## PNWmisty (Aug 19, 2017)

John said:


> One thing to keep in mind: it's all software with a Tesla.
> Tesla could add a toggle on the Driving tab, for instance: Coast on Open Freeway
> Whenever you are on a freeway and there's no one very close in front of you, regen is disabled above a certain speed.


That's actually a good idea if it could be implemented without raising new issues. But I don't see how that would work if I'm happily coasting down an incline of sufficient slope to maintain 65 MPH when I come upon traffic in front. How does the car handle it? Does it start to blend in regen and how does it do that in a predictable manner?

Also, there is reduced safety without regen on the freeway. One of the big plusses that I'm sure was in mind when Tesla developed the system the way they did is that braking begins as soon as the drivers foot is lifted from the accelerator. This means the car is already slowing down by the time the driver's foot hits the brake which provides an important safety advantage at all speeds but especially at freeway speeds..


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## mswlogo (Oct 8, 2018)

PNWmisty said:


> That's actually a good idea if it could be implemented without raising new issues. But I don't see how that would work if I'm happily coasting down an incline of sufficient slope to maintain 65 MPH when I come upon traffic in front. How does the car handle it? Does it start to blend in regen and how does it do that in a predictable manner?
> 
> Also, there is reduced safety without regen on the freeway. One of the big plusses that I'm sure was in mind when Tesla developed the system the way they did is that braking begins as soon as the drivers foot is lifted from the accelerator. This means the car is already slowing down by the time the driver's foot hits the brake which provides an important safety advantage at all speeds but especially at freeway speeds..


Keep in mind Regen isn't always present. So if it was purely a safety issue, it would be unsafe at 100% SOC (which doesn't last long) and below 0F, that can be nearly no regen for a very long time.

I mentioned a few posts back that part of the reasoning might be AutoPilot (maintaining speed down hill). But again, it's all software. Perhap 0 Regen is disabled on AutoPilot.
Or as you said AutoPilot could dynamically kick in regen as needed. The OP requested engaging regen when braking, well AutoPilot can use that in exactly the same way to slow down.
I would not expect AutoPilot to "hypermile". But in Theory it easily could. It has all the tools to do it extremely well. It can probably predict the best times to use regen, brake or coast.
User could set a tolerance of how much over speed to allow.


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## John (Apr 16, 2016)

PNWmisty said:


> That's actually a good idea if it could be implemented without raising new issues. But I don't see how that would work if I'm happily coasting down an incline of sufficient slope to maintain 65 MPH when I come upon traffic in front. How does the car handle it? Does it start to blend in regen and how does it do that in a predictable manner?
> 
> Also, there is reduced safety without regen on the freeway. One of the big plusses that I'm sure was in mind when Tesla developed the system the way they did is that braking begins as soon as the drivers foot is lifted from the accelerator. This means the car is already slowing down by the time the driver's foot hits the brake which provides an important safety advantage at all speeds but especially at freeway speeds..


Perhaps. Though I don't count "coasting" as one of those things a person can do that a Tesla can't. And I'd bet there are times, like in the rain or in heavy traffic, when the car would be better.


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## El Matadurr (Feb 15, 2019)

ADK46 said:


> We're having an argument about one penny per stop sign. I'm enjoying it, so let's continue.





mswlogo said:


> Can you calculate the cost of tire wear per turn of the wheel?





garsh said:


> View attachment 22174


I'm starting to like you guys.


mswlogo said:


> Interesting. I wouldn't think it would be that hard to get right. Sounds like OP has it on his Ionic as well and likes the overall scheme of 0 regen with regen on Braking.
> I wouldn't extrapolate one implementation to others.


Correct, except to my surprise the Ioniq implements the blend very smoothly, down to 5 mph where it fully transitions to friction brakes. The only scenario where things get jarring are where another poster mentioned heavy bumps. The change in momentum in long breaks in the road or big bumps really messes with some sensor and regen rubber-bands for a split second. Feels like slipping on ice, in a way.


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## John (Apr 16, 2016)

El Matadurr said:


> I'm starting to like you guys.
> 
> Correct, except to my surprise the Ioniq implements the blend very smoothly, down to 5 mph where it fully transitions to friction brakes. The only scenario where things get jarring are where another poster mentioned heavy bumps. The change in momentum in long breaks in the road or big bumps really messes with some sensor and regen rubber-bands for a split second. Feels like slipping on ice, in a way.


You know, this reminds me of Toyota braking software in the Prius (we've owned three, currently have two). It's often held out as being good at blending brakes and regen (the brake pedal starts applying regen, and blends in brakes), but the exception is road roughness.

When there is a big bump the braking starts anti-lock pulsing even when-to me at least-it seems that it shouldn't. It is very disconcerting to lose braking for few seconds when you need it and have lost it just because the car was rattled by a quick pot hole.

It has never quite risen to the level of "this software is dangerous," but we all consider it pretty sus and don't trust it much. It's JUST rare enough that it's acceptable.


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## garsh (Apr 4, 2016)

John said:


> When there is a big bump the braking starts anti-lock pulsing even when-to me at least-it seems that it shouldn't. It is very disconcerting to lose braking for few seconds when you need it and have lost it just because the car was rattled by a quick pot hole.
> 
> It has never quite risen to the level of "this software is dangerous," but we all consider it pretty sus and don't trust it much. It's JUST rare enough that it's acceptable.


Nissan's regen/brake blending with anti-lock is absolutely horrible. As soon as you hit a bump, you lose ALL regen until you take your foot completely off the brake pedal. Additionally, the anti-lock reduces brake force longer than necessary, so the end result is that if you hit a bump going down a steep hill, you immediately start accelerating.

There's one hill in particular in Pittsburgh that I travel often that is really bad. I've taken my Model 3 on in several times to see how it would handle it. It's been awesome. I could barely even tell that I hit a bump. The anti-lock seems to be ridiculously quick, and gets right back onto full braking. If I pay attention to the screen, I'll see a sharp decrease in regen, which comes right back to full in a fraction of a second. It's so quick that I don't even notice that it had dropped out other than the display of the regen bar on the screen.


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## ADK46 (Aug 4, 2018)

The Prius "combo" break peddle brake pedal works pretty well, but there is one situation where it doesn't. If I hit a patch of snow or ice on the right side while regen braking, the differential means there is suddenly hardly any braking at all even though the left wheel is on dry pavement. This is an unpleasant surprise. The control system activates the friction brakes almost immediately, but not instantly.

This must happen in all EV's during regen but I've not yet encountered the half-icy situation it in the Tesla. I don't want to, so again, I'd like it completely off for bad conditions. Or better, a quad motor EV.


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## El Matadurr (Feb 15, 2019)

ADK46 said:


> Or better, a quad motor EV.


Sounds like the Rivian R1S or R1T is right up you alley.


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## John (Apr 16, 2016)

garsh said:


> Nissan's regen/brake blending with anti-lock is absolutely horrible. As soon as you hit a bump, you lose ALL regen until you take your foot completely off the brake pedal. Additionally, the anti-lock reduces brake force longer than necessary, so the end result is that if you hit a bump going down a steep hill, you immediately start accelerating.
> 
> There's one hill in particular in Pittsburgh that I travel often that is really bad. I've taken my Model 3 on in several times to see how it would handle it. It's been awesome. I could barely even tell that I hit a bump. The anti-lock seems to be ridiculously quick, and gets right back onto full braking. If I pay attention to the screen, I'll see a sharp decrease in regen, which comes right back to full in a fraction of a second. It's so quick that I don't even notice that it had dropped out other than the display of the regen bar on the screen.


I think the most underappreciated thing about Tesla (and TSLA) is that the value in cars-like every other industry-is rapidly shifting to software (nav, braking, communications, remote control, monitoring, driving, customization, upgrades, integration).

And if trad automakers do one thing worst of all, it's software. So, so, so badly.

Audi's software-just to pick out one example-is so angry-making that it would make a bishop kick out a stain glass window. I have tried to help a friend adjust something in their new Audi and just eventually given up. And I don't give up.

When I demoed the I-PACE, I was amazed that in that modern mostly-glass UI there were three different, separate displays with certain options that were covered redundantly by a couple, and certain options which were buried in old-style obscurely-named hierarchical menus in just one. And the sales rep had no better clue than I where each setting lived. Just a crazy funhouse mish-mash of cobbled-together stuff. Argghh.


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