Did you know Neutral (N) does this?

[mkhuffman]

I am a regular on the forum, but it is possible I missed someone else posting about this. Link to it if you must!

So the other day, I was driving around town and decided to play around with the drive selector. What would happen if I spun it all the way into Reverse or Park? Actually, nothing really happens except for a warning from the car that it won't engage until you are going slower. But Neutral was a revelation.

If you like to hyper-mile, or get the best range possible, coasting is key. It is possible to approximate coasting using the go-pedal and careful modulation, but really you are just playing around the edges. You are either pressing the pedal too hard or too soft, and the car is not really coasting.

But if you put the car in Neutral, it coasts. The car uses zero energy while in Neutral, just like if you are sitting still. If you time things right, you pop it into Neutral and coast up to the stoplight. Of course it won't slow you down, so you either need to press the brake pedal or flip it into Drive to slow the car (using 1PD). I do the latter because I know 1PD is using the motor not the brakes, so I get the best regen possible.

Here is a graph that shows how coasting compares to sitting still. It is exactly the same. So the more time you spend coasting, the less energy you use.

Does it actually improve your efficiency to coast? I think it absolutely does. The challenge is knowing when to coast. Since it uses no energy to coast, if you are going up a hill, you will slow down pretty quickly. If you are in a flat area, you will slow down but not as quickly. Of course you may pick up speed when going down a hill. It takes practice and timing to really get it right.

One thing is for sure at least for me: you don't want to do this with passengers in the car. It is almost impossible to make all the transitions from coasting to Drive smoothly. Some are great and you can't even feel it. Others are rough. I suppose with a lot of practice you can get the transitions to be mostly smooth. It is much easier to drive smoothly by just keeping it in Drive.

Here is a 5.2 mile trip in 50 F weather (not cold) with no heat being used. At that temperature, I often turn off the climate because the car is sufficiently warm inside, especially because I start my drive in the warmer than outside garage.

Starting battery = 67.57 kWh
Ending battery = 66.25
Total battery used = 1.32 kWh
Distance traveled = 5.2 miles
Efficiency = 5.2 / 1.32 = 3.9 mi/kWh

Pretty excellent. Of course there are many variables, and I didn't repeat the trip without using Neutral coasting. I think though, that for a GT, it is about as good as it gets.

The trip was in town, multiple stop lights, and max speed around 45 mph during a one mile stretch. It is definitely a highly efficient route which I would have done well without coasting, but still. I think the coasting helped.

 

[Mach1E]

I am a regular on the forum, but it is possible I missed someone else posting about this. Link to it if you must!

So the other day, I was driving around town and decided to play around with the drive selector. What would happen if I spun it all the way into Reverse or Park? Actually, nothing really happens except for a warning from the car that it won't engage until you are going slower. But Neutral was a revelation.

If you like to hyper-mile, or get the best range possible, coasting is key. It is possible to approximate coasting using the go-pedal and careful modulation, but really you are just playing around the edges. You are either pressing the pedal too hard or too soft, and the car is not really coasting.

But if you put the car in Neutral, it coasts. The car uses zero energy while in Neutral, just like if you are sitting still. If you time things right, you pop it into Neutral and coast up to the stoplight. Of course it won't slow you down, so you either need to press the brake pedal or flip it into Drive to slow the car (using 1PD). I do the latter because I know 1PD is using the motor not the brakes, so I get the best regen possible.

Here is a graph that shows how coasting compares to sitting still. It is exactly the same. So the more time you spend coasting, the less energy you use.

Does it actually improve your efficiency to coast? I think it absolutely does. The challenge is knowing when to coast. Since it uses no energy to coast, if you are going up a hill, you will slow down pretty quickly. If you are in a flat area, you will slow down but not as quickly. Of course you may pick up speed when going down a hill. It takes practice and timing to really get it right.

One thing is for sure at least for me: you don't want to do this with passengers in the car. It is almost impossible to make all the transitions from coasting to Drive smoothly. Some are great and you can't even feel it. Others are rough. I suppose with a lot of practice you can get the transitions to be mostly smooth. It is much easier to drive smoothly by just keeping it in Drive.

Here is a 5.2 mile trip in 50 F weather (not cold) with no heat being used. At that temperature, I often turn off the climate because the car is sufficiently warm inside, especially because I start my drive in the warmer than outside garage.

Starting battery = 67.57 kWh
Ending battery = 66.25
Total battery used = 1.32 kWh
Distance traveled = 5.2 miles
Efficiency = 5.2 / 1.32 = 3.9 mi/kWh

Pretty excellent. Of course there are many variables, and I didn't repeat the trip without using Neutral coasting. I think though, that for a GT, it is about as good as it gets.

The trip was in town, multiple stop lights, and max speed around 45 mph during a one mile stretch. It is definitely a highly efficient route which I would have done well without coasting, but still. I think the coasting helped.

That’s pretty cool, but a ton of work to do what whisper does already (coasts).

Whisper (per the power meter in the GT) does no regen.

 

[macchiaz-o]

If I'm understand this correctly, by using Neutral, you are reducing some energy usage at the expense of maintaining desired speed.

In other words, while your car is in Neutral, it may be speeding up or slowing down depending on the grade, and you are only doing it because the situation around you (other vehicles, speed limits, etc) allows you that flexibility. Right?

In my normal daily driving through the suburbs, I can't think of anytime where I'd do this. Maybe in a more rural area?

 

[mkhuffman]

That’s pretty cool, but a ton of work to do what whisper does already (coasts).

Whisper (per the power meter in the GT) does no regen.

Maybe you could use Whisper and "L" to slow the car and get a similar result. I was using the 1PD slowing from Unbridled in Drive.

 

[Murse-In-Airy]

Interesting stuff Mike.
I might have to try it when I go to work on Wednesday and see what I can accomplish.

 

[Mach1E]

Maybe you could use Whisper and "L" to slow the car and get a similar result. I was using the 1PD slowing from Unbridled in Drive.

Yes.

But if you want to coast, turn off 1pd and use whisper. No need to neutral.

And L and 1PD are different. L won’t bring you to a complete stop.

 

[mkhuffman]

If I'm understand this correctly, by using Neutral, you are reducing some energy usage at the expense of maintaining desired speed.

In other words, while your car is in Neutral, it may be speeding up or slowing down depending on the grade, and you are only doing it because the situation around you (other vehicles, speed limits, etc) allows you that flexibility. Right?

In my normal daily driving through the suburbs, I can't think of anytime where I'd do this. Maybe in a more rural area?

The traffic in Williamsburg is not bad except for our rush hour, which is really just an hour. Seriously. Anyway, it is about timing. You can be following someone on a slight downgrade, and pop it into Neutral., coasting along behind. Neutral never really works going up a hill, unless you are coming up on a stop or a light and need to slow anyway. If the traffic is abruptly changing speeds, it will be hard to use. You have to anticipate and judge based on the terrain.

I am up in the DC area frequently and will try Neutral driving up there also. I don't think it will be much more of a challenge even though traffic is worse.

 

[mkhuffman]

Yes.

But if you want to coast, turn off 1pd and use whisper. No need to neutral.

And L and 1PD are different. L won’t bring you to a complete stop.

Yeah, but I don't like Whisper. I like how 1PD stops the car without me needing to use the brake. I can engage 1PD by flipping the selector into Drive, and stop the car without even touching a pedal.

 

[Motomax]

This isn’t a Prius, get out of here with your hyper-miling lol. I hope you don’t also drive 40mph of the freeway lol.
Btw, all modern cars work that way with the reverse gear (possibly even the parking pawl). Even a manual won’t go into reverse, it’ll just happily grind away lol.

 

[TargaGone]

I don't think I have read yet in this thread why coasting is more efficient than regeneration. Maybe I am the only one proposing a clarification that is clear from other discussions. Regeneration, although more efficient than braking, does require current flow and other losses. It is not 100% efficient - how efficient is regeneration?

I have found One Pedal driving to be intuitive, perhaps from years, hell-decades, of manual transmission driving. I like knowing that no rotor warmth is occurring thus improving mi/watt. HOWEVER, those rotors do need some action every now and then to smooth out use, especially at stop-starts. The opportunity to buff my rotors presents itself when descending a >4% grade and shifting to Neutral - I find that this is the best way to guarantee some rotor action.

 

[hawkeye3point1]

Of course you may pick up speed when going down a hill. It takes practice and timing to really get it right.

Whisper has the advantage of baked-in variable regen to keep speed from increasing by more than 5 mph or so downhill, regardless of how steep.

I do agree that using the inertia of 2 1/2 ton vehicle is efficient and typically see 300 - 500 watts on the power meter with no go pedal, which is baseline key-on power consumption of the MME.

Selecting Low essentially engages 1P in Whisper. Did that at first, but find that using the brake pedal is easier to gauge decel rate to the situation and does not sacrifice regen.

As always, to each his own.

 

[Scooby24]

This mirrors my experience using Whisper mode vs engage or unbridled. Whisper is effectively coasting unless you pick up speed going downhill in which case regen kicks in to try and keep you from picking up too much speed. I see quite a significant impact in that alone as, like you said, trying to modulate the throttle right on the edge of accel or regen is just...too hard to get right.

 

[Mach1E]

Yeah, but I don't like Whisper. I like how 1PD stops the car without me needing to use the brake. I can engage 1PD by flipping the selector into Drive, and stop the car without even touching a pedal.

Even though this is a fun experiment, I 100% don’t recommend it as a regular practice, for a few reasons:

1. It’s dangerous. Going in and out of gear takes your attention away from the road. You also may have a situation where you NEED to accelerate to avoid a crash and won’t be able to in neutral or may not react fast enough putting it on drive.

2. People have tested all combinations of drive modes. And there is no winner. How you drive (speed, acceleration and braking) determine efficiency, not the drive mode.

Summary- more dangerous and not any more efficient.

 

[alexgorod]

Even though this is a fun experiment, I 100% don’t recommend it as a regular practice, for a few reasons:

1. It’s dangerous. Going in and out of gear takes your attention away from the road. You also may have a situation where you NEED to accelerate to avoid a crash and won’t be able to in neutral or may not react fast enough putting it on drive.

When I learned how to drive many years ago in a galaxy far, far away, in a car with a stick shift, I was told not to coast on neutral and always have the engine connected to the wheels for pretty much the same reason.

Yes, sometimes there is a situation when one needs to save every possible drop of gas or watt of electrical power in the battery. Neutral can help in this situation. But if it's used as a regular practice - there is nothing more "not a mustang" thing to drive this car and trying to make an efficiency record, there are Priuses for that as I've heard.

 

[Logal727]

I am a regular on the forum, but it is possible I missed someone else posting about this. Link to it if you must!

So the other day, I was driving around town and decided to play around with the drive selector. What would happen if I spun it all the way into Reverse or Park? Actually, nothing really happens except for a warning from the car that it won't engage until you are going slower. But Neutral was a revelation.

If you like to hyper-mile, or get the best range possible, coasting is key. It is possible to approximate coasting using the go-pedal and careful modulation, but really you are just playing around the edges. You are either pressing the pedal too hard or too soft, and the car is not really coasting.

But if you put the car in Neutral, it coasts. The car uses zero energy while in Neutral, just like if you are sitting still. If you time things right, you pop it into Neutral and coast up to the stoplight. Of course it won't slow you down, so you either need to press the brake pedal or flip it into Drive to slow the car (using 1PD). I do the latter because I know 1PD is using the motor not the brakes, so I get the best regen possible.

Here is a graph that shows how coasting compares to sitting still. It is exactly the same. So the more time you spend coasting, the less energy you use.

Does it actually improve your efficiency to coast? I think it absolutely does. The challenge is knowing when to coast. Since it uses no energy to coast, if you are going up a hill, you will slow down pretty quickly. If you are in a flat area, you will slow down but not as quickly. Of course you may pick up speed when going down a hill. It takes practice and timing to really get it right.

One thing is for sure at least for me: you don't want to do this with passengers in the car. It is almost impossible to make all the transitions from coasting to Drive smoothly. Some are great and you can't even feel it. Others are rough. I suppose with a lot of practice you can get the transitions to be mostly smooth. It is much easier to drive smoothly by just keeping it in Drive.

Here is a 5.2 mile trip in 50 F weather (not cold) with no heat being used. At that temperature, I often turn off the climate because the car is sufficiently warm inside, especially because I start my drive in the warmer than outside garage.

Starting battery = 67.57 kWh
Ending battery = 66.25
Total battery used = 1.32 kWh
Distance traveled = 5.2 miles
Efficiency = 5.2 / 1.32 = 3.9 mi/kWh

Pretty excellent. Of course there are many variables, and I didn't repeat the trip without using Neutral coasting. I think though, that for a GT, it is about as good as it gets.

The trip was in town, multiple stop lights, and max speed around 45 mph during a one mile stretch. It is definitely a highly efficient route which I would have done well without coasting, but still. I think the coasting helped.

I dunno, this sounds like a lot of work for this car, feel like it might invite some gremlins, probably unfounded but still lol.