M3 equivalent "Econ" or Regenerative Braking modes?

[dgpcolorado]

...Its pretty easy to get used to it driving around town, once you get the stopping distance under control. What's hard to remember is coming off of cruise control on the highway. If you normally tap the brake to disable cruise control, that habit will lead to some non-smooth driving as the heavy regen kicks in at freeway speeds. I have to remember to put my foot on the gas pedal and press it down, THEN turn off cruise with the button.


Overall from what I have seen on the S forums, you either love one-pedal driving right away, or you manage to get used to one-pedal driving, but never fully enjoy it.

Just so. You need to put your foot back on the go pedal before defeating cruise. With a bit of practice it can be done fairly seamlessly and it becomes habit. If you really do want to slow quickly then hitting the brakes will do it and the brake lights will come on with any rapid slowing, brake pedal or not.

For those of us with manual transmission experience, it isn't any more difficult that learning to downshift but for those used to automatics it will be a new skill.

 

[eisbock]

In my car - Acura RSX, when cruise control is activated, the acceleration pedal will be loose up to the point where it's depressed for the cruise speed. So I can basically tap the pedal and not apply so much pressure and have it right where it's positioned for throttling. For an example for better understanding: If the cruise control is using about 50% throttle (OBD2 monitoring can tell you this), and the pedal is at maybe 30-50%, I would have my foot pressed up to the 50% position, turn off the cruise, and there will be a smooth transition where there's no jerk from disabling cruise control.

Yes, that's exactly how my car drives too. Just enough pressure to get past the "looseness" and it's smooth-sailing.

 

[Borgholio]

Even in my Prius with it's weak regen braking, going off cruise is not a big deal. I just put my foot on the pedal enough to add pressure and when I disengage cruise, I'm already costing and there's no jerkiness.

 

[JeffC]

Yeah, that is really annoying. It's a "safety" thing according to the dealer we got it from. But it's SO much better in "B" mode.

I just hate it when car manufacturers think they know what is best for you. It's like Nissan tries to be really apologetic for the Leaf. (Don't get me started on those little trees). Where in reality the Leaf is a better car than a lot of ICE's. It should embrace the differences in driving dynamics - not hide them. Tesla certainly got this one right.

I would disagree. Nissan and others got it exactly right, and there are many reasons why. Reasons which non-automotive engineers and non-racing drivers generally would not be aware of.

Tesla got it wrong when they put heavy regen on the throttle. It's one of several things they got wrong, but probably the most serious one. It's not stopping me for buying a Tesla or two, but worth pointing out. When I test drove a Model S, I liked it much better with Low Regen. I realize I'm probably in the minority on that, but I also realize most people are very likely ignorant about the reasons why.

Please read and learn: Why Regenerative Braking Belongs... On The Brake Pedal

Also be aware that Tesla itself is not monolithic on the issue. There are engineers inside Tesla who agree with me that regen belongs on the brake pedal, not the throttle.

P.S. I'm probably going to start a new thread on this, since it's an important topic on it's own.

 

[JeffK]

Please read and learn why: Why Regenerative Braking Belongs... On The Brake Pedal

No offense, but that's a load of crap

You let off the throttle before a turn and accelerate through the turn ... that's how you're supposed to drive. You will get no oversteer in a Tesla when you're actually driving correctly so your entire point is moot. Even the Google car automatically does this correctly.

Furthermore, those people who brake during a turn causing themselves to lose stability will still be hitting the brake during a turn instead of before the turn so whether regen is on the throttle or the brake makes no difference for crap drivers.

 

[JeffC]

No offense, but that's a load of crap

You let off the throttle before a turn and accelerate through the turn ... that's how you're supposed to drive. You will get no oversteer in a Tesla when you're actually driving correctly so your entire point is moot. Even the Google car automatically does this correctly.

Furthermore, those people who brake during a turn causing themselves to lose stability will still be hitting the brake during a turn instead of before the turn so whether regen is on the throttle or the brake makes no difference for crap drivers.

You are incorrect on several points. Please attend a racing school, then update your comments.

Also, you proved my point. Heavy regen on lifting off the throttle is equivalent to pressing the brakes, exactly what you are correctly suggesting is the wrong thing to do in a turn. So it seems you agree with the idea that heavy regen when coming off the throttle is the wrong thing to do.

 

[JeffK]

Sir you are incorrect. Please attend a racing school, then update your comments.

I'm quoting every racing school when I say you're supposed to brake before the turn and accelerate through the turn... You can find diagrams of the maneuver online if you need assistance with cornering.

You brake, balance the throttle or ease off and slowly press it, hit the apex, and accelerate...

 

[JeffC]

I'm quoting every racing school when I say you're supposed to brake before the turn and accelerate through the turn... You can find diagrams of the maneuver online if you need assistance with cornering.

You brake, balance the throttle or ease off and slowly press it, hit the apex, and accelerate...

Partially correct. For the constant radius part of the turn, the throttle should be constant. The acceleration only starts to happen as the radius is opening up beyond the apex.

However, none of that is the problem. The problem is that putting heavy regen on the throttle will cause inexperienced drivers to brake heavily (during a panic throttle lift) when they should be balancing the throttle in a turn. It's like stabbing the brakes in a turn, which as you suggest is exactly the wrong thing to do. Putting regen on the throttle makes that problem worse; it's bad ergonomics. Do you see what I'm saying?

P.S. LOL JeffK vs JeffC

 

[gregincal]

First of all, I'm not buying a race car. I couldn't care less about what is better for racing. And regen is not strong enough to be a problem with traction in normal driving.

 

[JeffC]

First of all, I'm not buying a race car. I couldn't care less about what is better for racing. And regen is not strong enough to be a problem with traction in normal driving.

The issue is that limit conditions that happen in every turn in racing can and do happen in a street car during emergencies.

Racing skills are extremely useful for surviving on the street. Basically it's education about vehicle dynamics, limit behaviors, and learning how to drive safely in all conditions.

No one should be racing on the street, but understanding what to do when a car approaches its limits in an emergency *on the street* can save lives. You can learn that from a racing school, autocrossing to some extent, etc.

 

[JeffK]

Do you see what I'm saying?

You could say the same thing of RWD for n00bs, yet RWD is still popular.

I believe in Darwinism, if inexperienced drivers are cornering too fast then survival of the fittest

 

[JeffC]

You could say the same thing of RWD for n00bs, yet RWD is still popular.

I believe in Darwinism, if inexperienced drivers are cornering too fast then survival of the fittest

I understand what you're saying, but car manufacturers can't take that position. They need to design for safety.

Also do you get my key point about heavy regen off throttle being like stabbing the brakes?

 

[JeffK]

Also do you get my point about heavy regen off throttle being like stabbing the brakes?

Of course, but why would someone let up all the way off the throttle if they aren't going to be hitting the brakes... If they just need to brake a little then they let up off the throttle a little.

 

[JeffC]

Of course, but why would someone let up all the way off the throttle if they aren't going to be hitting the brakes... If they just need to brake a little then they let up off the throttle a little.

Because non-racing-trained drivers panic in an emergency, and usually the first thing they do is lift all the way off the throttle. That will lead to oversteer. Adding heavy regen on lifting off the throttle will make it oversteer even more.

It a significant reason why most cars for average drivers are front wheel drive and understeer.

 

[JeffK]

I recommend autopilot for those folks.

 

[JeffC]

I recommend autopilot for those folks.

Yes, but it boils down to the same thing. In a panic situation, when the driver takes over from Autopilot, heavy regen could get them into worse trouble.

Fully autonomous driving, which may or may not happen, would very likely do better than typical drivers in an emergency. But Autopilot isn't fully autonomous and definitely won't handle all possible emergencies in the current versions.