strider
Active Member
Thanks for posting! So that implies that traction was the reason for the 60kW limitation in the RWD Model S's and since D's have more drive wheels they have higher regen.No, P85Ds have stronger regen, around 80kW:
You can install our site as a web app on your iOS device by utilizing the Add to Home Screen feature in Safari. Please see this thread for more details on this.
Note: This feature may not be available in some browsers.
Thanks for posting! So that implies that traction was the reason for the 60kW limitation in the RWD Model S's and since D's have more drive wheels they have higher regen.No, P85Ds have stronger regen, around 80kW:
Well, we know that in later firmware Tesla has been adding some delay and phase in to full regen to not pitch people forward in their seats. So it's very possible that initial regen is lower (at 80mph in the video's case) as the car is building up to full regen for passenger comfort (at 70mph on the video's case). But you are correct in that regen is currently limited by a maximum rate assigned by Tesla. So the more weight in the car the lower the rate of deceleration. This is also something to think about for the Leaf and i-Miev drivers up-thread. The Model S is HEAVY and so even though it can provide a higher rate of regen it may take a longer distance to slow down using regen than a lighter car.I played with some numbers and they "don't add up".
Gauging from the rate of deceleration in above video it looks like regen at 70 is stronger than regen at 80.
I'd say maximum regen power in P85D is not limited by physics of the car but safety i.e. deceleration rate.
I'd like to see another video of a P85D filled with 7 people slowing down from 85 down to 60.
I think the regen power will be higher and deceleration rate will be about the same.
If regen was "physics limited", then a full car will slow down slower than an "empty" one.
Well, we know that in later firmware Tesla has been adding some delay and phase in to full regen to not pitch people forward in their seats. So it's very possible that initial regen is lower (at 80mph in the video's case) as the car is building up to full regen for passenger comfort (at 70mph on the video's case). But you are correct in that regen is currently limited by a maximum rate assigned by Tesla. So the more weight in the car the lower the rate of deceleration. This is also something to think about for the Leaf and i-Miev drivers up-thread. The Model S is HEAVY and so even though it can provide a higher rate of regen it may take a longer distance to slow down using regen than a lighter car.
Do any P85D owners have some REST telemetry for such higher regen cases? I'd like to see the numbers that the logging captures.No, P85Ds have stronger regen, around 80kW:
One thing that seems to be lost in this discussion is what would be the effect to the existing braking system with increased regen? Currently, in the winter rain/snow do hell on my rotors. I have to make a point of using the real brakes every time I drive to keep them functional. When they get too corroded they don't work effectively. Unlike a ICE car where you use your brakes all the time, the model S brakes rarely get hot during normal driving. So the rotors don't bake off the moisture like they do on a ICE car. This probem has been the biggest disappointment with the Model S brakes. I would have preffered that Tesla used speacial corrosion resistant alloys in the rotors to prevent this issue.
Interesting -- that's the first time I've seen it noted that Tesla has a fix for this other than "use your brakes every so often to scrub off the rust". Is this a widely-known thing, and are they delivering current cars with corrosion-resistant brake parts?We had this same problem. I told the service center and they applied the fix. We have never had a problem since. Even after coming out of a car wash, which was the most dangerous IMO. They changed the pads and installed dust shields. Problem 100% gone!
So can anyone with a P85D confirm that using the brake pedal results in regen? i.e set the regen setting low so that when you lift of the throttle you don't get full regen. Now apply a little bit of brake. Does the regen rate go up?
Somewhere up the thread I expressed some concerns about "Single Pedal Driving" vs. transitioning in-out of other vehicles. OK, I was wrong. I've had the Model S for about a week, and I LOVE SPD. And transitioning is no problem (other than I miss my Tesla when I drive anything else).
Also meaning that it can decell down to zero (in most circumstances?) making electricity and not having to make any brake dust?+1
But reports have it that BMW does it even better with the i3: apparently it will decelerate all the way to zero without using the left pedal.
No. Under some low speed it stops "making electricity" starts using energy to slow down even more (forcing motor to run bacwards while it is still running forward).Also meaning that it can decell down to zero (in most circumstances?) making electricity and not having to make any brake dust?
So it sacrifices range for saving on brake dust? And promotes rust buildup on the rotors? When you put it that way, it doesn't sound very exciting, does it?No. Under some low speed it stops "making electricity" starts using energy to slow down even more (forcing motor to run bacwards while it is still running forward).
I think everyone who has an interest in this thread (and the head of Tesla engineering) should have a go in an i-MiEV - or at least the Peugeot/Citroen badged ones (I have the Peugeot). The implementation of the regen on this car is, IMO, simply perfect. It is quite possible with the use of good forward vision and a reasonably light right foot, to drive entirely on the accelerate except for the very last few feet (esp if you are stopping on an incline). The function of acceleration and deceleration by accelerator pedal only is flawless and totally smooth. I am looking forward to seeing how the MS compares but from what I have read here it looks like I will be missing my iOn for this aspect of its amazing engineering accomplishment, at least.
Yes, the i3 will regen all the way to 0, and then hold at 0 (the car will not move backwards even on a steep hill).Also meaning that it can decell down to zero (in most circumstances?) making electricity and not having to make any brake dust?
As far as I can tell, the i3 will apply friction brakes if it cannot use regen (with a 100% charged cold battery for example). I determine this empirically from the noise it makes (rusty disused rotors make a different sound than regen), as I cannot feel any difference, but I can hear one.No. Under some low speed it stops "making electricity" starts using energy to slow down even more (forcing motor to run bacwards while it is still running forward).
When one fully lets off the accelerator of the i3 at highway speed, it's regen feels like down shifting into 2nd gear, occupants and loose gear are thrown forward and the car comes quickly to a full stop. In the Tesla, the feeling is more like shifting into 3rd gear. Because the mass of the cars is so different it's hard to compare, and because the i3's regen continues with a slight lessening as it slows down until the car stops completely, unlike the Tesla's gentle roll off of regen to a coast at about 10 MPH.In another post someone said that i 3 has stronger regen. I assume that is probably a stronger g force effect but because the car is much lighter still less energy captured. Does that seem right? Otherwise I'm very surprised I three has a stronger regen.