Too much regen in D mode

[Anonymous]

I just switched from Volt to Bolt - yesterday. I love the car so far and am excited about the range.

One disappointing thing is that you can't coast easily in D mode like you can in the Volt. I'd rather use my momentum to keep going rather than having the car slow when I let off the accelerator then have to speed back up again. It is obviously more efficient to avoid the change from kinetic to battery energy then back again. Plus it is more enjoyable to me to have the smooth coast.

By using the brake very judiciously, I can usually get all the regen I want by slowing well before the red light or stop sign. If I time it right, I don't need to use either the brake or the accelerator which is most efficient.

Is there any way to turn off the regen in D mode? That would seem to be a simple thing to give as an option.

Thanks,

 

[GernBlanston]

You just have to feather it.
Just let off enough to 'coast'.
You'll get used to it.

 

[PV1]

How long do you usually coast? It's easy to slip into Neutral and truly coast when you want. Hold the shifter forward for a second. To go back to Drive, just click it back.

Just be aware that you have to go back into Drive to get power or regen.

 

[redpoint5]

I'm annoyed that almost all manufacturers feel the need to carry over this useless behavior. As the lead engineer for the Bolt said, they wanted the car to slow at a rate that is similar to what drivers had experienced in other (automatic) vehicles.

As many of us know, the slowing of an automatic car is not a designed feature, but rather a consequence of how torque converters work. Manual (used to be called standard) transmission cars have a true coast whenever the clutch is pushed. Another annoying "feature" is that the car creeps forward when releasing the brake in D mode. Again, vehicle creep isn't something that was designed in, but rather a consequence of how a torque converter works in an automatic transmission. Manually shifted vehicles don't creep.

My Prius also has no way to bypass regen when letting off the accelerator. Feathering the pedal is tricky because it's impossible to get it exactly right. You will always either be supplying some power, or regenerating some amount. I've grown accustomed to shifting to neutral to coast, and then putting it back in D just before slowing down with regen.

The real shame is that it would cost nothing to make these 2 antiquated behaviors optional to the driver, except for the increased incidence old people bringing their car to the dealership not realizing the setting they had inadvertently set.

 

[sgt1372]

LOL!

I think that D modes doesn't have enough regen effect and don't like the way it continues to roll after I release the accelerator. So, I just drive it L mode all the time. Accelerates and decels much more predictably and efficiently for me in this way

Funny how we all want/like different things.

 

[Pigwich]

I'm annoyed that almost all manufacturers feel the need to carry over this useless behavior. As the lead engineer for the Bolt said, they wanted the car to slow at a rate that is similar to what drivers had experienced in other (automatic) vehicles.

I'm on the fence here - I completely see your point, and you make a great argument, and nothing you say is false in any way, BUT literally everybody in the world is used to a certain behavior, and to have to re-train everybody is daunting. When somebody hops in a car, if it acts "funny" they don't want to drive it. I can appreciate it being an option, but again, you're 100% right on the service calls that would be generated.

There's also an argument to be made for safety, and I think this may be the biggest one, going back to what people are "used to" and that is they're used to a certain amount of slowing down when they let their foot off the throttle. If the car keeps coasting, it might be a surprise. I drove a gas car for 20 years before my first EV - That's a lot of muscle memory to get rid of.

On the other hand, and completely counter to your opinion is that there isn't ENOUGH regen when you lift off the pedal. I drive in god-awful traffic every day, thankfully only for a few miles, but the argument can be made, and I will make it, that the extra 300 milliseconds of deceleration you get when driving in L when you go from throttle to brake might make the difference between a fender bender and a close call.

Ultimately, however, it's up to the driver as to what kind of behavior they want. More and more people are enjoying one-pedal driving in EVs, which is MORE regeneration, but it does take some time getting used to it. I take a lot of people for test drives in my car, and L drives them crazy at first. But driving driving in L has it's own safety concerns. A good one can be made regarding people NOT holding their foot on the brake when they come to a complete stop with one pedal driving. This is a problem, since a car struck from the rear can more easily be pushed into the path of traffic with deadly consequences.

Your call, as a driver, it it could be a choice but as far as I can see, you're facing an uphill battle for popularity of this feature.

Maybe some hacker type person can find out which PID it is that needs to get changed and they can help you out?

 

[NeilBlanchard]

I agree with redpoint5 - we need an option for free wheel coasting in D. It should be the default, but it should be the driver's choice, at least.

The e-Golf and the Ioniq EV have coasting, and it is the most efficient. But, for the moment, like the Leaf, I will be shifting it into neutral.

 

[redpoint5]

I'm annoyed that almost all manufacturers feel the need to carry over this useless behavior. As the lead engineer for the Bolt said, they wanted the car to slow at a rate that is similar to what drivers had experienced in other (automatic) vehicles.

I'm on the fence here - I completely see your point, and you make a great argument, and nothing you say is false in any way, BUT literally everybody in the world is used to a certain behavior, and to have to re-train everybody is daunting. When somebody hops in a car, if it acts "funny" they don't want to drive it. I can appreciate it being an option, but again, you're 100% right on the service calls that would be generated.

There's also an argument to be made for safety, and I think this may be the biggest one, going back to what people are "used to" and that is they're used to a certain amount of slowing down when they let their foot off the throttle. If the car keeps coasting, it might be a surprise. I drove a gas car for 20 years before my first EV - That's a lot of muscle memory to get rid of.

But drivers had to learn to get used to the slight deceleration and creep introduced with automatic transmissions. I can't see the lack of slight deceleration causing a safety concern, and I certainly see a huge safety issue with allowing a vehicle to creep without any driver input. I've been driving for almost 20 years myself, and I'm used to coasting with the clutch in, and no creep from a manual transmission. I'm in the minority in the US, but manual transmissions are still popular in many places around the world.

On the other hand, and completely counter to your opinion is that there isn't ENOUGH regen when you lift off the pedal. I drive in god-awful traffic every day, thankfully only for a few miles, but the argument can be made, and I will make it, that the extra 300 milliseconds of deceleration you get when driving in L when you go from throttle to brake might make the difference between a fender bender and a close call.

I was considering whether the instant braking from letting off the accelerator would prevent more accidents, or train people to be unfamiliar with the brake pedal when they really need to emergency brake. I'll be curious to see how this one plays out as 1-pedal driving becomes more common.

As the OP mentioned, it's way more efficient to drive in D mode and coast down than it is to regen. Almost everyone drives bumper to bumper though, and in that case it's more efficient to regen than use friction brakes.

I actually get better fuel economy in gridlocked Portland traffic in my manual transmission car than highway driving. The reason is that I drive the average speed of traffic, allowing a gap to form when people are racing ahead to the next slowdown, and shrinking the gap as I approach the next slowdown. This avoids the brakes as much as possible. I even counted the cars that moved into the gap I created and subtracted when they left my lane. In 1 hour of driving, a total of 11 extra cars got ahead of me. 11 cars in an hour of more relaxed driving adds mere seconds to my commute time while smoothing traffic out for everyone behind me and getting excellent fuel economy.

So you see, for my unusually safe driving technique, a true coast mode makes driving more efficient and less stressful.

The VW Golf EV has something like 4 levels of regen, from pure coasting to 1-pedal driving. Might as well make it an option if it costs nothing to implement.

 

[dandrewk]

How long do you usually coast? It's easy to slip into Neutral and truly coast when you want. Hold the shifter forward for a second. To go back to Drive, just click it back.

Just be aware that you have to go back into Drive to get power or regen.

Very bad and potentially dangerous suggestion. The manual clearly advises against using "N" in normal driving conditions.

Besides potentially overheating your brakes, you may run into a situation where you need power -instantly- in order to avoid an accident.

 

[HotPotato]

How long do you usually coast? It's easy to slip into Neutral and truly coast when you want. Hold the shifter forward for a second. To go back to Drive, just click it back.

Just be aware that you have to go back into Drive to get power or regen.

Very bad and potentially dangerous suggestion. The manual clearly advises against using "N" in normal driving conditions.

Besides potentially overheating your brakes, you may run into a situation where you need power -instantly- in order to avoid an accident.

Operationally, that's no different than coasting in neutral with a manual transmission and popping back into gear if you need acceleration or engine braking. Easier, even: no clutch!

 

[sgt1372]

Operationally, that's no different than coasting in neutral with a manual transmission and popping back into gear if you need acceleration or engine braking. Easier, even: no clutch!

This is actually illegal to do in CA.

It originated in the days of non-synchchomesh transmissions when commercial truck drivers would do that b4 stopping and then couldn't get back into gear until they completely stopped.

Sometimes their brakes failed b4 they could do that. So they adopted a vehical code violation against it

Not so much an issue now w/synchromesh but the vehicle code violation for doing it is still on the books.

Think it just applies to manual trannys but you could have problems getting back into gear w/an auto.

Generally NOT an advisable thing to do while moving, violation or not.

 

[GetOffYourGas]

I agree with the OP. Or at least inasmuch as one should be able to turn it off. I love the eGolf's programability - the driver selects as much or as little regen as desired.

 

[dandrewk]

The Bolt is a small car, but it is very heavy due to those batteries. It takes a lot of stopping power to slow/stop this vehicle, so having some level of regen or transmission slowing is a very good thing.

I'd hate for some Bolt driver, in a quest to increase his/her efficiency, coast downhill from the I5 Grapevine into the LA suburbs in "N", only to find that using 100% friction brakes has caused them to overheat. Ever try and use overheated brakes to slow/stop a car? Get ready to scream "WTF??!!"...

 

[devbolt]

I agree with the OP. Or at least inasmuch as one should be able to turn it off. I love the eGolf's programability - the driver selects as much or as little regen as desired.

And in the Bolt, the driver has that capability, too. It's called L mode and feathering the accelerator pedal. My wife figured it out pretty quickly when I showed it it to her. You can do the same in D mode, just less regen, and maybe a bit more pedal travel needed.

 

[redpoint5]

The Bolt is a small car, but it is very heavy due to those batteries. It takes a lot of stopping power to slow/stop this vehicle, so having some level of regen or transmission slowing is a very good thing.

I'd hate for some Bolt driver, in a quest to increase his/her efficiency, coast downhill from the I5 Grapevine into the LA suburbs in "N", only to find that using 100% friction brakes has caused them to overheat. Ever try and use overheated brakes to slow/stop a car? Get ready to scream "WTF??!!"...

We're not talking about riding the brakes down the grapevine in N, we're talking about having a true coast mode. If the car had a true coast mode, there would never be a reason to manually shift into N.

The brakes are engineered appropriately to stop the vehicle regardless of regen.

Imagining a false scenario to justify your opinion that people shouldn't have the option to coast is absurd. I prefer my brake pedal to decelerate the vehicle, the accelerator pedal to provide propulsive power, and the absence of any input to observe Newton's first law of motion.

 

[GetOffYourGas]

I agree with the OP. Or at least inasmuch as one should be able to turn it off. I love the eGolf's programability - the driver selects as much or as little regen as desired.

And in the Bolt, the driver has that capability, too. It's called L mode and feathering the accelerator pedal. My wife figured it out pretty quickly when I showed it it to her. You can do the same in D mode, just less regen, and maybe a bit more pedal travel needed.

Yes and no. Feathering the accelerator is NOT the same thing as having a true "coasting" mode. It's the same result in terms of the car driving, but requires far different input from the driver.

I don't understand why people are so afraid of have this as an option. Not even the default option. Just an option.

 

[GetOffYourGas]

We're not talking about riding the brakes down the grapevine in N, we're talking about having a true coast mode.

This. In this mode, there is no reason not to blend regen with friction brakes when the driver presses the brake pedal.

 

[PV1]

The Bolt is a small car, but it is very heavy due to those batteries. It takes a lot of stopping power to slow/stop this vehicle, so having some level of regen or transmission slowing is a very good thing.

I'd hate for some Bolt driver, in a quest to increase his/her efficiency, coast downhill from the I5 Grapevine into the LA suburbs in "N", only to find that using 100% friction brakes has caused them to overheat. Ever try and use overheated brakes to slow/stop a car? Get ready to scream "WTF??!!"...

Umm, why would anyone use friction brakes while purposely shifting into Neutral in the Bolt? Drop it back into Drive/Low if you need to slow down. Using Neutral is only to shut off regen for coasting, not bypass the motor and rely on friction brakes (which would be way more wasteful than the 13 kW of regen induced in Drive mode).

Folks have done hundreds of thousands of miles in EVs and coast in Neutral. I don't think anyone's overheated brakes.

 

[sparkyps]

I have zero interest in the added complexity of a "coast mode"

I rarely use the brake pedal and can accelerate, coast and slow down exactly like I want to using just the rightmost pedal and have instant responsiveness (faster/slower) without any complexities like switching in/out of a coast mode.

I have a stick shift car too and I simply don't drive the Bolt like I drive the stick shift. I also have a car with an automatic transmission and I would never put it in neutral while driving. That manual transmission cars are routinely taken out of gear is no reason to think that's how we should drive an EV.

I don't coast down hills either, I pick a speed and regen maintains that speed for me. Utterly unlike driving with a manual or automatic and using a combination of engine braking and brakes to keep my speed from becoming excessive. Driving down hill in an EV is a pleasure, I get to the bottom and likely haven't used my physical brakes once.

 

[redpoint5]

I have zero interest in the added complexity of a "coast mode"

I rarely use the brake pedal and can accelerate, coast and slow down exactly like I want to using just the rightmost pedal and have instant responsiveness (faster/slower) without any complexities like switching in/out of a coast mode.

I have a stick shift car too and I simply don't drive the Bolt like I drive the stick shift. I also have a car with an automatic transmission and I would never put it in neutral while driving. That manual transmission cars are routinely taken out of gear is no reason to think that's how we should drive an EV.

I don't coast down hills either, I pick a speed and regen maintains that speed for me. Utterly unlike driving with a manual or automatic and using a combination of engine braking and brakes to keep my speed from becoming excessive.

There is no added complexity of coast mode. It's simply programming each pedal to do 1 function only; stop or go.

Again, we're not talking about constantly shifting between modes, using N, or riding the friction brakes. If the car had an optional coast mode, I would stay in that mode forever, never having to use N, and using the friction brakes as rarely as everyone else.

The car would still regen going downhill while the cruise control is on. Coast mode would behave just like the other modes, except more efficient for those few people interested in maximizing range or efficiency.

Sure, most people aren't interested in efficiency or paying attention to how they drive. That's why the mode would be optional.

Really, these arguments that "I personally don't care about efficient driving techniques" is not a very compelling reason to be against the option. It's the same as me saying "I never use rinse mode on my dishwasher, therefore nobody should have the option".

...and you might not coast in neutral in your automatic, but I do.