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... That's basically the question I've been asking. If you stomp on the pedal in "D" mode, what's the maximum shown on the display? ...
It seems like such a simple question - what am I missing?
It is a simple question.

Any 'concerns' about the friction brakes blending in can be tested with a cheap IR reader pointed at the discs after a stop.

Find a quiet road/highway at a time when you know you have not activated the friction brakes in a while.
Come to a stop at ~68kW, pull to the shoulder, flashers on and hop out and take a quick temp reading from the discs.

I like to call this "Normal Driving" !:p (Yo, Josh..)
I requires NO last minute decisions about moving your foot from one pedal to the other during braking.

You get coast. You don't have to keep your foot planted for the entire trip. No adopting a "New Driving Style", etc.
(Brand T does not offer this!)

I really question Chevy making efficiency claims of 5-15% better in L.
If the Accel rates, the cruise speeds and the Decel rates are the same,, why would there be any differences?
 

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Discussion Starter #25
I really question Chevy making efficiency claims of 5-15% better in L.
If the Accel rates, the cruise speeds and the Decel rates are the same,, why would there be any differences?
This is exactly why I want to find out how much regen you get in "D" mode. With the discussion of the differences between the braking system on the Bolt EV vs. the Volt, I'm suspecting that using the brake pedal on the Bolt will start to engage the friction brakes before reaching full regen, and it might not even reach full regen with the brake pedal alone. In that case, you'd be better off driving in "L" mode since you'd be guaranteed of never using the friction brakes unless you had to decelerate so strongly that you need to use the brake pedal.
 

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This is exactly why I want to find out how much regen you get in "D" mode.
Me too. It's such a simple question. Regen in D with no friction brakes.
Yet Chevy marketing/Eng. PR seems to have gone down the path of chasing the T brand, or at least talking that way.

All that is needed is a $20 IR temp gun: https://smile.amazon.com/Digital-Infrared-Thermometer-Non-contact-Temperature/dp/B01GCFEGVA/ref=sr_1_2?s=hi&ie=UTF8&qid=1485137604&sr=1-2-spons&keywords=ir+temperature+gun&psc=1
Has uses in the kitchen and outdoor grill too !!:cool:

It's not too hard for a Bolt owner to answer this simple question.
 

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It seems like such a simple question - what am I missing?
Traffic :) Most of the time if you are stomping on the brake pedal you are paying attention to what is outside your windshield, not what is on the dash display. I would say that the only people doing testing right now drive most of the time in low, and have not gotten around to testing high speed brake pedal use in D yet :)

I have a theory about increased efficiency in L vs D... (theory only, no data to back it up). When driving it is common to brake harder than you need to when you start slowing down, and then ease off of the brake pedal as you get closer to the point where the car actually needs to come to a stop. If you do this in D, you "probably" engage the friction brakes when they are not actually needed. When driving in low with very aggressive regeneration, just taking your foot off of the "go" pedal gives rapid deceleration, and you are unlikely to move your foot over to the brake pedal, and if you do feel the need for more deceleration you use the "regen on demand" padel rather than pressing the brake... the brake pedal almost becomes and "emergency use only" pedal.

Later,

Keith
 

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It's not too hard for a Bolt owner to answer this simple question.
Max regen in D without using regen paddle: 50 kW
Max regen in L without paddle: 50 kW
Max in D or L using the paddle: 70 kW

 

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Max regen in D without using regen paddle: 50 kW
Max regen in L without paddle: 50 kW
Max in D or L using the paddle: 70 kW

And Thank You so much!!!

It's just that there is this FEAR of using the friction brakes when in D. At least for some..

The question might remain: Is there any brake disc heating going on when braking in D up to and near that 50kW number on the display?

I suspect not, but Chevy was so evasive with talking about blended brakes on the Bolt that there is this question....

I'm not concerned too much. A Bolt is in my future but not for a while. I'm living the dream in my (faster than a Bolt at DCFC'ing) Spark EV !!!:D Haa, couldn't resist...
 

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Max regen in D without using regen paddle: 50 kW
Max regen in L without paddle: 50 kW
Max in D or L using the paddle: 70 kW
Thanks for the info. Please help me understand the test conditions.

What SoC was the battery at during this testing?
Please confirm these max's were created by pressing the brake pedal, not simply lifting the accelerator.
Were you going downhill or decelerating from a particular speed when you hit these maxes?
 

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Thanks for the info. Please help me understand the test conditions.

What SoC was the battery at during this testing?
Please confirm these max's were created by pressing the brake pedal, not simply lifting the accelerator.
Were you going downhill or decelerating from a particular speed when you hit these maxes?
SOC was around 50-60%.
50 kW achieved by using the brakes....at least in D. Not sure about L.
Was going downhill around 50-60 mph when I started slowing each time.
 

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Max regen in D without using regen paddle: 50 kW
Max regen in L without paddle: 50 kW
Max in D or L using the paddle: 70 kW
I think you were over the SOC cutoff, because I was able to achieve 65 kW in D using the brake pedal.

Also, I'm going to have to adjust my early assessment of high SOC regenerative braking. Even with only ~ 2 kWh used, I was seeing > 30 kW of regenerative braking in L. Over ~ 5 kWh used, I was seeing 40 kW of regenerative braking. I don't know what the exact map is, but regenerative braking ramps up very aggressively.
 
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