Driving in 'L' mode

[oilerlord]

The button behind the steering wheel adds another option to use heavy regen braking in either mode. The sport mode button presumably remaps the accelerator input so that a light press indicates a higher level of desired acceleration than in non-sport mode.

...Which to me sound more like gimmicks when EV's already have brake pedals that modulate regen. Is there a difference between touching the brake or using the paddle? I've read complaints that the paddle regen is too binary, and can't be modulated, so I must be missing some other benefit for the reason it's there.

I don't fault GM or other manufacturers for having regen paddles, and a host of different regen modes, because it's apparently something EV buyers want them to have.

 

[phil0909]

Is there a difference between touching the brake or using the paddle?

Yes. With the paddle, you can be sure you are using regen only. If you use the brake pedal and depress it too far, you may use a bit of friction.

I wouldn't care, but a hypermiler would. I imagine the paddle is for them. I use it anyway, because why not? Of course, I'm always ready to apply the brakes if needed.

 

[michael]

The button behind the steering wheel adds another option to use heavy regen braking in either mode. The sport mode button presumably remaps the accelerator input so that a light press indicates a higher level of desired acceleration than in non-sport mode.

...Which to me sound more like gimmicks when EV's already have brake pedals that modulate regen. Is there a difference between touching the brake or using the paddle? I've read complaints that the paddle regen is too binary, and can't be modulated, so I must be missing some other benefit for the reason it's there.

I don't fault GM or other manufacturers for having regen paddles, and a host of different regen modes, because it's apparently something EV buyers want them to have.

I so agree with you. I am completely comfortable using the brake pedal as my "extra regen" control. It works great for me.

Both my Focus and my Volt work that way...I'm completely satisfied.

On the Focus, the brake pedal is completely a "brake by wire" system. Except in the emergency case where the normal brake function has failed, the pedal is simply a control that instructs the system first to use regen and then to use friction brakes. It really is no different than the paddle except that friction braking is available if desired.

 

[oilerlord]

I wouldn't care, but a hypermiler would. I imagine the paddle is for them. I use it anyway, because why not?

As a recovering hypermiling addict...I don't believe that's the case. One pedal driving makes hypermiling easy, though extreme hypermilers (the guys that take their shoes off to get a better "feel" for the pedals) are looking for that extra 1% wherever they can get it. From experience, true hypermilers would prefer a freewheel coast mode, and only use the brake pedal when necessary (hypermilers believe ALL braking is bad, regen or otherwise). The regen paddles are too binary, and come on way too strong. GM did mention they installed the paddles for hypermilers but their focus group got that one wrong.

 

[phil0909]

I wouldn't care, but a hypermiler would. I imagine the paddle is for them. I use it anyway, because why not?

As a recovering hypermiling addict...I don't believe that's the case. One pedal driving makes hypermiling easy, though extreme hypermilers (the guys that take their shoes off to get a better "feel" for the pedals) are looking for that extra 1% wherever they can get it. From experience, true hypermilers would prefer a freewheel coast mode, and only use the brake pedal when necessary (hypermilers believe ALL braking is bad, regen or otherwise). The regen paddles are too binary, and come on way too strong. GM did mention they installed the paddles for hypermilers but their focus group got that one wrong.

I did not say the paddle is the best solution for the hypermilers, I said it's the one Chevy provided. I agree that a neutral coast option would be better.

 

[gpsman]

Hey-

Have the rest of you guys noticed a definate change in performance when holding the foot pedal perfectly still and shifting from D to L and vice versa?

What I mean is:

If I am holding the pedal perfectly still in D to maintain a steady 55 mph on the freeway, and shift to L, the regen goes on and I immediately slow down, requiring a shift in foot position (more down) to maintain 55 mph.

The reverse is also true. Crusing at a constant 55 mph in L and shifting to D makes the car immediately speed up.

It shouldn't work like this. L should only affect slowing. It shouldn't affect going. If you think your car does not do this, please go out and deliberately try it. You may have overlooked it or never done this.

My 2005 Hybrid does not do this, and the technology is ancient compared to a Bolt EV.

 

[LeftieBiker]

Hey-

Have the rest of you guys noticed a definate change in performance when holding the foot pedal perfectly still and shifting from D to L and vice versa?

What I mean is:

If I am holding the pedal perfectly still in D to maintain a steady 55 mph on the freeway, and shift to L, the regen goes on and I immediately slow down, requiring a shift in foot position (more down) to maintain 55 mph.

The reverse is also true. Crusing at a constant 55 mph in L and shifting to D makes the car immediately speed up.

It shouldn't work like this. L should only affect slowing. It shouldn't affect going. If you think your car does not do this, please go out and deliberately try it. You may have overlooked it or never done this.

My 2005 Hybrid does not do this, and the technology is ancient compared to a Bolt EV.

It's the same with the Leaf. Changing modes speeds or slows the car, even with a steady foot.

 

[SeanNelson]

If I am holding the pedal perfectly still in D to maintain a steady 55 mph on the freeway, and shift to L, the regen goes on and I immediately slow down, requiring a shift in foot position (more down) to maintain 55 mph.

I don't own a Bolt, but it seems pretty obvious to me that this would be the case. In "D" mode there's only a small range at the top of pedal travel where power isn't being applied and the car slows in a way that simulates what happens when you take your foot off the gas pedal in an ICE vehicle. So the "neutral point" where you're neither accelerating nor decelerating In "L" mode is pretty close to the top of the range.

In "D" mode, the "neutral point" requires more push of the pedal. That's so that you have a range of pedal travel above the neutral point to modulate how much deceleration you get from the increased regen.

For sake of argument, let's say that the "D" neutral point is with the pedal depressed 1 inch, and the "L" neutral point is with the pedal depressed 3 inches. If you're driving in "D" with the pedal depressed 2 inches, you're 1 inch into the "power" range - but if you switch into "L" mode you're suddenly 1 inch into the "braking" range, and you have to press the pedal down further to get past this mode's neutral point in order to apply power.

 

[boltage]

Have the rest of you guys noticed a definate change in performance when holding the foot pedal perfectly still and shifting from D to L and vice versa?

What I mean is:

If I am holding the pedal perfectly still in D to maintain a steady 55 mph on the freeway, and shift to L, the regen goes on and I immediately slow down, requiring a shift in foot position (more down) to maintain 55 mph.

The reverse is also true. Crusing at a constant 55 mph in L and shifting to D makes the car immediately speed up.

That looks like it would be the expected behavior, since D versus L is merely a remapping of how accelerator and brake pedal affect power delivery or regeneration. See http://www.mychevybolt.com/forum/viewtopic.php?f=21&t=5905&start=10#p17104 .

 

[Zago]

Hey gpsman,

Try holding the pedal steady at 55mph and hit the sport button, you will get a totally different response, instead of slowing down, the car will speed up, it is just the way the throttle mapping was engineered.

cheers.

 

[LeftieBiker]

The Leaf has an unfortunate button arrangement that comes into play here. The Cruise button is above and close to the Eco button, so if you are driving in Eco and blindly try to switch cruise control on, you often end up switching to D instead, with the car lunging forward as the pedal remaps.

 

[ChevyCustomerCare]

...decelerating greater than approximately 0.10g. This can occur while using the regen paddle, driving in "L" Mode or both.

Thanks for the info, Amber.

Can regen torque produce the necessary 0.10g deceleration in "D" mode? At highway speeds, D can produce substantial regeneration. It would be helpful to confirm that the brake lights are never activated by regen in D.

Also, how does the Bolt inform the driver that regen torque deceleration has exceeded approximately .10g and activated the brake lights? I have not found any accelerometer reading or brake light indicator on the dashboard.

Your assistance is appreciated.

Hi phil0909,

Our apologies for the delay in response! We have been working with our internal team to gather some insight for you. They confirmed that the regen level in D will not activate the brake lights, even at highway speeds. In regards to your second question, there is no accelerometer on the instrument panel to display vehicle acceleration.

We hope this information helps. If you have any other questions, please don't hesitate to let us know!

Lauren E.
Chevrolet Customer Care

 

[phil0909]

Hi phil0909,

Our apologies for the delay in response! We have been working with our internal team to gather some insight for you. They confirmed that the regen level in D will not activate the brake lights, even at highway speeds. In regards to your second question, there is no accelerometer on the instrument panel to display vehicle acceleration.

We hope this information helps. If you have any other questions, please don't hesitate to let us know!

Lauren E.
Chevrolet Customer Care

Thanks Lauren. Although the answer is a little disappointing, I really appreciate your looking into it and providing the answer.

I think it's confusing for customers to have brake lights controlled automatically based on an obscure, unreported parameter like acceleration measured in g! If you're going to use acceleration level to control the lights, it would be desirable to report that to the driver. Or just provide a dashboard indicator telling us whether brake lights are currently on or off.

Negative 0.1g of acceleration works out to about 2.2 mph of deceleration in a second. I've never thought much about cars and g's, but that seems like a pretty mild deceleration will trigger the brake lights. I'm thinking in practice this will usually result in brake lights being "on" at any time my foot is completely off the accelerator pedal while the car is in motion and in L (i.e. brake lights turn off just as the car comes to a complete stop), and regardless of the regen paddle on the steering wheel. The only exception I can think of is coasting down a steepish hill in L, which might produce zero g's of deceleration. Anyone think otherwise? Maybe someday when I have a lot of time on my hands, I'll put a stopwatch on the speedometer and check that out.

Thanks again, Lauren.

 

[Anonymous]

I'm having an issue and am hoping the Chevy folks might have some advice. I've been driving my Bolt for 3 weeks (outstanding car, by the way) and prefer driving in L mode. The problem I'm having is that it works well 90% of the time, but the regeneration just doesn't kick in (or kicks in VERY weakly) about 10% of the time. Now I drive the same route every day. Approaching the same stop sign at the same speed and lifting my foot at the same time sometimes fails to properly engage the regenerative braking. When this happen, depressing the steering wheel paddle also has no effect. Now this is happening on a dry, level road with no disruptions like a manhole cover to trigger the traction control. Under exactly the same conditions in L, it usually brakes nicely to a complete stop, yet sometimes it simply won't stop without my depressing the brake pedal. I'm sure my Colorado dealer's service department has little experience yet with the Bolt, and getting an intermittent problem diagnosed is always a challenge even with experienced service technicians. Any thoughts on what might be causing this? Has anyone else experienced this erratic behavior with one-pedal driving?

 

[JeffN]

I'm having an issue and am hoping the Chevy folks might have some advice. I've been driving my Bolt for 3 weeks (outstanding car, by the way) and prefer driving in L mode. The problem I'm having is that it works well 90% of the time, but the regeneration just doesn't kick in (or kicks in VERY weakly) about 10% of the time. Now I drive the same route every day. Approaching the same stop sign at the same speed and lifting my foot at the same time sometimes fails to properly engage the regenerative braking. When this happen, depressing the steering wheel paddle also has no effect. Now this is happening on a dry, level road with no disruptions like a manhole cover to trigger the traction control. Under exactly the same conditions in L, it usually brakes nicely to a complete stop, yet sometimes it simply won't stop without my depressing the brake pedal. I'm sure my Colorado dealer's service department has little experience yet with the Bolt, and getting an intermittent problem diagnosed is always a challenge even with experienced service technicians. Any thoughts on what might be causing this? Has anyone else experienced this erratic behavior with one-pedal driving?

This is likely because regeneration is generally minimal or disabled due to either having a nearly 100% full battery or having a cold battery that's been sitting in an unheated area overnight. Cold batteries aren't allowed to charge rapidly.

When this happens you should see that the regen symbol on the right side of the driver display screen is grey. When the symbol is green it indicates that regeneration is enabled.

If you determine that this is happening due to a nearly full battery you might enable Hill Reserve mode on the charge option setting center screen. Doing that will limit the battery charge to around 88-90% instead of fully topping off to 100%. This will enable full regeration ability even when immediately driving downhill after a charge.

 

[Anonymous]

Thank you. I noticed this again today. The battery was full. The regen worked on some stops and not on others so it was erratic, but your explanation makes sense. I'll try what you suggest and also see if this erratic behavior still occurs with a partially charged battery.

 

[user 387]

Hilltop mode for the win. In addition to regen advantages, it may lead to longer battery life over the long haul.

 

[Posatronic]

I'm having an issue and am hoping the Chevy folks might have some advice. I've been driving my Bolt for 3 weeks (outstanding car, by the way) and prefer driving in L mode. The problem I'm having is that it works well 90% of the time, but the regeneration just doesn't kick in (or kicks in VERY weakly) about 10% of the time. Now I drive the same route every day. Approaching the same stop sign at the same speed and lifting my foot at the same time sometimes fails to properly engage the regenerative braking. When this happen, depressing the steering wheel paddle also has no effect. Now this is happening on a dry, level road with no disruptions like a manhole cover to trigger the traction control. Under exactly the same conditions in L, it usually brakes nicely to a complete stop, yet sometimes it simply won't stop without my depressing the brake pedal. I'm sure my Colorado dealer's service department has little experience yet with the Bolt, and getting an intermittent problem diagnosed is always a challenge even with experienced service technicians. Any thoughts on what might be causing this? Has anyone else experienced this erratic behavior with one-pedal driving?

This is likely because regeneration is generally minimal or disabled due to either having a nearly 100% full battery or having a cold battery that's been sitting in an unheated area overnight. Cold batteries aren't allowed to charge rapidly.

When this happens you should see that the regen symbol on the right side of the driver display screen is grey. When the symbol is green it indicates that regeneration is enabled.

If you determine that this is happening due to a nearly full battery you might enable Hill Reserve mode on the charge option setting center screen. Doing that will limit the battery charge to around 88-90% instead of fully topping off to 100%. This will enable full regeration ability even when immediately driving downhill after a charge.

This is close but not completely accurate. It will regen when the regen is greyed out. But it is REDUCED. If you look their is a bar on the regen part that gives you he max regen when fully charged and or cold. It has never been zero. It has been as low as zero degrees also. The rest is correct. Minor correction but I felt it was nessary to point out. Enjoy.

 

[ChevyCustomerCare]

Hi phil0909,

Our apologies for the delay in response! We have been working with our internal team to gather some insight for you. They confirmed that the regen level in D will not activate the brake lights, even at highway speeds. In regards to your second question, there is no accelerometer on the instrument panel to display vehicle acceleration.

We hope this information helps. If you have any other questions, please don't hesitate to let us know!

Lauren E.
Chevrolet Customer Care

Thanks Lauren. Although the answer is a little disappointing, I really appreciate your looking into it and providing the answer.

I think it's confusing for customers to have brake lights controlled automatically based on an obscure, unreported parameter like acceleration measured in g! If you're going to use acceleration level to control the lights, it would be desirable to report that to the driver. Or just provide a dashboard indicator telling us whether brake lights are currently on or off.

Negative 0.1g of acceleration works out to about 2.2 mph of deceleration in a second. I've never thought much about cars and g's, but that seems like a pretty mild deceleration will trigger the brake lights. I'm thinking in practice this will usually result in brake lights being "on" at any time my foot is completely off the accelerator pedal while the car is in motion and in L (i.e. brake lights turn off just as the car comes to a complete stop), and regardless of the regen paddle on the steering wheel. The only exception I can think of is coasting down a steepish hill in L, which might produce zero g's of deceleration. Anyone think otherwise? Maybe someday when I have a lot of time on my hands, I'll put a stopwatch on the speedometer and check that out.

Thanks again, Lauren.

You're very welcome, phil0909! We're glad we could help provide more information/clarification.

Amber G.
Chevrolet Customer Care

 

[roperld]

0-30-mph time is important for city-town driving. I have read that the CBEV 0-30-mph time is 2.9 seconds. I assume that is for D mode. What is the 0-30-mph time for:
*L mode?
*D/Sport mode?
*L/Sport mode?