mkhuffman
Well-Known Member
- First Name
- Mike
- Joined
- Nov 19, 2020
- Threads
- 24
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- 6,075
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- 8,021
- Location
- Virginia
- Vehicles
- 2021 MME GT, Jeep GC-L, VW Jetta
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- #1
I have seen so many posts in the forum debating, even arguing, that 1PD or 2PD is the most efficient way to drive. I have long taken the position that you can drive equally efficiently using either method, but I have never seen anyone prove it with real data. So that is what I set out to do.
First off, it is important to understand that in the MME, 1PD works exactly the same way either in Whisper, Engage or Unbridled (mine still has the “d”). So it does not matter, but all my testing was done using Whisper mode.
The main reason I use Whisper in my GT is the way Adaptive Cruise behaves: it is MUCH smoother if the car is in Whisper. And I use Adaptive Cruise a lot, like every time I drive. Switching back and forth from Unbridled to Whisper is too much of a PIA to make it worth it. I can still get 1000 Amps of acceleration just as easily in Whisper as I can in Unbridled, so I am not really missing anything.
To compare regeneration between 1PD and 2 PD I did two different tests.
Results Summary
Results Details - Test 1
The maximum regeneration I could get using 1PD was around 86 kW. The reason the chart below shows 94.76 kW is because I came up on some traffic and had to briefly use the brake pedal. Rather than redo the entire test, I just used it as is. But obviously it isn’t even close to what 2PD can produce. I am sure if I tested more, I could exceed 123.73 kW in 2PD as well. If I were to guess, maybe the limit is around 125 kW? Could it really be a nice round number like that?
Results Details - Test 2
The graphs really speak for themselves mostly. What is interesting is I was able to stop more smoothly using 1PD, as shown in the data. You can see I slowed down very gradually using 1PD, but had less of a smooth ramp in 2PD. People often think they can drive more smoothly using 2PD, but apparently, I can’t.
The regeneration graph shows I got a lot more initial regen in 2PD, but since I slowed more abruptly, I had to back off in order to reach the stoplight. But visually you can tell that the same amount of energy was returned to the battery.
Conclusion
Drive in any mode that makes you happy, but don’t pick a drive mode just because you think it is more efficient. Maybe it is easier for you to drive more efficiently in 1PD or 2PD, but it still comes down to the way you drive and not the drive mode. You can be just as efficient in 1PD as in 2PD. It is just a different way of driving.
Note: this conclusion only applies to the MME. Other car manufacturers may use brake blending differently in different modes, so I would not assume you can repeat this in every BEV. On the other hand, this is how every BEV should behave IMO. So if others do not, it is because they are inferior. Vastly inferior.
Now go out there and do some WOTs! This car is made for fun, not efficiency!
First off, it is important to understand that in the MME, 1PD works exactly the same way either in Whisper, Engage or Unbridled (mine still has the “d”). So it does not matter, but all my testing was done using Whisper mode.
The main reason I use Whisper in my GT is the way Adaptive Cruise behaves: it is MUCH smoother if the car is in Whisper. And I use Adaptive Cruise a lot, like every time I drive. Switching back and forth from Unbridled to Whisper is too much of a PIA to make it worth it. I can still get 1000 Amps of acceleration just as easily in Whisper as I can in Unbridled, so I am not really missing anything.
To compare regeneration between 1PD and 2 PD I did two different tests.
- I measured the maximum regeneration I could achieve in each mode.I did this by driving as aggressively as possible, slowing as fast as 1PD could slow without using the brake pedal. In 2PD obviously I had to use the brake pedal to slow down.
- I did the exact same stop (same distance at the exactly same place in the road) from 50 mph using each mode. I tried very hard to slow down at the same rate in both 1PD and 2PD. That meant in 1PD I had to carefully modulate the go-pedal to slow down gradually to the stoplight while never pressing the brake pedal.
Results Summary
- 2PD generates a higher level of regeneration to the battery than 1 PD does. Of course if you drive using 1PD, you can also use the brakes, which allows you to increase the regeneration before the friction brakes engage. 1PD is not set to maximum regen, obviously.
- Both 1PD and 2PD appear to generate exactly the same amount of regeneration when stopping from the same speed and for the same distance.
Results Details - Test 1
The maximum regeneration I could get using 1PD was around 86 kW. The reason the chart below shows 94.76 kW is because I came up on some traffic and had to briefly use the brake pedal. Rather than redo the entire test, I just used it as is. But obviously it isn’t even close to what 2PD can produce. I am sure if I tested more, I could exceed 123.73 kW in 2PD as well. If I were to guess, maybe the limit is around 125 kW? Could it really be a nice round number like that?
Results Details - Test 2
The graphs really speak for themselves mostly. What is interesting is I was able to stop more smoothly using 1PD, as shown in the data. You can see I slowed down very gradually using 1PD, but had less of a smooth ramp in 2PD. People often think they can drive more smoothly using 2PD, but apparently, I can’t.
The regeneration graph shows I got a lot more initial regen in 2PD, but since I slowed more abruptly, I had to back off in order to reach the stoplight. But visually you can tell that the same amount of energy was returned to the battery.
Conclusion
Drive in any mode that makes you happy, but don’t pick a drive mode just because you think it is more efficient. Maybe it is easier for you to drive more efficiently in 1PD or 2PD, but it still comes down to the way you drive and not the drive mode. You can be just as efficient in 1PD as in 2PD. It is just a different way of driving.
Note: this conclusion only applies to the MME. Other car manufacturers may use brake blending differently in different modes, so I would not assume you can repeat this in every BEV. On the other hand, this is how every BEV should behave IMO. So if others do not, it is because they are inferior. Vastly inferior.
Now go out there and do some WOTs! This car is made for fun, not efficiency!