msvphoto
Posts: 196
Joined: Mon Nov 20, 2017 12:30 pm

Re: Driving in B mode often can cause issues?

Thu Nov 07, 2019 10:22 am

JoulesThief wrote:
Thu Nov 07, 2019 8:45 am
f1geek wrote:
Tue Nov 05, 2019 5:58 pm
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? :D
2015 e-Golf SEL my wife's daily, shared on weekends
2000 BMW 540iT my daily and our range extender
1986 Audi 4000 quattro "the cockroach" my alternate daily
1983 Audi Ur Quattro "the garage queen" looks pretty and appreciates daily

Szyszka
Posts: 71
Joined: Fri Sep 06, 2019 8:31 am

Re: Driving in B mode often can cause issues?

Thu Nov 07, 2019 10:41 am

JoulesThief wrote:
Thu Nov 07, 2019 8:45 am
f1geek wrote:
Tue Nov 05, 2019 5:58 pm
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
Posts: 2576
Joined: Mon Oct 05, 2015 2:01 pm

Re: Driving in B mode often can cause issues?

Thu Nov 07, 2019 4:13 pm

msvphoto wrote:
Thu Nov 07, 2019 10:22 am
JoulesThief wrote:
Thu Nov 07, 2019 8:45 am
f1geek wrote:
Tue Nov 05, 2019 5:58 pm
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? :D
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.
2015 e-Golf SEL
2015 Passat TDI SEL
2014 Touareg TDI LUX

Full spectrum VW owner, life is too short to wait to drive for a recharge.

msvphoto
Posts: 196
Joined: Mon Nov 20, 2017 12:30 pm

Re: Driving in B mode often can cause issues?

Thu Nov 07, 2019 4:15 pm

Szyszka wrote:
Thu Nov 07, 2019 10:41 am
JoulesThief wrote:
Thu Nov 07, 2019 8:45 am
f1geek wrote:
Tue Nov 05, 2019 5:58 pm
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.
2015 e-Golf SEL my wife's daily, shared on weekends
2000 BMW 540iT my daily and our range extender
1986 Audi 4000 quattro "the cockroach" my alternate daily
1983 Audi Ur Quattro "the garage queen" looks pretty and appreciates daily

Szyszka
Posts: 71
Joined: Fri Sep 06, 2019 8:31 am

Re: Driving in B mode often can cause issues?

Thu Nov 07, 2019 7:31 pm

msvphoto wrote:
Thu Nov 07, 2019 4:15 pm
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
Posts: 918
Joined: Fri Jan 23, 2015 1:18 pm
Location: SF Bay Area

Re: Driving in B mode often can cause issues?

Thu Nov 07, 2019 10:10 pm

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=nE4T2YB ... e=youtu.be

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

https://www.volkswagen.co.uk/electric/t ... ve-braking
2017 e-Golf LE, Multi Coat White with Black Vegan Leather interior

JoulesThief
Posts: 2576
Joined: Mon Oct 05, 2015 2:01 pm

Re: Driving in B mode often can cause issues?

Fri Nov 08, 2019 8:51 am

f1geek wrote:
Thu Nov 07, 2019 10:10 pm
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=nE4T2YB ... e=youtu.be

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

https://www.volkswagen.co.uk/electric/t ... ve-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.
2015 e-Golf SEL
2015 Passat TDI SEL
2014 Touareg TDI LUX

Full spectrum VW owner, life is too short to wait to drive for a recharge.

msvphoto
Posts: 196
Joined: Mon Nov 20, 2017 12:30 pm

Re: Driving in B mode often can cause issues?

Fri Nov 08, 2019 9:30 am

Szyszka wrote:
Thu Nov 07, 2019 7:31 pm
msvphoto wrote:
Thu Nov 07, 2019 4:15 pm
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."
2015 e-Golf SEL my wife's daily, shared on weekends
2000 BMW 540iT my daily and our range extender
1986 Audi 4000 quattro "the cockroach" my alternate daily
1983 Audi Ur Quattro "the garage queen" looks pretty and appreciates daily

Szyszka
Posts: 71
Joined: Fri Sep 06, 2019 8:31 am

Re: Driving in B mode often can cause issues?

Fri Nov 08, 2019 11:41 am

msvphoto wrote:
Fri Nov 08, 2019 9:30 am
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
Posts: 38
Joined: Tue Jun 04, 2019 12:46 pm
Location: Petaluma, CA

Re: Driving in B mode often can cause issues?

Wed Nov 13, 2019 11:43 am

f1geek wrote:
Tue Nov 05, 2019 5:58 pm
..., 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.
His: 2007 Volvo V70 (185k miles)
Hers: 2019 e-Golf SE (11k miles, black, all stock)
Former: 2016 e-Golf SE (silver, lowered on H&R Sport springs, 225/55 tires on 16" Konig wheels [sold])

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