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I originally posted that I use L only. Down long hills though I have found that switching to D makes it easier to maintain the right speed while coasting and regen-ing. I have also discovered that while in L the paddle regens even harder than pulling off the accelerator completely. This means that I use my brakes even less! Awesome!
 

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When the roads are dry or wet I drive in L. If there is any chance or snow or ice on the roads I drive in D. I had my car for a few weeks last year when I drove across a bridge that had iced up, the car started to slide so I took my foot off the throttle while it was in low and the slide got a lot worse due to the regenerative braking. Luckily I realized what was going on and applied enough throttle to get the wheels rolling and kept it on the road and in the lane.
 

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I originally posted that I use L only. Down long hills though I have found that switching to D makes it easier to maintain the right speed while coasting and regen-ing.
Your results differ. I find when using cruise control on long downhills, L will maintain speed precisely and maximize regen.

Sometimes, for reasons known only to them, a passenger will get nervous when the Bolt on cruise isn't slowing down for an approaching curve. You and I know all of today's highways are designed so a current car can safely negotiate the curves at the posted limit. Logic does not pertain for some persons perceptions. CURVE COMING!!! SLOW DOWN!! That there's no necessity doesn't matter. Same with observing brake lights. WTF?? Why was that driver braking?

jack vines
 

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It is more efficient to NOT regen downhill if it is possible because during regen you have small motor and inverter losses, decreasing the amount of energy you get back into the battery. If you just let the vehicle coast you minimize those losses and only have work against air drag and rolling resistance forces (which of course you have with regen too). The difference is small though so I never do it, just leave it in cruise control in L and let it maintain constant speed regardless of terrain. Many places you get going too fast for the curves if you just coast anyway. On the other hand, gas vehicles don't hold constant speed. Even with cruise control they gain speed going downhill so they end up going faster than you making you a hazard in their view - but that is overlooking the highway patrol car at the bottom of the hill...

I don't understand the comment that D makes it easier to maintain speed than L. I guess you don't use cruise control.
 

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It is more efficient to NOT regen downhill if it is possible because during regen you have small motor and inverter losses, decreasing the amount of energy you get back into the battery. If you just let the vehicle coast you minimize those losses and only have work against air drag and rolling resistance forces (which of course you have with regen too). The difference is small though so I never do it, just leave it in cruise control in L and let it maintain constant speed regardless of terrain. Many places you get going too fast for the curves if you just coast anyway. On the other hand, gas vehicles don't hold constant speed. Even with cruise control they gain speed going downhill so they end up going faster than you making you a hazard in their view - but that is overlooking the highway patrol car at the bottom of the hill...

I don't understand the comment that D makes it easier to maintain speed than L. I guess you don't use cruise control.
We agree on most of the above. Especially agree the difference between trying to coast, (not really possible in a Bolt) or using cruise is small. I'd like to see someone prove it actually exists.

jack vines
 

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Which is more efficient, regen vs coasting... it depends. But at the end of the day, it's more important to travel at a safe speed. That would either be setting the car on L or leaving the car on D and depressing the brakes slightly.

Regen we know the total system loss is about 40%.

Coasting at higher speed, you get more air resistance.
 

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Try going down a big hill, and put it in Neutral. You will take off like mad. That is coasting.
There is no 'Neutral' on a Bolt; the wheels and the motor are directly connected through a double reduction gearset. 'Neutral' simply disconnects the motor windings, rendering the right pedal useless. Didn't we determine a while back the transmission oil pump doesn't function in Neutral? Doesn't the 12V fluid pump for the transmission only run when in D, L or R? Without proper lubrication the transmission might be harmed if allowed to run down mountains in Neutral?

Looking at a cross-section of the motor and drivetrain, the right output shaft (which travels through the rotor and drives the right wheel) is supported by a plain bearing. This bearing requires pressure-fed lubrication when the front wheels are turning, and will eventually fry if it doesn't get that pressure-fed lubrication. So coast down mountains early and often and get back to us with how much it saves.

jack vines
 

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It's also against the law in several states to drive in neutral.

If you want actual net zero energy usage, you need to carefully modulate the accelerator pedal to keep the energy usage at zero. This can be done in D or L, but drivers who are used to driving in D, especially those with a fairly binary “on the pedal / off the pedal” style for maintaining speed may be less skilled at doing so than those who regularly drive in L.

Either way, it's a pretty pointless thing to do given that any gains are modest at best.
 

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There is no 'Neutral' on a Bolt; the wheels and the motor are directly connected through a double reduction gearset. 'Neutral' simply disconnects the motor windings, rendering the right pedal useless. Didn't we determine a while back the transmission oil pump doesn't function in Neutral? Doesn't the 12V fluid pump for the transmission only run when in D, L or R? Without proper lubrication the transmission might be harmed if allowed to run down mountains in Neutral?

Looking at a cross-section of the motor and drivetrain, the right output shaft (which travels through the rotor and drives the right wheel) is supported by a plain bearing. This bearing requires pressure-fed lubrication when the front wheels are turning, and will eventually fry if it doesn't get that pressure-fed lubrication. So coast down mountains early and often and get back to us with how much it saves.

jack vines
It is Neutral in the sense that the car rolls freely with only the resistance of a few spinning hunks of inert metal. I am not advocating for coasting. I think it is foolish and pointless. And yes, I think I was the first to point out the lack of lubrication.
 
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