Driving in B mode often can cause issues?

[zanzabar]

I fail to understand why bother with regen.

One pedal driving obviously! I like not having to move my foot over to the brake pedal if I don't have to.

 

[mpulsiv]

I fail to understand why bother with regen.

One pedal driving obviously! I like not having to move my foot over to the brake pedal if I don't have to.

Makes sense. There are slew of drivers with 3 pedals nostalgia. The technology is reducing user interaction
On a relevant note, I still think that new drivers should learn to drive a stick. This is the most effective learning curve to feel the car and stay relaxed. Majority of drivers behind the wheel are way too tense. Tension leads to fear. With all the technology at our disposal, drivers still stuck in 2-dimensional world. 97% of their attention is through the windshield. Anyways, I have no intension to derail discussed topic. Just wanted to chime in about driver awareness and interaction as we shift into the future with 1 pedal driving :mrgreen:

 

[Szyszka]

I fail to understand why bother with regen. After all, your brake pads don't come into play until your braking demand exceeds the stopping force of the regen system. As soon as you touch the brake pedal, regen kicks in sequential order: D1 -> D2 -> D3 -> B -> your brake pads. So, why bother?

On a different note, here's the screenshot from the owner's manual. If I understand this correctly, we must take foot off the pedal when switch drive modes (e.g. D1, D2, D3, B) due delay in re-calibration. Please chime in.

I am by no means regen braking expert but do not agree with the sequence you provided ( "As soon as you touch the brake pedal, regen kicks in sequential order: D1 -> D2 -> D3 -> B -> your brake pads). When you touch the brake pedal, you DO START engaging the brake pads. On the contrary, brakes are NOT used when slowing using any of the four regen modes (D1, D2, D3, and B).

As for your understanding of the manual, again, I think you're reading it incorrectly. The note about not accelerating when moving the selector surely applies to the 'move' between P, R, N, and D. I would argue that switching between D and D1/D2/D3 and B modes are precisely that: 'switches' and the annotation you're reading has nothing to do with those.

 

[f1geek]

When you press on the brake pedal, the brake pads will not engage unless the deceleration you require (indicated by how hard you press the pedal) is greater than can be provided by regen. The e-Golf has a blended regen/frction braking system and will only engage friction brakes (pads) when the computer senses you can't stop fast enough via regen. There is no sequence of D3-D2...etc. Those driving mode are for the level of regen you get when you lift your foot off the accelerator pedal - those mode have nothing do do with the brake pedal.

As far as moving the shift level during acceleration, I move the level from D to B or left or right all the time, including when accelerating and decelerating. I haven't noticed any loss of control, though I am only pulling it back or moving it left or right.

 

[mpulsiv]

I think this is somewhat accurate. Watch the needle when you hit the brake to determine if your brake pads come into play.
Needle can fluctuate based on terrain when coasting downhill.

 

[JoulesThief]

I can regenerate clear to the 6th mark in the green, the limit, putting the car in D3 coming down a 6% grade at 65 mph, without touching the brake pedal. A lot of it depends on how fast you are travelling when you apply the various D modes or B mode.

 

[in2insight]

I drive mostly in D2, sometimes in B.
Question, when shifting from B back to D why does the shifter go to N first?
I tried to find the answer in the manual, but came up short.

Wait, how are you shifting from B to D? You're supposed to tap it backward, not forward. Are you pushing it forward and therefore into N?

(Bows head in shame) Yes, I was pushing forward. Thank you for kindly giving me the correct way to do so.

 

[mpulsiv]

I find interesting how rear brakes are more engaged just by observing the brake dust. I'm seeing way more dust in the rear :shock:
Typically, rear brakes on ICE cars are used ~30% and exhibit way less dust compared to front brakes.

 

[f1geek]

My e-Golf has almost no front brake dust on the wheels ( I just hand washed the car and had a very close look at the wheels). Rear wheel brake dust is caused by low speed stopping, and VW has a rear brake bias for very low speed brake usage, as also evidenced by brake sound coming from the rear of car at ~5 mph or less stopping. Front brakes show very little dust because almost no braking is done by front brakes any speed (unless you panic brake at highway speeds). This is why I don't believe the whole D3-D2-D1, etc. regime is correct - I think the friction brakes don't get applied unless the needle is pegged at max "green" and the brake pedal pressure indicates to the computer more deceleration is needed.

 

[JoulesThief]

I think the friction brakes don't get applied unless the needle is pegged at max "green" and the brake pedal pressure indicates to the computer more deceleration is needed.

/\ This is correct. I almost never get brake dust on either front or rear wheels, as noted when washing the car and the rims. Early on in ownership, I took the e-Golf through the twisty canyon roads here and did use the brake somewhat aggressively, pegging the needle in the green, and sure enough, I would have to scrub the brake dust off of rear wheels on the next car wash.

This was valving and setup on a 2015... I do not know if they've changed the valving on newer 2019's.

You do have to peg the needle in the green, going counter clockwise, and then push on the brakes just bit more to get that rear brake dust.

 

[msvphoto]

I think the friction brakes don't get applied unless the needle is pegged at max "green" and the brake pedal pressure indicates to the computer more deceleration is needed.

/\ This is correct. I almost never get brake dust on either front or rear wheels, as noted when washing the car and the rims. Early on in ownership, I took the e-Golf through the twisty canyon roads here and did use the brake somewhat aggressively, pegging the needle in the green, and sure enough, I would have to scrub the brake dust off of rear wheels on the next car wash.

This was valving and setup on a 2015... I do not know if they've changed the valving on newer 2019's.

You do have to peg the needle in the green, going counter clockwise, and then push on the brakes just bit more to get that rear brake dust.

Wait, what?! You were canyon carving in your eGolf?! I'm guessing that wasn't a 6mi/kWh day?

 

[Szyszka]

I think the friction brakes don't get applied unless the needle is pegged at max "green" and the brake pedal pressure indicates to the computer more deceleration is needed.

/\ This is correct.

No, it is not! Brakes engage at any time you hit the brake pedal and you absolutely do not have to be in the max "green" area to use them. Are you guys seriously not feeling your brakes engaging??? It is a very different feeling from the regenerative braking offered by the electric motor.

 

[JoulesThief]

I think the friction brakes don't get applied unless the needle is pegged at max "green" and the brake pedal pressure indicates to the computer more deceleration is needed.

/\ This is correct. I almost never get brake dust on either front or rear wheels, as noted when washing the car and the rims. Early on in ownership, I took the e-Golf through the twisty canyon roads here and did use the brake somewhat aggressively, pegging the needle in the green, and sure enough, I would have to scrub the brake dust off of rear wheels on the next car wash.

This was valving and setup on a 2015... I do not know if they've changed the valving on newer 2019's.

You do have to peg the needle in the green, going counter clockwise, and then push on the brakes just bit more to get that rear brake dust.

Wait, what?! You were canyon carving in your eGolf?! I'm guessing that wasn't a 6mi/kWh day?

I was being pushed, early on, by a very young man with a very loud fart canned Honda Civic that had the suspension coils cut and a tow bar hitch with a pair of bulls balls almost dragging of the back of it, on my butt, before I passed him. Then I got tired of not seeing his headlights in the rear view mirror... he was too close behind me, so, he kind of forced my hand to see if I could walk away from him. I knew he was enjoying pushing me when I made a right turn off of Las Virgenes Cyn Rd, heading east onto Mullholland highway and he followed me.

Yes, I really crapped up my miles per kWh on that particular trip. Not proud of it, but I got rid of the little 10,000 rpm screamer, finally. I think I barely made 2.6 miles per kWh showing on that "trip" My battery was full in Malibu, and below half when I got home. I know it's about 27 or 28 miles one way for that trip, and 960 feet of elevation gain. The Econo needle got pegged a lot at both ends of the blue and green scale that night.

 

[msvphoto]

I think the friction brakes don't get applied unless the needle is pegged at max "green" and the brake pedal pressure indicates to the computer more deceleration is needed.

/\ This is correct.

No, it is not! Brakes engage at any time you hit the brake pedal and you absolutely do not have to be in the max "green" area to use them. Are you guys seriously not feeling your brakes engaging??? It is a very different feeling from the regenerative braking offered by the electric motor.

I most certainly can feel the difference between regen only and friction but VW does a very good job at blending the two. If you lightly touch the brake pedal it is regen only. The feel is in the pedal itself (you feel hydraulic pressure in your foot). In normal driving almost all braking is regen unless a panic stop. In my experience in normal driving only the last few MPH are friction. I just had all four wheels off our eGolf for the first time since we bought and did a brake inspection. At ~51k miles the pads and rotors still look pretty much new, as in what I would expect to see with a tenth of the milage on an ICE car. There is more friction braking right after a 100% charge, but that goes away in just a few miles. The programming for the brake pedal is obviously regen first and friction only when needed (determined by how hard the pedal is pressed).

Personally, I like coasting unless descending long grades so I drive in D all the time and use D1 - D3 to control speed down long grades such as Hwy 17 between Santa Cruz and San Jose.

 

[Szyszka]

I most certainly can feel the difference between regen only and friction but VW does a very good job at blending the two. If you lightly touch the brake pedal it is regen only. The feel is in the pedal itself (you feel hydraulic pressure in your foot). In normal driving almost all braking is regen unless a panic stop.

I am so sorry to keep at this but how can you be 100% certain that this is indeed the case? I am talking specifically about this: "If you lightly touch the brake pedal it is regen only." Could you back this point by concrete examples?

I would argue that touching the brake pedal - 1) places the electric motor in the regen mode but also 2) engages the traditional brakes, like any other standard, hydraulic braking system on the ICE car. The sole reason for the existence of standard braking system on the EV cars is that the regen braking alone is not cable of stopping the car on its own. I really don't think there is anything magical about the 'standard' braking system in the e-Golf; particularly at the level that would allow the driver to keep pressing the brake pedal and yet not to engage the hydraulic system designed to operate the system.

The second statement you make "In normal driving almost all braking is regen unless a panic stop." is only true if you keep your car in any of the regen modes available (D1, D2, D3 or B) and never use the brake pedal.

It goes without saying that the standard braking system on any EV is not taxed as much as on an ICE car, hence it is not really unusual to see very little wear on the pads as you have yourself discovered.

 

[f1geek]

Sorry, but you are just plain wrong.

Please watch this VW video which explains what I have been saying: in the e-Golf (not necessarily in other EVs), first you get regen (and ONLY regen) and only when regen can't provide the necessary stopping power, do the friction brakes kick in. This system is one reason why the e-Golf is so efficient.

https://www.youtube.com/watch?v=nE4T2YB0nV4&feature=youtu.be

To learn more details about VW e-Golf regenerative braking technology, this is a good site.

https://www.volkswagen.co.uk/electric/technology/regenerative-braking

 

[JoulesThief]

Sorry, but you are just plain wrong.

Please watch this VW video which explains what I have been saying: in the e-Golf (not necessarily in other EVs), first you get regen (and ONLY regen) and only when regen can't provide the necessary stopping power, do the friction brakes kick in. This system is one reason why the e-Golf is so efficient.

https://www.youtube.com/watch?v=nE4T2YB0nV4&feature=youtu.be

To learn more details about VW e-Golf regenerative braking technology, this is a good site.

https://www.volkswagen.co.uk/electric/technology/regenerative-braking

I would allude to the fact that brake dust on the rims is almost non existent between car washes, for me. If my brakes are being used and activated, there should be brake pad dust on the rims. Maybe the rims are sooooo aerodynamic that they shed brake dust too?

Just sharing my observations. it takes a good bit of pressure in D3 at 55 -60 mph to peg the needle counterclockwise on the green side, to the 6th bar. It is so rare or unusual for me, that it explains the June Gloom annual fog we have here, and if the car sits for a few days, the rotors will make a very slight scuffing sound, that usually only a hard, fast brake application will remove, and get rid of the sound, wiping the rotors clean of the rust film.

 

[msvphoto]

I most certainly can feel the difference between regen only and friction but VW does a very good job at blending the two. If you lightly touch the brake pedal it is regen only. The feel is in the pedal itself (you feel hydraulic pressure in your foot). In normal driving almost all braking is regen unless a panic stop.

I am so sorry to keep at this but how can you be 100% certain that this is indeed the case? I am talking specifically about this: "If you lightly touch the brake pedal it is regen only." Could you back this point by concrete examples?

I would argue that touching the brake pedal - 1) places the electric motor in the regen mode but also 2) engages the traditional brakes, like any other standard, hydraulic braking system on the ICE car. The sole reason for the existence of standard braking system on the EV cars is that the regen braking alone is not cable of stopping the car on its own. I really don't think there is anything magical about the 'standard' braking system in the e-Golf; particularly at the level that would allow the driver to keep pressing the brake pedal and yet not to engage the hydraulic system designed to operate the system.

The second statement you make "In normal driving almost all braking is regen unless a panic stop." is only true if you keep your car in any of the regen modes available (D1, D2, D3 or B) and never use the brake pedal.

It goes without saying that the standard braking system on any EV is not taxed as much as on an ICE car, hence it is not really unusual to see very little wear on the pads as you have yourself discovered.

Yes, I am 100% certain based on extensive enthusiast driving experience that spans more than 4 decades, a motorsports journalist for nearly 2 decades, a DIY mechanic for more than 4 decades who has owned and maintained more than 50 vehicles and driven countless more. Any experienced driver can feel pad engagement with their foot. In the days before ABS drivers were extra tuned in because that foot was the ABS.

The brake pedal has a range of motion. Drive an ICE car. Do the brakes engage the moment you touch the pedal? No. Do they engage even the first inch or two of pedal travel? No. On an eGolf does regen start the moment the pedal movement is sensed by the brake pedal sensor regardless of driving mode selected? Absolutely. (I say sensor because I suspect it is just like a fly-by-wire accelerator pedal sensor.) Does the pedal have a nice firm "pads engaged hydraulically" feel when pressed to that point? Yes, and a very nice pedal feel I might add. It is that point at which the pads would normally engage on an ICE car that they also engage on an eGolf. However, in normal driving (read safe distance controlled stops) seldom do you need to press the pedal all the way to pad engagement until the car is almost at a full stop. The vast majority of speed reduction is regen, regardless of driving mode.

An essentially new looking brake system after over 50k miles of driving should be enough of a "concrete example."

Actually your last paragraph sums it up nicely, although I would change "not taxed as much" to "taxed much less."

 

[Szyszka]

Yes, I am 100% certain based on extensive enthusiast driving experience that spans more than 4 decades, a motorsports journalist for nearly 2 decades, a DIY mechanic for more than 4 decades who has owned and maintained more than 50 vehicles and driven countless more. Any experienced driver can feel pad engagement with their foot. In the days before ABS drivers were extra tuned in because that foot was the ABS.

The brake pedal has a range of motion. Drive an ICE car. Do the brakes engage the moment you touch the pedal? No. Do they engage even the first inch or two of pedal travel? No. On an eGolf does regen start the moment the pedal movement is sensed by the brake pedal sensor regardless of driving mode selected? Absolutely. (I say sensor because I suspect it is just like a fly-by-wire accelerator pedal sensor.) Does the pedal have a nice firm "pads engaged hydraulically" feel when pressed to that point? Yes, and a very nice pedal feel I might add. It is that point at which the pads would normally engage on an ICE car that they also engage on an eGolf. However, in normal driving (read safe distance controlled stops) seldom do you need to press the pedal all the way to pad engagement until the car is almost at a full stop. The vast majority of speed reduction is regen, regardless of driving mode.

An essentially new looking brake system after over 50k miles of driving should be enough of a "concrete example."

Actually your last paragraph sums it up nicely, although I would change "not taxed as much" to "taxed much less."

Thanks for that explanation!

 

[zanzabar]

..., and VW has a rear brake bias for very low speed brake usage, ...

This fits with my experience too, I've done many brake jobs on A3/A4/B5 platforms and always find that rear pads wear about 2x faster than front pads. Seems logical that they would continue that on to later generations and the e-Golf.