It doesn't make sense

[ctenidae]

you can go 2-3x or more further coasting than regen before stopping depending how hard you set regen. friction brakes activate only with hard braking. your mme will give you a score on how well you brake. im usually at 100% for regen with brakes

But why would you want or need to go 2-3x further? Makes no sense.

I get 98% and 99% all the time, in 1PD Unbridled. I touch the brakes mostly never. Maybe I have more experience driving an EV and do a better job of it. YMMV.

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[Mach1E]

All of this is going to make my head explode. WHISPER, TRY WHISPER.

Lol I wonder if you should tap your microphone to find out if it’s still on…….

I use whisper on the highway (GTPE softest ride), but yeah, it should accomplish the same goal.

Let off the accelerator in whisper and there is no regen.

Whisper mode plus intelligent cruise should result in the same thing people are discussing. I don’t think it’s anything special nor unique.

 

[Socalsp3]

But why would you want or need to go 2-3x further? Makes no sense.

I get 98% and 99% all the time, in 1PD Unbridled. I touch the brakes mostly never. Maybe I have more experience driving an EV and do a better job of it. YMMV.

 

[Socalsp3]

Lol I wonder if you should tap your microphone to find out if it’s still on…….

I use whisper on the highway (GTPE softest ride), but yeah, it should accomplish the same goal.

Let off the accelerator in whisper and there is no regen.

Whisper mode plus intelligent cruise should result in the same thing people are discussing. I don’t think it’s anything special nor unique.

can't really do adaptive cruise in the city though

 

[daemonic3]

This is physically impossible. If you stop applying motive force, friction slows the car down - it converts kinetic energy into heat. Unless you're in a physical world where that does not hold true, and "coasting" is something other than not applying motive force, it is completely wrong to say that coasting is more efficient. It can not be.

Heat = lost energy. Coasting generates heat through friction. Therefore, coasting is losing energy. Period. Point out where that's wrong.

Hmm. You keep using physics as your argument but you're missing something:

"Coasting" = Natural drag from wind and rotational/rolling resistance. Yes, some will be lost as heat that's why there's lubricants

"Regen" = ADDING the resistance of the generator to the drive belt, which slows the car down more than "coasting", and recaptures ONLY the portion of kinetic energy beyond the existing "coasting" resistance.

It is not EITHER/OR, you physically either are "Coasting" or you are "Coasting+Regen". You cannot eradicate the resistance (wind drag and rotational/rolling) of "Coasting" by applying a generator resistance to the drive belt.

SEPARATE QUESTION: Since we may want to switch off 1PD on freeway, or switch to Whisper to emulate the feeling of "Coasting", does anyone know if Alexa voice commands can change drive modes or toggle 1PD? You know, since we don't have the steering wheel trinkets of the Korean cars...

 

[Mach1E]

can't really do adaptive cruise in the city though

Sure you can. But either way, you can definitely do whisper.

And the system we are comparing to only coasts when there is no traffic, so it would have the same problem in the city.

Bottom line? Whisper would have the same results.

 

[Socalsp3]

Hmm. You keep using physics as your argument but you're missing something:

"Coasting" = Natural drag from wind and rotational/rolling resistance. Yes, some will be lost as heat that's why there's lubricants

"Regen" = ADDING the resistance of the generator to the drive belt, which slows the car down more than "coasting", and recaptures ONLY the portion of kinetic energy beyond the existing "coasting" resistance.

It is not EITHER/OR, you physically either are "Coasting" or you are "Coasting+Regen". You cannot eradicate the resistance (wind drag and rotational/rolling) of "Coasting" by applying a generator resistance to the drive belt.

SEPARATE QUESTION: Since we may want to switch off 1PD on freeway, or switch to Whisper to emulate the feeling of "Coasting", does anyone know if Alexa voice commands can change drive modes or toggle 1PD? You know, since we don't have the steering wheel trinkets of the Korean cars...

Alexa just does infotainment I think.

 

[DYohn]

This thread is wjhy i normally dislike car enthusiast forums. Endless arguments about meaningless details just because something might or might not be better or different or becasue some guy (always a guy) thinks they know something different from everyone else. Who TF cares? Just drive your damn car.

 

[ctenidae]

Hmm. You keep using physics as your argument but you're missing something:

"Coasting" = Natural drag from wind and rotational/rolling resistance. Yes, some will be lost as heat that's why there's lubricants

"Regen" = ADDING the resistance of the generator to the drive belt, which slows the car down more than "coasting", and recaptures ONLY the portion of kinetic energy beyond the existing "coasting" resistance.

It is not EITHER/OR, you physically either are "Coasting" or you are "Coasting+Regen". You cannot eradicate the resistance (wind drag and rotational/rolling) of "Coasting" by applying a generator resistance to the drive belt.

I get that. But how can coasting be "more efficient"? You're slowing down a little with no recovery. If you lift your foot off just enough to slow down at a coasting rate, you won't be engaging in any regen. If you need to slow down more than that, you will be either using regen or friction brakes. If you're using regen, then you needed to slow down more than coasting. If you slow down more than coasting and don't use regen, you're using friction brakes.

If you are slowing down at a coasting rate in 1PD, you aren't using regen. Your efficiency is the same in that scenario. If you are slowing down faster than a coasting rate, you are either increasing efficiency by using regen or decreasing efficiency by using friction brakes. I keep using physics because that's what's involved.

I still don't understand what circumstances would benefit from pure freewheel coasting instead of lifting your right foot a couple of microns. Maybe that's the difficulty in this conversation - the premise for desiring to coast makes no sense to me.

 

[ctenidae]

add regen and you slow down even more. regen doesn't recoup the energy already lost to drag. it only recoups energy lost to friction braking.

But then you're not coasting.

 

[daemonic3]

I get that. But how can coasting be "more efficient"? You're slowing down a little with no recovery. If you lift your foot off just enough to slow down at a coasting rate, you won't be engaging in any regen. If you need to slow down more than that, you will be either using regen or friction brakes. If you're using regen, then you needed to slow down more than coasting. If you slow down more than coasting and don't use regen, you're using friction brakes.

If you are slowing down at a coasting rate in 1PD, you aren't using regen. Your efficiency is the same in that scenario. If you are slowing down faster than a coasting rate, you are either increasing efficiency by using regen or decreasing efficiency by using friction brakes. I keep using physics because that's what's involved.

I still don't understand what circumstances would benefit from pure freewheel coasting instead of lifting your right foot a couple of microns. Maybe that's the difficulty in this conversation - the premise for desiring to coast makes no sense to me.

Again, you are thinking regen resistance is INSTEAD of coasting losses (drag + rolling resistance) but regen resistance is ON TOP OF coasting losses.

Slowing when coasting = Drag + Rolling Resistance
Slowing when doing regen = Drag + Rolling Resistance + Generator Resistance

Drag + Rolling Resistance is the same in both the above equations

If you only want to slow down a little bit, the intrinsic Drag + Rolling Resistance or coasting will do it for you and adding regen on top will slow you down too much AND is a lossy recapture of the kinetic energy.

I don't know how to explain it any clearer. Others have tried too and we seem to be making no progress. If what you are saying was correct, we could all charge our batteries by driving with our right foot riding on the accelerator and left foot riding on the brakes and just charge up because hey, look at all this free kinetic energy!!

 

[Mach1E]

Again, you are thinking regen resistance is INSTEAD of coasting losses (drag + rolling resistance) but regen resistance is ON TOP OF coasting losses.

Slowing when coasting = Drag + Rolling Resistance
Slowing when doing regen = Drag + Rolling Resistance + Generator Resistance

Drag + Rolling Resistance is the same in both the above equations

If you only want to slow down a little bit, the intrinsic Drag + Rolling Resistance or coasting will do it for you and adding regen on top will slow you down too much AND is a lossy recapture of the kinetic energy.

I don't know how to explain it any clearer. Others have tried too and we seem to be making no progress. If what you are saying was correct, we could all charge our batteries by driving with our right foot riding on the accelerator and left foot riding on the brakes and just charge up because hey, look at all this free kinetic energy!!

I think it’s as simple as this:

Regen isn’t 100% efficient at recapturing energy.

Scenario 1: speed up to 100 mph, start the test when you let off the throttle and coast. Measure how far you travel. Measure how much energy is used.

Scenario 2: speed up to 100 mph in 1PD. When you come to a stop, give it throttle so that you travel the same distance as you did in scenario 1.

My bet? Scenario 2 will use more energy to travel the same distance. Why? Because there are energy efficiency losses both in regen and when you have to apply throttle again to travel the distance.

Hint- In scenario 1- the amount of energy used should actually be zero.

Scenario 2- it’s greater than zero.

 

[Kamuelaflyer]

I think it’s as simple as this:

Regen isn’t 100% efficient at recapturing energy.

Scenario 1: speed up to 100 mph, start the test when you let off the throttle and coast. Measure how far you travel. Measure how much energy is used.

Scenario 2: speed up to 100 mph in 1PD. When you come to a stop, give it throttle so that you travel the same distance as you did in scenario 1.

My bet? Scenario 2 will use more energy to travel the same distance. Why? Because there are energy efficiency losses both in regen and when you have to apply throttle again to travel the distance.

Hint- In scenario 1- the amount of energy used should actually be zero.

Scenario 2- it’s greater than zero.

So … when I got my Premium ER AWD, I used to drive in whisper with 1pd off. I take the exact same route each trip to town. 45 miles starting at 4400 feet, climbing to 6000 feet within 3 miles followed by a 9 Mike descent to 1500 ft msl. The remainder is rolling hills trending downwards to sea level. Using whisper and no 1pd that cost me 10 to 11% SOC. When I switched to unbridled and 1pd that same route to tte same place cost me 6% SOC.

Hardly scientific, but I’ll stick with the 1pd and regen.

 

[Socalsp3]

So … when I got my Premium ER AWD, I used to drive in whisper with 1pd off. I take the exact same route each trip to town. 45 miles starting at 4400 feet, climbing to 6000 feet within 3 miles followed by a 9 Mike descent to 1500 ft msl. The remainder is rolling hills trending downwards to sea level. Using whisper and no 1pd that cost me 10 to 11% SOC. When I switched to unbridled and 1pd that same route to tte same place cost me 6% SOC.

Hardly scientific, but I’ll stick with the 1pd and regen.

There are variables in this situation. Did you go down at the same speed? Was there head/wind tail wind? How efficient was your braking? Were the temperatures the same? Was it a curvy path that required slowing and accelerating? Maybe you are really good at coasting in 1 pedal, tricky but possible.

In the end the mode that is most comfortable for you is likely the most efficient for you. A person not good at coasting will likely not be efficient at it.

 

[Kamuelaflyer]

1. No brake coach in unbridled. In engage, I usually get in the high 90’s.
2. 67 mph descending the Daniel K every single time. 55 on the upper highway rollers. Any faster and you’re guaranteed a ticket (particularly on the Daniel K). Any slower and the Dodge Rams enroute to get their ticket out of the way will ram you.
3. Wind is always an onshore breeze when I’m driving that route. Headwinds followed by a right crosswind.
4. These are the consistent numbers from 15 months of driving that route.
5. I generally hit the bottom of the Daniel K , 13 or so miles from home, at tte same soc as when I left. If 1pd is off, it’s usually about 3% down. Both are improvements from the 6000 ft peak elevation SOC which has me at 7%+ down, 3 to 4 miles from home.

it’s all good. Drive the car the way you think is best.

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