eladts
Member
I think HOLD and ROLL come more naturally to those who are used to driving manual transmission.
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"Hold" mode regeneration in new SW
- Thread starter Sophias_dad
- Start date
I think HOLD and ROLL come more naturally to those who are used to driving manual transmission.
I used to drive manual but ...
I think HOLD and ROLL come more naturally to those who golf.
Drove with Hold yesterday and noted a few interesting things:
1. With the Car charged to 80% at the outset, Regen Breaking is Very Strong throughout the drive. I chose an uphill/steep downhill path for 20 miles and ended up at 78% charge when I finished the drive. That route would normally take me to 75%. The vacillation between 78 and 77 was interesting to watch throughout the drive. By the way, this was with the heat set at 78 and both front and back defrosters on.
2. I tried something very scary and can confirm that Auto Brake works on both uphill and down hill stops. The uphill stop was unintentional as I approached another car stopped at the yellow light. The hill is a 15% grade. The car came to a stop and I could hear the faint "click" sound when the brake engages as I took my foot off the pedal. My heart rate increased when another car pulled up behind me. But everything worked well and I was able to accelerate without problems. Two days prior I went down a 10% grade hill and was astonished that the car slowed to "0" again (I do notice a faint clicking sound when this is engaged).
My driving style has changed slightly with my ability to predict when the car will come to "0" without the need for the brake to be used. Overall, nice update. The decrease in battery range use was also a very nice benefit. I suspect that in Spring when I won't need the heater or air conditioner on, the battery range will be even better. I am also hoping to place ceramic window tints to decrease the use of the air conditioner.
1. With the Car charged to 80% at the outset, Regen Breaking is Very Strong throughout the drive. I chose an uphill/steep downhill path for 20 miles and ended up at 78% charge when I finished the drive. That route would normally take me to 75%. The vacillation between 78 and 77 was interesting to watch throughout the drive. By the way, this was with the heat set at 78 and both front and back defrosters on.
2. I tried something very scary and can confirm that Auto Brake works on both uphill and down hill stops. The uphill stop was unintentional as I approached another car stopped at the yellow light. The hill is a 15% grade. The car came to a stop and I could hear the faint "click" sound when the brake engages as I took my foot off the pedal. My heart rate increased when another car pulled up behind me. But everything worked well and I was able to accelerate without problems. Two days prior I went down a 10% grade hill and was astonished that the car slowed to "0" again (I do notice a faint clicking sound when this is engaged).
My driving style has changed slightly with my ability to predict when the car will come to "0" without the need for the brake to be used. Overall, nice update. The decrease in battery range use was also a very nice benefit. I suspect that in Spring when I won't need the heater or air conditioner on, the battery range will be even better. I am also hoping to place ceramic window tints to decrease the use of the air conditioner.
At least for now, I've gone back to 'roll' mode.
There were two reasons, which are actually one reason with two symptoms...
Apparently, 'hold' mode slows the car the last few mph not by applying brakes or even regen, but rather by applying motor power in the reverse direction(opposite current travel)...... While its doubtless a small amount of power, its still power being 'wasted' for the sole purpose of allowing me to be lazy-footed.
The second aspect of this might be a bit more serious. What happens when I'm slowing, in 'hold' mode, and one of the two wheels on an axle finds an unexpectedly slippery spot? It is almost guaranteed that it will be allowed to spin 'freely' in the opposite travel direction, and the OTHER wheel on the same axle will be free to turn in the same direction the car is going(meaning I've now lost 100% of the braking on that axle)... hopefully the traction control will hop right in and brake the spinning wheel, and that will make the wheel with traction try to slow the car.... if there's still time....the problem gets much worse if both tires on one side of the car get no traction, and now you might have no 'braking' on any of the four wheels. I wonder if the California Tesla folks were thinking that there's never weather worse than rain...
There were two reasons, which are actually one reason with two symptoms...
Apparently, 'hold' mode slows the car the last few mph not by applying brakes or even regen, but rather by applying motor power in the reverse direction(opposite current travel)...... While its doubtless a small amount of power, its still power being 'wasted' for the sole purpose of allowing me to be lazy-footed.
The second aspect of this might be a bit more serious. What happens when I'm slowing, in 'hold' mode, and one of the two wheels on an axle finds an unexpectedly slippery spot? It is almost guaranteed that it will be allowed to spin 'freely' in the opposite travel direction, and the OTHER wheel on the same axle will be free to turn in the same direction the car is going(meaning I've now lost 100% of the braking on that axle)... hopefully the traction control will hop right in and brake the spinning wheel, and that will make the wheel with traction try to slow the car.... if there's still time....the problem gets much worse if both tires on one side of the car get no traction, and now you might have no 'braking' on any of the four wheels. I wonder if the California Tesla folks were thinking that there's never weather worse than rain...
Hold mode is the single best update we have experienced in our SR+ with 19” sport wheels. Some reasons I think so:
1. Efficiency and range is improved and we will do more comparisons for exact numbers at various temperatures in the future. Anecdotally I notice more often we are below 150 kWh/km in city driving than before.
2. Single pedal driving becomes easier than going back and forth to brake all the time.
3. Reversing into a spot on an incline is much easier because now I don’t have to worry about sliding forward.
4. Brake wear is almost completely eliminated.
Love it!!
Rocky Mountain Tesla
1. Efficiency and range is improved and we will do more comparisons for exact numbers at various temperatures in the future. Anecdotally I notice more often we are below 150 kWh/km in city driving than before.
2. Single pedal driving becomes easier than going back and forth to brake all the time.
3. Reversing into a spot on an incline is much easier because now I don’t have to worry about sliding forward.
4. Brake wear is almost completely eliminated.
Love it!!
Rocky Mountain Tesla
Brisket5652
Member
DeanP
Member
Opening the door while stopped and in Hold mode will automatically put you in Park too. No need to press any buttons except the one to undo you seat belt and to open the door. So simple even a caveman can do it. 
Hold mode will only apply motor power in the reverse direction if you are on a decline where gravity is greater than the regen programming. References: One pedal mode uses the brakes? post #23, and Hold mode regen plot.
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This is a tip? Pressing the park button puts it in park below 5 MPH regardless of creep/roll/hold setting. It’s also not a very smooth way to stop the vehicle, as the car stops rather abruptly.
Even though "Hold" mode was forced on me via the update (Tesla, seriously, don't force new features that change driving behaviour on your customers' vehicles, what the hell are you thinking?), I like it. I like using brakes less. The only thing I don't like it for is backing into my slightly sloped garage, in which I found "Roll" a bit nicer. "Creep" is too jittery for me in this case.
Odd thing though, on my very slightly downhill sloped icy driveway when stopping with "Hold" mode (no brake input), I get a lot of noise from the tires just before they stop. Perhaps this is locking up. Perhaps it is momentarily spinning the opposite direction as mentioned elsewhere. Not ideal and will probably go back to Roll because of this.
I didn't use to think so, but a couple days of pure ice roads has shown me that Tesla does absolutely nothing to regain traction if regen force is the cause of loss of traction. You do get less regen, but that's because you have less traction and therefore power going to the motor/generator. Regen is bad times on ice, would not recommend. Braking at least gives you feedback via ABS if nothing else, which regen cannot do. Tesla couldn't introduce a brake pedal that also modulated regen power without a hardware change (currently it is physically connected to the brakes, as you would want it to be). Would be interesting though.
Additionally, with Roll mode, it tends to lock up (or reverse spin?) the tires coming to a stop for the very last little bit of travel. There's nothing super wrong with this that I've noticed yet, but it might be problematic on a banked surface. Would be very unexpectedly sliding sideways.
This might explain the larger than expected amount of noise on my icy driveway when rolling to a stop on it with the new "Hold" mode. It does sound like more than just the tires locking, but it's fairly brief. Currently just me and the dog at home and he can't check what's actually happening to tell me.
Uhh, sure, I guess if you want to stop by locking up the back wheels. I wouldn't recommend it but it technically does work for both stopping and tossing around passengers and cargo.
Odd thing though, on my very slightly downhill sloped icy driveway when stopping with "Hold" mode (no brake input), I get a lot of noise from the tires just before they stop. Perhaps this is locking up. Perhaps it is momentarily spinning the opposite direction as mentioned elsewhere. Not ideal and will probably go back to Roll because of this.
I didn't use to think so, but a couple days of pure ice roads has shown me that Tesla does absolutely nothing to regain traction if regen force is the cause of loss of traction. You do get less regen, but that's because you have less traction and therefore power going to the motor/generator. Regen is bad times on ice, would not recommend. Braking at least gives you feedback via ABS if nothing else, which regen cannot do. Tesla couldn't introduce a brake pedal that also modulated regen power without a hardware change (currently it is physically connected to the brakes, as you would want it to be). Would be interesting though.
Additionally, with Roll mode, it tends to lock up (or reverse spin?) the tires coming to a stop for the very last little bit of travel. There's nothing super wrong with this that I've noticed yet, but it might be problematic on a banked surface. Would be very unexpectedly sliding sideways.
This might explain the larger than expected amount of noise on my icy driveway when rolling to a stop on it with the new "Hold" mode. It does sound like more than just the tires locking, but it's fairly brief. Currently just me and the dog at home and he can't check what's actually happening to tell me.
Uhh, sure, I guess if you want to stop by locking up the back wheels. I wouldn't recommend it but it technically does work for both stopping and tossing around passengers and cargo.
Yeah, this is exactly the same as cranking the hand brake in a manual transmission car to stop it under 5mph. Sure it works and saves you some minuscule effort and time, but why?
Video: Dropbox - Video Nov 14, 6 11 59 PM.mov - Simplify your life
A Tesla "lead technician" says it's normal.
Very annoying... and very poor choice of components if that is in fact a normal sound for the iBooster.
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blee321
Member
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