[Cheapergear]

It's been almost two years since I've had my 2014 Volt, but I keep learning new things about it. Recently, I did a comparison between driving in L vs D and discovered that driving in D was slightly more efficient for me. This was attributed to the fact that gliding was probably more efficient than doing more regen with L. My previous car was a Prius and since pulse and glide usually produces the most efficiency, I was thinking that using sport mode to get up to speed quickly and gliding until the next stop could increase my efficiency. So, after a couple of comparisons, it seems that sport mode was about the same or slightly more efficient than normal mode. One thing that surprised me, however, is the fact that driving in L in sport mode seemed to be about as efficient or more efficient than D. This goes counter to my previous trial where D was more efficient than L. However, with the small sample size and road construction and changing weather, its hard to be absolutely certain. I'm surprised that no one else has made a more quantitative study on this.

 

[jsmay311]

1. No.
2. You can accelerate just as fast in Normal as in Sport anyway.

 

[Norton]

... One thing that surprised me, however, is the fact that driving in L in sport mode seemed to be about as efficient or more efficient than D. ....

Sport Mode only changes how the car responds to you right foot input. It does not add or subtract power.
Same thing with D v L.

It's all a matter of how you use your right foot.

If the accel and decel rates are the same, how could there be any 'efficiency' differences?

Get a G-Meter like app on your phone and try again with the same driving styles in any mode you like.

 

[Cheapergear]

Sport Mode only changes how the car responds to you right foot input. It does not add or subtract power.
Same thing with D v L.

It's all a matter of how you use your right foot.

If the accel and decel rates are the same, how could there be any 'efficiency' differences?

Get a G-Meter like app on your phone and try again with the same driving styles in any mode you like.

Folks. I realize all of that. I'm not saying the mode itself is doing anything. I'm saying it may help produce those result when I'm driving normally to achieve a better pulse and glide. Do some folks not believe that pulse and glide is more economical than normal driving?

 

[wordptom]

Regen recaptures power used to accelerate the Volt from a standing start or from one speed to a higher speed. Any power used to maintain speed is irrecoverable - the amount of regen depends on your speed, not on how long you’ve been driving at that speed. Coasting in D gets you a little regen for a longer time. The extra regen you might get by maintaining speed until you’re closer to the stop sign, red light, or traffic slowdown, and then using L or the paddle, is offset by the extra power you used to maintain speed to get there.

If the amount of level terrain regen is proportional to the speed, would arriving at that speed sooner by using sport mode translate into more time using irrecoverable power to maintain speed until the next need to slow down? Or, of course, if you start coasting the moment you reach the cruising speed (pulse and glide?), then you start to regen sooner in sport mode...

 

[llninja]

I've stopped hypermiling (grandpa mode) about 2 years ago. I now drive it like a jackrabbit in Normal D and don't worry at all about EV range. Instead of squeezing 90 MPG, I'm now getting 70 MPG, but taking on any and all pony cars and ricer boys in the process. Try it. You might never go back.

What you are probably seeing is shorter pulsing thus longer gliding. Try a few days of flooring it in NormalD and gliding to see if that achieves the same effect that Sport and glide is doing over NormalD and glide. Are you gliding in D or popping it into N to coast like the dickens?

The king of EV range on this forum is Ari_C. He drives very gently, glides a lot in N, and achieved 81.1 miles on a 2011 Gen1 driving in a big rectangle for 4 hours at 20-25 MPH one Memorial Day weekend when he was bored.

 

[obermd]

The king of EV range on this forum is Ari_C. He drives very gently, glides a lot in N, and achieved 81.1 miles on a 2011 Gen1 driving in a big rectangle for 4 hours at 20-25 MPH one Memorial Day weekend when he was bored.

Shouldn't that be "when he wanted to be bored"?

 

[obermd]

Regen recaptures power used to accelerate the Volt from a standing start or from one speed to a higher speed. Any power used to maintain speed is irrecoverable - the amount of regen depends on your speed, not on how long you’ve been driving at that speed. Coasting in D gets you a little regen for a longer time. The extra regen you might get by maintaining speed until you’re closer to the stop sign, red light, or traffic slowdown, and then using L or the paddle, is offset by the extra power you used to maintain speed to get there.

If the amount of level terrain regen is proportional to the speed, would arriving at that speed sooner by using sport mode translate into more time using irrecoverable power to maintain speed until the next need to slow down? Or, of course, if you start coasting the moment you reach the cruising speed (pulse and glide?), then you start to regen sooner in sport mode...

There's a line between accelerating quickly to not waste energy at low speeds vs. accelerating so quickly that you waste energy fighting inertia.

 

[quirkySquirt]

There's a line between accelerating quickly to not waste energy at low speeds vs. accelerating so quickly that you waste energy fighting inertia.

I thought that's what the efficiency indicator was for (the green circle or the green bar graph with the leaf icon floating on it). I always try to accelerate and brake based on that indicator when I'm hypermiling. It's how I get a 65 mile commute out of a 53 mile EPA range on fairly hilly terrain.

 

[AZ EV Driver]

Folks. I realize all of that. I'm not saying the mode itself is doing anything. I'm saying it may help produce those result when I'm driving normally to achieve a better pulse and glide. Do some folks not believe that pulse and glide is more economical than normal driving?

Well I'll go there. In the world of ICE vehicles pulse and glide probably works OK, but to do it properly it would be moderate accel in gear then glide in neutral (maybe even with the engine off). With an EV you want to limit the current draw to a minimum on the accel side then glide in neutral. Some will argue that you are giving something away without the recapture of energy with regen, but regen efficiency isn't all that great.

You can drive like that if you want, but you will drive everyone around you crazy. Hardly worth it in my mind. I would recommend using the green ball as a guide and try to maintain a constant speed as much as possible by timing the traffic lights to avoid slowing down in city traffic. On the highway stay at or below 62 mph.

VIN # B0985

 

[Norton]

.... Do some folks not believe that pulse and glide is more economical than normal driving?

I for one do not believe that 'Pulse and Glide' applies to EV's.
That is an old Gasser technique. An engine is more efficient with the throttle wide open (pumping losses), then engine off and glide.

It takes X amount of power to roll the car down the road at any given speed.
With an EV there is one way to use the least amount of power to do that job.

With an EV there is an advantage (sometimes) to shifting to N, thus getting a true coast and minimizing regen.
Is that the 'Pulse and Glide' you are talking about?

 

[canehdian]

I thought that's what the efficiency indicator was for (the green circle or the green bar graph with the leaf icon floating on it). I always try to accelerate and brake based on that indicator when I'm hypermiling. It's how I get a 65 mile commute out of a 53 mile EPA range on fairly hilly terrain.

Hate to break it to you, but unless they actually did work on it for gen 2, it's just a fun little picture that's mostly lying to you
(For gen 1) It doesn't actually position the ball based on the real time efficiency of the drivetrain at all. It arbitrarily moves it based on very limited information.
For example, driving over 100km/h the ball will always be slightly elevated. Always. Even if you're coasting at 0KW, which is as efficient as you can get. It's arbitrarily linked to the speed.
And as for the going way up on hard acceleration? It's not tied to KW at all - it's tied to the accelerator pedal position.
How do I know this? I've done a hard accel out of the work parking lot and hit a small pothole which momentarily caused wheel slip and triggered stability control. The absolute power was then cut for a few seconds (as the computer does during ESC events) - so pedal was down full but KW was only 50-60 or so and the "efficiency indicator" was at the very top of the screen. Normally at 50-60 kW it would be just entering the yellow range.

In the grand scheme of things, it will help you be more gentle and efficient by giving some reasonable feedback. But it's not actually an indicator of real efficiency, unfortunately.

 

[srmarti]

Sport mode just remaps the throttle response. The potential efficiency I think is the same. Maybe if it suits the driver's style it might be better. Seems more likely to be harder to keep from accelerating too hard for most drivers.

 

[quirkySquirt]

Hate to break it to you, but unless they actually did work on it for gen 2, it's just a fun little picture that's mostly lying to you
(For gen 1) It doesn't actually position the ball based on the real time efficiency of the drivetrain at all. It arbitrarily moves it based on very limited information.
For example, driving over 100km/h the ball will always be slightly elevated. Always. Even if you're coasting at 0KW, which is as efficient as you can get. It's arbitrarily linked to the speed.
And as for the going way up on hard acceleration? It's not tied to KW at all - it's tied to the accelerator pedal position.
How do I know this? I've done a hard accel out of the work parking lot and hit a small pothole which momentarily caused wheel slip and triggered stability control. The absolute power was then cut for a few seconds (as the computer does during ESC events) - so pedal was down full but KW was only 50-60 or so and the "efficiency indicator" was at the very top of the screen. Normally at 50-60 kW it would be just entering the yellow range.

In the grand scheme of things, it will help you be more gentle and efficient by giving some reasonable feedback. But it's not actually an indicator of real efficiency, unfortunately.

I have noticed that the leaf indicator (I don't use the green circle) rises and falls fairly well with how many Gs I'm feeling. So the harder I accelerate or decelerate, the leaf indicator shows accordingly. If it is a simple indicator not tied to real sensors for measuring vehicle efficiency, it's faking the job pretty well. It's taught me to be a little more calm in my acceleration and deceleration behavior. Dunno if that's actually the cause of my 65 miles range now. Probably very little as rerouting my commute to avoid highways and hills has done more I think to reduce energy consumption.

 

[canehdian]

I have noticed that the leaf indicator (I don't use the green circle) rises and falls fairly well with how many Gs I'm feeling. So the harder I accelerate or decelerate, the leaf indicator shows accordingly. If it is a simple indicator not tied to real sensors for measuring vehicle efficiency, it's faking the job pretty well. It's taught me to be a little more calm in my acceleration and deceleration behavior. Dunno if that's actually the cause of my 65 miles range now. Probably very little as rerouting my commute to avoid highways and hills has done more I think to reduce energy consumption.

Like I said, they may have revised it for gen2.
Or it could be as simple as the fact that your pedal position is correlated with the number of G's you feel, because how else is the vehicle suddenly slowing or stopping?

Try going extra fast on the freeway, the efficiency indicator should be above centre. Then reduce your pedal pressure to a perfect coast (0-0.5kW power). Is the ball perfectly centred? I'm going to guess it's above centre still. Obviously not as high as when actively accelerating, but still not in the middle. This, despite 0kW being as efficient as you can get when driving at that speed.

 

[scrambler]

2. You can accelerate just as fast in Normal as in Sport anyway.

This is not quite true.
In normal mode, you have access to a slow power ramp between zero and max, and Max acceleration at max
In Sport mode, you have access to a fast power ramp between zero and Max, and MAx acceleration at Max.

So it is true that when using Max acceleration, you get the same in Normal mode and in Sport mode, but for every acceleration level below Max, Sport mode will give your a faster acceleration

 

[llninja]

This is not quite true.
In normal mode, you have access to a slow power ramp between zero and max, and Max acceleration at max
In Sport mode, you have access to a fast power ramp between zero and Max, and MAx acceleration at Max.

So it is true that when using Max acceleration, you get the same in Normal mode and in Sport mode, but for every acceleration level below Max, Sport mode will give your a faster acceleration

When you mash the accelerator to the floor in either Normal or Sport, you will get identical results. The only difference is if you push the accelerator 1/3 or 1/2 way, sport will make you feel like the car is faster, but it's fake, just like the new iPhone home button isn't really a button - the buttonpress click is simulated.

 

[quirkySquirt]

Like I said, they may have revised it for gen2.
Or it could be as simple as the fact that your pedal position is correlated with the number of G's you feel, because how else is the vehicle suddenly slowing or stopping?

Try going extra fast on the freeway, the efficiency indicator should be above centre. Then reduce your pedal pressure to a perfect coast (0-0.5kW power). Is the ball perfectly centred? I'm going to guess it's above centre still. Obviously not as high as when actively accelerating, but still not in the middle. This, despite 0kW being as efficient as you can get when driving at that speed.

I'll have to try this tomorrow. A similar test was when I have 45mph set on my cruise when going along a road that has changing grades. So on the flat part, it shows 4kW instantaneous usage but once I hit the steeper part, it climbs to 20kW as I slow down to 44mph but once it speeds up to 45mph (takes a few seconds to do this on the steep hill), it drops to 10kW and holds there until I reach the top of the hill at which point I comes back to 4kW again.

I never paid attention to the efficiency indicator when I do this but will for tomorrow's commute.

 

[JRRF]

When you mash the accelerator to the floor in either Normal or Sport, you will get identical results. The only difference is if you push the accelerator 1/3 or 1/2 way, sport will make you feel like the car is faster, but it's fake, just like the new iPhone home button isn't really a button - the buttonpress click is simulated.

Max power is max power. But the sensation is real. For anyone who doesn't go around mashing the accelerator to the floor at every stoplight, the effect of Sport mode is very real.

 

[Norton]

All this talk of 'Modes' and 'Efficiency',,,
It all comes down to how YOU use your right foot.
The car ONLY responds to that, no matter what buttons you press or lever positions.