Shift Selector??

[Norton]

How does it work with Park being between D and N -- R?

Do you have to come to a complete stop anytime you shift from D to R and R to D?

I like not having to do that in EV's and some Hybrids.

 

[stevewa]

How does it work with Park being between D and N -- R?

Do you have to come to a complete stop anytime you shift from D to R and R to D?

I like not having to do that in EV's and some Hybrids.

When Ford hosted an event in Michigan after the release of the Escape Hybrid, one of the things they did was have the driver proceed forward at 40MPH then throw the shifter into reverse...since it's just software, nothing happens!

Is park not a button? I know one of Consumer Reports few gripes about their quick drive in the Bolt was the "parts bin" shifter.

 

[EldRick]

Right - Park is a button at the top of the shifter, that puts you into park from any other "gear", and turns on the Park light.

 

[SeanNelson]

How does it work with Park being between D and N -- R?

I'm wondering about "Neutral". I sometimes like to shift into Neutral to be able to truly coast without using any power or inadvertendly losing any speed due to regen. But on the Bolt shifter it looks like you have to go through "Park" in order to get from "D" to "N". Is it actually possible to shift between "N" and "D" while moving?

 

[CGameProgrammer]

I don't think you can actually shift into Park; you have to either push the button or turn off the car. Pushing the selector forward goes into neutral. By the way you can shift from reverse to drive while still moving backwards, and vice versa, but only if your speed is fairly low. I agree it's a nice feature and I do it all the time in my previous manual-transmission car.

 

[roundpeg]

I don't think you can actually shift into Park; you have to either push the button or turn off the car. Pushing the selector forward goes into neutral. By the way you can shift from reverse to drive while still moving backwards, and vice versa, but only if your speed is fairly low. I agree it's a nice feature and I do it all the time in my previous manual-transmission car.

That is correct. Park is not a position on the shifter, it's activated by the button on the top of the shifter. This device is my biggest quibble with the Bolt thus far. The method for shifting in and especially out of R is especially puzzling. It can be managed but it is functionally far from intuitive.

I am new to EVs but can't see any benefit to shifting to Neutral for rolling. On the Bolt if you prefer that sensation they've provided the D position.

 

[WetEV]

I am new to EVs but can't see any benefit to shifting to Neutral for rolling. On the Bolt if you prefer that sensation they've provided the D position.

Hypermiling. Not for the sensation, but for minimum energy use.

http://www.mynissanleaf.com/viewtopic.php?f=27&t=5508

See item 6, and others. I usually don't hypermile, but I've learned how to for times when I might want/need to do it.

 

[roundpeg]

Hypermiling. Not for the sensation, but for minimum energy use.

http://www.mynissanleaf.com/viewtopic.php?f=27&t=5508

See item 6, and others. I usually don't hypermile, but I've learned how to for times when I might want/need to do it.

I've been using these techniques for ages especially with a manual shifter. In the conventional engine case you get little benefit from engine braking except saving on brake wear. So I am a skeptic when it comes to the benefits of shifting to neutral on an EV to coast, rather than allowing the car to recapture energy, as it was designed to do.

Since starting to drive the Bolt I've found in the L setting that timing a stop to maximize regeneration isn't a very difficult technique to master. If I understand what the car is doing you are maximizing energy conservation when the car comes to a full stop without touching the brake pedal. Otherwise you are maximizing conservation by maintaining a steady rate of speed (that's just physics), and the slower the better (laws of thermodynamics?).

 

[WetEV]

Otherwise you are maximizing conservation by maintaining a steady rate of speed (that's just physics), and the slower the better (laws of thermodynamics?).

Coasting down is better than regeneration mixed with acceleration, as the round trip loss is around 30%.

Consider a traffic light that is traffic triggered. You need to stop for a bit before it turns green. An energy wasting high loss way would be to drive at a steady speed, then slam on the friction brakes to stop, wasting 100% of kinetic energy. A lower loss way would be to drive at a steady speed, then put some of kinetic energy into the batteries, then resume. The slower the stop, the more of the energy is recovered. An even low loss way would be to use the kinetic energy to propel the car as it gradually coasts almost to a stop, then use a bit of regeneration to complete the stop.

Regeneration energy recovery depends on rate. Suppose you are going down a slope. If the slope is exactly the correct one, you will coast at your expected speed. 100% of your potential energy is being used to overcome drag losses. If the slope is steeper, and you recover energy with regeneration, you charge the battery at rate "I" amps, the power lost charging is more than I^2 (current squared). The higher the regeneration rate, the more the power loss. Same on acceleration, the lower the power used the less energy is wasted.

If you are ok with 3 miles per kWh, ignore all this. If you are ok with 4 miles per kWh, watch speed and avoid using friction brakes. If you are ok with 5 miles per kWh, minimize both power used and regeneration used. If you want 6 miles per kWh, you are crazy, but it's doable on warm days, flat roads and light traffic. Record as far as I know (in a Leaf) is 8.8 miles per kWh.


Air drag dominates above a fairly slow speed (10mph to 20mph), and is roughly proportional to speed squared. 60mph is roughly 9 times the energy used per mile relative to 20 mph.

 

[roundpeg]

Yes, not changing speeds is the most energy efficient. That's just Newton's First Law and it applies to everything. Keeping the speed down is also more efficient. The laws of thermodynamics. Totally agree.

However, the question here (I thought) was whether it makes sense to "coast down" in neutral on an EV, or allow it to recapture energy through regeneration. I don't see the case for neutral. For discussion purposes don't add slopes. Assume flat terrain.

 

[phil0909]

How does it work with Park being between D and N -- R?

I'm wondering about "Neutral". I sometimes like to shift into Neutral to be able to truly coast without using any power or inadvertendly losing any speed due to regen. But on the Bolt shifter it looks like you have to go through "Park" in order to get from "D" to "N". Is it actually possible to shift between "N" and "D" while moving?

Yes. The Owner's Manual says this, on p202 under the heading of "Stopping the vehicle...":

"2. Shift the vehicle to N (Neutral).
This can be done while the
vehicle is moving. After shifting
to N (Neutral), firmly apply the
brakes and steer the vehicle to
a safe location."

However, it appears the Bolt prefers coasting be done thru "1-pedal driving", i.e. exactly the right amount of depression of the accelerator. The manual also says this, on p30:

"Do not shift to N (Neutral) to coast.
The vehicle recovers energy while
coasting and braking in D (Drive)
or L (Low)."

There's also this, on p207:

"Caution
The vehicle is not designed to
stay in N (Neutral) for extended
periods of time. It will
automatically shift into P (Park)"

I also like to use N occasionally, but it looks like I'll need to learn to do things differently.

 

[CGameProgrammer]

Neutral is required by law so of course the car will have it. In a regular car neutral actually uses gas to keep the engine idling, but in gear the vehicle's motion handles that and no gas is used. However in an electric car neutral is actually viable and efficient. That said, the regen of D is quite minor so I probably won't use neutral.

Reverse is easier to shift into than with a manual so I think the complainers are just babies. But what's nice is that you shift from reverse to D with a quick pull of the lever, without needing to push any button. So it's really fast.

 

[SeanNelson]

So I am a skeptic when it comes to the benefits of shifting to neutral on an EV to coast, rather than allowing the car to recapture energy, as it was designed to do.

You don't want the car to recapture energy unless you need to slow down. If you don't want to slow down then coasting in neutral is the best guarantee that you're not loosing momentum to regen nor loosing battery power to propulsion. Of course you're going to loose momentum due to air resistance and other frictional loses, but that's basically the best you can do.

That isn't something I do a whole lot of, but on the occasions where I'd like to do it it's nice to know that it's possible.

 

[SeanNelson]

How does it work with Park being between D and N -- R?

I'm wondering about "Neutral". I sometimes like to shift into Neutral to be able to truly coast without using any power or inadvertendly losing any speed due to regen. But on the Bolt shifter it looks like you have to go through "Park" in order to get from "D" to "N". Is it actually possible to shift between "N" and "D" while moving?

Yes. The Owner's Manual says this, on p202 under the heading of "Stopping the vehicle...":

"2. Shift the vehicle to N (Neutral).
This can be done while the
vehicle is moving. After shifting
to N (Neutral), firmly apply the
brakes and steer the vehicle to
a safe location."

Thanks for the clarification. I think the location of that "P" on the shifter is a pretty stupid design decision. It would be far more intuitive if they just put the lighted indicator in the "P" button.

 

[EldRick]

I think the location of that "P" on the shifter is a pretty stupid design decision. It would be far more intuitive if they just put the lighted indicator in the "P" button.

Totally agree. What on earth were they thinking?

 

[CGameProgrammer]

Agreed, it is very misleading.