Any difference between regeneration in Hill mode versus light braking?

[drliu]

I assume that hill 1 and hill 2 modes are essentially like cruise control for braking-- i.e., they simply force a light degree of regenerative braking whenever the car is not accelerating. If this assumption is correct, then excellent braking technique is always at least as good (and probably better) than Hill mode for energy savings, since there's less risk of over-braking (which requires acceleration and therefore some wasted energy).

Of course if you happen to be traveling down (and up) long hills then it can be more convenient to "ride the brake" automatically using hill mode-- I'm just speaking strictly about the efficiency of energy regeneration being the same for a given G-value of braking manually or in hill mode.

Is this thinking correct?

[Deep Ocean]

I use hill mode a lot but question whether it makes the difference versus using the brakes. It can be dangerous for people behind you as the car slows down very quickly with no brake lights to warn the people behind you.

[LonePalmBJ]

Originally Posted by Deep Ocean

I use hill mode a lot but question whether it makes the difference versus using the brakes. It can be dangerous for people behind you as the car slows down very quickly with no brake lights to warn the people behind you.

The car slows down in Hill 2 no more quickly than downshifting in a manual transmission, which also doesn't illuminate the brake lights. Personally I'm glad the brake lights don't come on the moment I take my foot off the accelerator, even in Hill 2. It would be very annoying to drive behind a car that did that.

Optimally, it might be a good idea to have the brake lights come on automatically based on an accelarametor, perhaps whenever the deceleration exceeds a threshold like .5G. That way the brake lights aren't displaying unnecessarily (for example if you're in hill mode descending a grade) or using Hill mode to gently slow down on flat roads, but do come on when there's a need to alert following drivers.

[kwsmith007]

My experience has been that hill 2 mode is wonderful for driving in heavy traffic. It essentially gives you single lever control of the vehicle speed. I find with a little bit of anticipation you can modulate your speed and vehicle spacing using only the accelerator pedal and as such it's less tiring driving in stop and go traffic.

I also agree with LonepalmBJ that the automatic braking in hill 2 mode is less dramatic than in any real sports car with a high compression engine. I commuted in stop and go traffic for years in a normally aspirated Porsche 911 and it decelerated in second gear much faster than the Fisker does in Hill 2 mode.

[Richard Carnes]

I had a new experience in hill 2 this morning. It was a near miss (or as George Carlin used to say, a near 'hit') when this moron pulled out in front of me making a left hand turn into traffic. At the time I was using hill 2 to slow down, and was only going about 25, but had to put the brake pedal to the floor in an instant, and am happy to report Karma performed with perfection. Strange thing though, was that I came to a complete stop for only a split second, and then continued on my way, and then noticed that hill 2 mode had turned itself off. I was back to "D" without doing anything except the quick braking. Perhaps it's a normal reaction to full braking, but I don't know. Anyone else have something similar?

[8AVGMPG]

Are you sure you didn't grab the paddle shifter inadvertently during the "panic" stop?

[marswill]

Originally Posted by Richard Carnes

I had a new experience in hill 2 this morning. It was a near miss (or as George Carlin used to say, a near 'hit') when this moron pulled out in front of me making a left hand turn into traffic. At the time I was using hill 2 to slow down, and was only going about 25, but had to put the brake pedal to the floor in an instant, and am happy to report Karma performed with perfection. Strange thing though, was that I came to a complete stop for only a split second, and then continued on my way, and then noticed that hill 2 mode had turned itself off. I was back to "D" without doing anything except the quick braking. Perhaps it's a normal reaction to full braking, but I don't know. Anyone else have something similar?

I had the exact same situation happen to me last week with the same result. Hill 2 went to D. I hate it when a person makes a left turn without any regard to oncoming traffic.

[Don A]

Originally Posted by Richard Carnes

I had a new experience in hill 2 this morning. It was a near miss (or as George Carlin used to say, a near 'hit') when this moron pulled out in front of me making a left hand turn into traffic. At the time I was using hill 2 to slow down, and was only going about 25, but had to put the brake pedal to the floor in an instant, and am happy to report Karma performed with perfection. Strange thing though, was that I came to a complete stop for only a split second, and then continued on my way, and then noticed that hill 2 mode had turned itself off. I was back to "D" without doing anything except the quick braking. Perhaps it's a normal reaction to full braking, but I don't know. Anyone else have something similar?

Yes, either Hill mode will be canceled if loss of traction is detected. I expect you activated the ABS during the stop. Hill mode is also turned off during traction loss while accelerating. There is an annoying ripple in the road at an intersection on my daily commute that frequently triggers traction control and resets my Hill mode when I need to accelerate quickly.

[SoCalGuy]

This also happens when shifting from D to R and back to D. One of my wishful features was for Fisker to keep that static when shifting.

[marswill]

Originally Posted by SoCalGuy

This also happens when shifting from D to R and back to D. One of my wishful features was for Fisker to keep that static when shifting.

Or even just "D" to "P" and back.