E-Pedal Verses B Mode

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DaveinOlyWA

Well-known member
Joined
Apr 24, 2010
Messages
16,260
Location
Olympia, WA
Had to write this due to several lengthy discussions that eventually went....nowhere. If you don't care about the numbers, then skip to the last 2 paragraphs. I contend that B mode is unsafe and that needs to be fixed. Until then, I will only use E-Pedal (which is pretty much what I have always done anyway ;) )



https://daveinolywa.blogspot.com/2018/11/e-pedal-verses-b-mode.html
 
You may as well remove this:

"This blog is NOT intended to say one mode over another is the best."

Since you keep claiming just that. You might also lose three or four of the unnecessary exclamation points. Finally, the "unsafe" claim doesn't seem to be documented, or even explained. This is why I don't generally read blogs.
 
LeftieBiker said:
You may as well remove this:

"This blog is NOT intended to say one mode over another is the best."

Since you keep claiming just that. You might also lose three or four of the unnecessary exclamation points. Finally, the "unsafe" claim doesn't seem to be documented, or even explained. This is why I don't generally read blogs.

So using B mode as primary speed control without brake lights is ok to you?


Truth be told; the modes all do the same thing, just with varying levels of distance and time. Regen is 100% controllable in all modes.
There is even an Eco button if you want assistance. But E-Pedal provides a much greater level of regen even at street speeds as the logs show. What does that mean? In an emergency stop, probably no more than a few feet. I guess if you never need that few feet, you have nothing to worry about.

As for intent; I implied the intent was to determine how efficient each mode is but truth be told, it really is all about safety. If you have ever been behind someone without brake lights in heavy traffic, you would know how I feel.
 
I'm guessing that you have never regularly driven a car with a manual transmission. Driving in an urban setting in 1st or 2nd is exactly like using B mode. No brake lights, lots of deceleration. I agree that it might be better to have them, but this is hardly the HUGE! SAFETY! ISSUE! you seem to think. As for ePedal: I use it occasionally, but don't really like it.
 
Dave,

A taxi driver I met in Amsterdam, so a professional urban driver, only drives in E-pedal. He liked it enough to specifically mention it when I quizzed him about the new Leaf.

In our Bolt, I only drive in "L" and will on occasion resort to the paddle as well. I do put my foot on the brake pedal at stop lights to illuminate the brake lights. Yes, it's not legally necessary but around here it's a good idea. ;)

Paul
 
LeftieBiker said:
I'm guessing that you have never regularly driven a car with a manual transmission. Driving in an urban setting in 1st or 2nd is exactly like using B mode. No brake lights, lots of deceleration. I agree that it might be better to have them, but this is hardly the HUGE! SAFETY! ISSUE! you seem to think. As for ePedal: I use it occasionally, but don't really like it.

Yeah, tons of manual transmission cars sold every year nowadays. Personally I don't understand your position. Do you feel the current rate of accidents is acceptable because "its always been that way" ?

I also think its important to note that slowing down by downshifting on a manual tranny is not recommended. But then again, we just started wearing seat belts how long ago?
 
paulgipe said:
Dave,

A taxi driver I met in Amsterdam, so a professional urban driver, only drives in E-pedal. He liked it enough to specifically mention it when I quizzed him about the new Leaf.

In our Bolt, I only drive in "L" and will on occasion resort to the paddle as well. I do put my foot on the brake pedal at stop lights to illuminate the brake lights. Yes, it's not legally necessary but around here it's a good idea. ;)

Paul

Oh course the taxi driver would love it. Taxi drivers do whatever they can to be visible so an overactive brake light is exactly what they are looking for!

Accidents (even ones that are their fault) can be very expensive in more ways than one so if it prevents one 5 mph rear ender, its worth a hundred extra charges
 
Yeah, tons of manual transmission cars sold every year nowadays. Personally I don't understand your position. Do you feel the current rate of accidents is acceptable because "its always been that way" ?

I also think its important to note that slowing down by downshifting on a manual tranny is not recommended. But then again, we just started wearing seat belts how long ago?

Sloppy writing I can tolerate. Sloppy reasoning and sloppy arguing are worse. Do you have any idea whatsoever how many accidents are caused solely by drivers slowing in a low gear, with no brake lights on? Any whatsoever? If you had driving experience with a manual transmission, you would understand that normal city driving involves regularly slowing in gear without the brakes on until actually stopping. Aside from the usual CYA, the manuals you reference are talking about slowing from highway speeds, not about urban driving at low speeds. Your whole idea that B mode is dangerous is based on a lack of understanding of how people drive millions of cars and (especially lately) trucks every day. The sky isn't falling, and while well-programmed B/L mode brake light activation would be nice, it isn't quite as urgent as you seem to believe. Much, much less urgent than the use of seat belts.
 
DaveinOlyWA said:
I also think its important to note that slowing down by downshifting on a manual tranny is not recommended. But then again, we just started wearing seat belts how long ago?
Downshifting isn't recommended? By whom? I think people don't downshift enough! Have you ever been in a passenger vehicle that has lost it's brakes on a steep downhill grade do to not engine braking? I have (I wasn't the driver.) Have you ever had a vehicle that after 30 years still had it's original brake pads, shoes, rotors and drums and they still looked new while the neighbor's needed changed every 6 months? I have.

Why do people say downshifting is only a manual transmission thing? I downshift all the time in my automatics. Right now I'm loving the 6 levels of "downshifting" my Avalon Hybrid gives me, and I use them all.

Who's at fault in a rear ender? The one that was tail-gating or the one who downshifted? The one who was tail-gating of course. So why blame the guy who is engine braking or regenerating without brake lights? People need to give the next car some space. If it starts to slow down, then slow down and maintain that space. Don't wait for brake lights to come on. If you can't do that then expect to rear-end someone some day.

Now don't get me wrong. I see a benefit in brake lights lighting up for any sort of deceleration. But I also see some issues with it. First, when going down a hill behind a car that turns it's brake lights on anytime it's downshifted or regenerating then there's no way to know when the car may want to actually stop, or if it's going to keep going the same speed. I guess this could be remedied by adding varying levels of brake lights, or make them flash for more forceful braking. But second, then how do you apply the same technology to all cars? Nearly all cars have the ability to downshift. Anyone who wants to can move that lever down and get engine braking action without lighting up the brake lights.

Before the Leaf and the Avalon I had an old 23:1 CR VW diesel that engine-braked more forcefully than the B mode on the Leaf. I often thought of hooking up the idle switch (a switch that turned off the upshift indicator light when the throttle was at idle) to a blinker module that could blink the brake lights on and off when engine braking. I have always been personally aware of people behind me not seeing brake lights come on. So in the Leaf and every other vehicle I've had I simply and lightly tap the brake pedal a few times when I go to downshift so as to alert them of my intentions.

I think the way this is going is that cars are starting to have automatic braking and automatic distancing technology. So some day law makers may make it a must that all new cars have such technology. Then if the next person lets up off the pedal in B mode or whatever, the cars behind will automatically adjust their speed.

Here's another story about downshifting. I worked as a school bus driver in Colorado for 5 years. The mechanic told me that in his many years being a mechanic there he never needed to replace bus brake shoes or drums from wearing out. The only time he had to replace a few was when the bearing seal failed and contaminated the brake linings. He attributed this to the bus drivers being good about downshifting. But with the company cars the teachers would take it was another story. Since the teachers weren't trained driving professionals, they would come back with warped rotors EVERY TIME they went over a mountain pass. The mechanic got to the point he installed oversized slotted and drilled rotors and ceramic brake pads on all the company cars so he wouldn't need to replace them so often.
 
Back when I was a teen I got a Class I permit so I could drive a big car transporter for a guy employing me to drive extra auction cars home. I only drove the giant truck a few times, but it was impressed very firmly on me that "you can't use the brakes to slow it!" You HAD to downshift and use engine braking, because the friction brakes would get worn out very, very quickly, or even fail on the road from heat, from slowing the truck too much. This still largely applies, so all of those tractor-trailers on the highways are being slowed almost all of the time by downshifting, not by the brakes. AFAIK they have no brake light activation when it happens. And yes, Isaac is right: when a car slowing at anything less than wheel-locking speed gets rear-ended, it's the fault of the driver behind.
 
Here's one for you. Many, if not most new automatic cars and trucks automatically downshift when going down hills. Yet the brake lights do not light up when this happens.

My thoughts is that B mode is for going down steep hills, like when you downshift for engine braking. And E-Pedal is for anything other than going down hills. I would think following a Leaf going down a hill with it's brake lights on constantly from using the E-Pedal would be confusing.
 
I personally use epedal all the time but I don’t like the brake lights coming on under such light regen conditions. Makes me look like I ride the brakes and don’t know how to drive.

If you get rear ended, it has everything to do with the idiot behind you following too close and not paying attention.

It is always recommended to use the engine to slow a vehicle over the brakes. As brakes heat up their performance degrades. A good defensive driver, their brakes will have issues related to calipers seizing up but otherwise lasting an exceptionally long time.

Dave, you’re a fear monger.
 
NavyCuda said:
I personally use epedal all the time but I don’t like the brake lights coming on under such light regen conditions. Makes me look like I ride the brakes and don’t know how to drive.

If you get rear ended, it has everything to do with the idiot behind you following too close and not paying attention.

It is always recommended to use the engine to slow a vehicle over the brakes. As brakes heat up their performance degrades. A good defensive driver, their brakes will have issues related to calipers seizing up but otherwise lasting an exceptionally long time.

Dave, you’re a fear monger.


I think a lot of opinion on this is based on personal circumstances. FYI; WA drivers DON'T know how to drive. We were ranked 178th AFTER discounting for weather conditions so can't even use rain as an excuse.

As far as brake lights flashing on and off. Its rather common here for people to ride the brakes without slowing down if they see something ahead due to the huge number of rear enders we have here.
 
I came across this thread after test driving a 2018 LEAF last night. Was basically surprised to not see any brake lights in either b or e-pedal mode.

Having driven commercial buses for over 30 years, I can’t believe this is DOT legal. Apply any type of engine brake or transmission retarder on a commercial bus will light the brake lights. The transit authority where I currently work installed deceleration lightning on every bus, works off a gyroscope switch and lights an extra set of amber lights when slowing.

Not having a similar device on a LEAF is both stupid and dangerous.
 
The leaf is my first "automatic" transmission vehicle and I use B-mode exactly like I used engine braking on a 5-speed. While I do understand the position of the OP, and could understand having the brake lights come on under a certain level of regen, I would hate it if the brake lights came on every time I lifted or modulated the throttle in B-mode. It would cause a lot of unnecessary braking by the people around me and would make me look like a clown with the brakes lights flickering on and off all the time. If I need to slow down considerably or stop I hit the brake pedal, if anyone hits me while I'm using B-mode to modulate my speed they are either not paying attention, driving way to close, or both IMO.
 
rogersleaf said:
I came across this thread after test driving a 2018 LEAF last night. Was basically surprised to not see any brake lights in either b or e-pedal mode.

Having driven commercial buses for over 30 years, I can’t believe this is DOT legal. Apply any type of engine brake or transmission retarder on a commercial bus will light the brake lights. The transit authority where I currently work installed deceleration lightning on every bus, works off a gyroscope switch and lights an extra set of amber lights when slowing.

Not having a similar device on a LEAF is both stupid and dangerous.

You "mis saw" there is definitely brake lights in E Pedal. For all other drive modes, only the brake pedal actuates the brake lights.
 
golfcart said:
The leaf is my first "automatic" transmission vehicle and I use B-mode exactly like I used engine braking on a 5-speed. While I do understand the position of the OP, and could understand having the brake lights come on under a certain level of regen, I would hate it if the brake lights came on every time I lifted or modulated the throttle in B-mode. It would cause a lot of unnecessary braking by the people around me and would make me look like a clown with the brakes lights flickering on and off all the time. If I need to slow down considerably or stop I hit the brake pedal, if anyone hits me while I'm using B-mode to modulate my speed they are either not paying attention, driving way to close, or both IMO.

I would hate it too. Thankfully that is not how E Pedal works. It actuates brake lights only when it hits a certain level of deceleration and they remain on until you start to accelerate again.
 
DaveinOlyWA said:
I would hate it too. Thankfully that is not how E Pedal works. It actuates brake lights only when it hits a certain level of deceleration and they remain on until you start to accelerate again.

Yeah but I was talking about brake lights while using B-mode. If that is what you are advocating for with B-mode then I could live with it. I would lose the ability to mess with tailgaters on the highway but I suppose that's a small price to pay for safety. :D
 
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