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Discussion Starter #1
This might be addressed elsewhere, but I can't find it.

When you shift from "D" to "L" (or vice versa) what exactly is the change? I assume it's a mechanical change of some kind (as opposed to an electrical change) since there is a noticable change in drag when shifting to "L" while coasting.
 

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It's a software change only. It remaps the accelerator pedal so you can control both acceleration and deceleration (regenerative braking only) with one foot. Many people really like it in traffic. You can get exactly the same performance using both the brake and gas pedals. For example if you are in L and don't let off the gas pedal all the way you can "coast". Or if you are in D and you lightly brake you can get the same regen as in L with no brakes applied. Your preference.

One other thing, when in L and decelerating with your foot off the gas pedal, the brake lights are not on. That's because the deceleration rate in somewhere between the "you may not" and "you may" limits set by the FMVSS regulations. It's similar to the rate you get by downshifting a manual transmission.
 

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Discussion Starter #4
Thanks, guys! That info does correct some of the assumptions I'd made.

I'm blogging about owning an EV on my company's intranet (trying to drum up some interest...I work at the electric company for Heaven's sake). Really want to make sure anything I post is accurate.
 

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The other advantage to using the higher regen rates of "L" mode is that you don't touch the brake pedal for Most slowing down, and therefore don't push the brake pads out towards the brake rotors at all. This reduces brake pad wear - a Lot.

You don't realize how often you normally "feather" the brakes in a normal car until you drive the Volt in "L", and Don't keep reaching for the brake pedal..

As has been stated before - NO, the brake lights don't come on when slowing with just regen. I have Not found that to be a problem, even in traffic. I've gotten to the point where I drive the thing in "L" Always, no matter what or where.

I've gotten used to driving it with one foot (mostly), and find that driving anything Else that Doesn't slow when lifting the "gas" pedal foot just feels wrong. Antiquated..
 

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I drove a Plug in Prius the other day at a competitive vehicles Ride and Drive here at GM. Do you really have to push the lever on the dash down every time you want it to engage Toyota's equivalent of L?
 

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One other thing I notice in L is when at very low speeds there is a very slight clunk when going from coasting to lightly pressing on the accelerator. When I shift into D, I do not notice the clunk. I am assuming this is the regen brake being engaged.
 

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I love L - will never go back. It is so easy to drive - especially in traffic!! Driving a normal car now seems so wasteful with braking. The funny thing - when I get in our Honda Van - I keep putting the transmission into 1st or 2nd vs. D - I'm used to the number of clicks you get when pushing our Volt lever into L.
 

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Geez, I skipped right over that part of the manual assuming L was for low! Wow, I feel stupid now! Going to try L on my way home!
 

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Don't like L

I actually don't prefer to drive in L mode as I like coasting the car and it feels really unnatural after using a regular ICE car for years. If you're good at feathering the brakes (takes a bit of skill and practice to do right) then you can brake manually and achieve pretty much the same power savings. L does come useful in massive downhills where you might be going down the side of a mountain and otherwise holding down on the brake all the time.
 

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Its just perception, there is absolutely nothing the car does different if you use two pedals vs one

D mode - two pedal = #1 variable regen for brakes unless panic stop #2 the go pedal
L mode - one pedal = #1 push for go, feather for the regen amount for slowing down.
 

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I've gotten used to driving it with one foot (mostly), and find that driving anything Else that Doesn't slow when lifting the "gas" pedal foot just feels wrong. Antiquated..

Well, IF you leave a proper space cushion and anticipate when the traffic will be slowing down, you should be able to do that in pretty much ANY vehicle......to some extent anyway.
 

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Geez, I skipped right over that part of the manual assuming L was for low! Wow, I feel stupid now! Going to try L on my way home!
As a potential future owner, I'd be interested to hear what the manual actually says about L.

I know that most owners believe that it only effects the regen braking but I find that a little hard to believe.

Seems like it should give you more torque by changing the transmission characteristics some too.
 

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It's a software change only. It remaps the accelerator pedal so you can control both acceleration and deceleration (regenerative braking only) with one foot. Many people really like it in traffic. You can get exactly the same performance using both the brake and gas pedals. For example if you are in L and don't let off the gas pedal all the way you can "coast". Or if you are in D and you lightly brake you can get the same regen as in L with no brakes applied. Your preference.

One other thing, when in L and decelerating with your foot off the gas pedal, the brake lights are not on. That's because the deceleration rate in somewhere between the "you may not" and "you may" limits set by the FMVSS regulations. It's similar to the rate you get by downshifting a manual transmission.
Hi Pete,

I have a question; I drive in D as I don't like the sudden deceleration when driving in L. However, I have always switched to L when coming to a red light or whenever safe to recapture as much energy before braking.

Then the last couple of days I started thinking that all this shifting back and forth from L to D may not be the best thing for my Volt.

Sometimes the light changes and I switch back quickly from L to D and get a little "jerk."

So my question is, does this behavior I described offer more regen than just coasting as far as possible then using the brakes to finish up the stop, and is what I'm doing potentially harmful?
 

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As a potential future owner, I'd be interested to hear what the manual actually says about L.

I know that most owners believe that it only effects the regen braking but I find that a little hard to believe.

Seems like it should give you more torque by changing the transmission characteristics some too.
You are WRONG. Only affects regen mode. Here is what the manual says in section 9-29

"L(Low): This position reduces vehicle speed without using the brakes. You can use L (Low) on hills. It can help control vehicle speed going down steep mountain roads along with using the brakes off and on. You can use L (Low) on very steep hills, in deep snow,
or in mud."
 

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Hi Pete,

I have a question; I drive in D as I don't like the sudden deceleration when driving in L. However, I have always switched to L when coming to a red light or whenever safe to recapture as much energy before braking.
Just leave it in D! Using the brake pedal in D is still regeneration, recapturing energy, unless you are braking hard enough that kicking in the pads is necessary, or the last few mph before complete stop where regen is ineffective. You can see the regen in the power flow display in a 2013+ model. Using L does not "save the pads" as another poster suggested; it is the regenerative braking that saves the pads, and this is utilized in both modes, the mode just remaps the range in which it kicks in between the two pedals. The Volt is *not* designed like Tesla, in a Tesla the regen is exclusive to releasing the accelerator, and the brake pedal is friction braking. The Volt is designed like the Prius to use regen with the brake pedal, pads are known to last nearly forever on a Prius & the same should be true of Volt.

Just anticipate the stops, slow down early, brake early with moderate pressure, to avoid hard braking unless you have to.
 

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Just leave it in D! Using the brake pedal in D is still regeneration, recapturing energy, unless you are braking hard enough that kicking in the pads is necessary, or the last few mph before complete stop where regen is ineffective. You can see the regen in the power flow display in a 2013+ model. Using L does not "save the pads" as another poster suggested; it is the regenerative braking that saves the pads, and this is utilized in both modes, the mode just remaps the range in which it kicks in between the two pedals. The Volt is *not* designed like Tesla, in a Tesla the regen is exclusive to releasing the accelerator, and the brake pedal is friction braking. The Volt is designed like the Prius to use regen with the brake pedal, pads are known to last nearly forever on a Prius & the same should be true of Volt.

Just anticipate the stops, slow down early, brake early with moderate pressure, to avoid hard braking unless you have to.
I agree. When I get to my destination, the brake rotors are all still cold when I drive in "D".

In my opinion, driving in "L" pretty much just turns your brake lights off for the driver behind you and increases the chance of a tailgater nailing you from behind. I can understand where driving in "L" can have its purpose in certain conditions, but I can't see where doing it all the time regenerates any more than being easy on the brake pedal.
 
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