Is personal preference the main reason to use one-pedal driving (1PD)? Could stopping distance be a reason?

[RMoore]

By most accounts, the extent of regeneration appears largely independent of the choice of braking mode (or whether one chooses whisper, engaged, or unbridled, which also impacts the 1PD experience). So is the main reason for using 1PD just personal preference/preferred driving style? I was wondering if it could be safer in an emergency situation. With 1PD the car will start braking right as one releases the accelerator pedal, whereas without it there would be minimal deceleration during that period between taking your foot off the accelerator pedal and depressing brake pedal. That period seems hard to pin down, but a quick search suggests that it could range, depending on lots of factors, from a few tenths of a second up to close to a second. Are folks aware of tests comparing stopping distance with and without 1PD using the same car?

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[generaltso]

I think it’s negligible and really just boils down to personal preference.

 

[RMoore]

I think it’s negligible and really just boils down to personal preference.

You may very well be correct but it would be interesting to see some data. At 60 mph, you go 8.8 ft every 0.1 s. So if one has a very fast reaction time and can make the transition in 0.2 s, one has still traveled 17.6 ft during that time (assuming zero deceleration). A more relevant question might be at what speeds do you hit another car under different scenarios of speed traveled and 1PD vs not. I would think the major magazines that test cars would have looked into this but perhaps not.

 

[ARK]

It is mostly personal preference, though I think Edmunds did a test recently where they found 1PD to be slightly more efficient than coasting. I suppose though the same result could be achieved by getting on the brakes enough to trigger some regen without getting into friction brake territory if 1PD is disabled, or I suppose the test itself could have just been a bit imprecise as to result.

But yeah, you don’t need to use 1PD if you don’t like it (I don’t), and face no meaningful downside for skipping it on the Mach-E. I think most people who do it find it more comfortable to be able to modulate acceleration and braking, even stopping, with just the use of one pedal.

 

[JamieGeek]

By most accounts, the extent of regeneration appears largely independent of the choice of braking mode (or whether one chooses whisper, engaged, or unbridled, which also impacts the 1PD experience). So is the main reason for using 1PD just personal preference/preferred driving style? I was wondering if it could be safer in an emergency situation. With 1PD the car will start braking right as one releases the accelerator pedal, whereas without it there would be minimal deceleration during that period between taking your foot off the accelerator pedal and depressing brake pedal. That period seems hard to pin down, but a quick search suggests that it could range, depending on lots of factors, from a few tenths of a second up to close to a second. Are folks aware of tests comparing stopping distance with and without 1PD using the same car?

I think you have an invalid assumption here with respect to "an emergency situation".

In an emergency situation you are going to hit the brakes no matter what 1-P on or not. (Note that in 1-P mode you still can hit the brakes and they still work, its not an either/or situation you can always hit the brake pedal.)

1-P does not stop the car very quickly regardless of drive mode (you do have to plan your stops out and start braking earlier with 1-P on).

As far as efficiency is concerned its pretty much the same regardless of 1-P on or not: The Mach-E has a blended brake and will regen quite a bit when you press the brake pedal. The "coasting" arguments notwithstanding (people who say 1-P is worse because they think of "coasting" is removing your foot completely from the accelerator instead of finding the "coast" spot in 1-P mode).

Thus it comes down to personal preference: If you like 1-P or not.

Oh there is one situation where 1-P mode is safer: If you are driving alone and become incapacitated for some reason. In 1-P mode the car will come to a stop. (Of course if you have cruise control on it doesn't make a difference...)

 

[RMoore]

I think you have an invalid assumption here with respect to "an emergency situation".

In an emergency situation you are going to hit the brakes no matter what 1-P on or not. (Note that in 1-P mode you still can hit the brakes and they still work, its not an either/or situation you can always hit the brake pedal.)

1-P does not stop the car very quickly regardless of drive mode (you do have to plan your stops out and start braking earlier with 1-P on).

I fully agree that in an emergency one would not rely on 1PD alone and would of course hit the brakes. I was simply asking if during the time it takes to move your foot from the accelerator to the brake and fully depress the brake pedal (which takes some time, even if small), 1PD would have enabled some degree of braking that would be meaningful. It should start slowing you down--the question is how much and whether it will ultimately matter. In theory, it seems it should help at least a little; in practice, I just don't know so was curious to see if there were data out there.

There are endless debates about benefits of using two foot driving over one foot with ICE cars. Looking at stopping distance alone, using two feet (one on accelerator, one on brake) it seems to stop sooner since it cuts down the time to activate the brake. Whether one can extrapolate from that to the 1PD situation is another question though.

 

[B25Nut]

An alert non-1PD driver already has their foot off the accelerator and is ready to fully press the brake pedal instantly in an emergency braking situatioin, so I feel the reaction time advantage goes to driving with 1PD off.

 

[JCHLi]

I find there is a delay (albeit very short) from taking the foot of the accelerator and braking starting in 1PD. It's just anecdotal, but in some cases I find that I actually use the brake even in 1PD because it doesn't start to decelerate quick enough (note, in this case I'm talking about how quickly I start to decelerate, not how much deceleration there is.)

But I can see the case for some situations where as a human we might freeze and not find the brake quickly, but 1PD could start to slow you down while you are frozen.

 

[phil]

I have always thought the 1pd should be a safety advantage for stopping distance, but I agree with those who believe it's negligible.

I had an emergency situation the other day, when a Tesla blithely sailed out of a parking lot without stopping or checking for traffic. When he saw me bearing down on him, he slammed on his brakes, stopping directly in front of me. I had my brake pedal on the floor before I even realized what happened. Electric motor-braking might have helped, but the time and the deceleration are so small, I doubt it would even be worth a tenth of a second.

Still, I stopped about six inches short of that Tesla idiot, so...

 

[HuntingPudel]

I'm a dinosaur. I prefer using the brake pedal to not. Just my preference. More power to those of you who can learn a new trick (old dog here). ??

I also am a horrible left-foot braker, so I tend to have my right foot on both the throttle and the brake and my left on the clutch (on cars so equipped - double-clutch down, clutchless up). The driving coaches I've had haven't exactly given up on me, but they do roll their eyes at me. Then again, that might be because my teeth are on the steering wheel. ??

 

[Motomax]

I didn’t like like the two stage feel of the brake pedal during blended braking. In 1PD the brake pedal is very responsive with minimal input.
yes you get used to it and yes the Amount of braking is the same with either method. If you want to thread the needle, it does appear that 1PD will be a fraction faster but most likely negligible.

 

[woody]

1PD saves wear and tear on brakes.
In most EVs and hybrids regenerative braking (1PD, brakes) generates a noticeable amount of energy back to the batteries. However, the MME for reasons I am not certain, regenerates less than others ( previous hybrids, EVs, etc. over same route for comparison). Others regenerate the energy driving down the hill that was used to drive up the hill. Not the case with the MME.
Perhaps the regenerated energy feeds the 11kWh of the battery we are prohibited from using. Probably a way of determining that and some forum member may have done so (my guess).

 

[Motomax]

Others regenerate the energy driving down the hill that was used to drive up the hill.

If you mean regen the same amount going downhill as it took to go up , that would be impossible.

 

[generaltso]

1PD saves wear and tear on brakes.

But it doesn’t. Regenerative braking saves wear and tear on the brakes. But you get that with 1PD on or off.

 

[dtbaker61]

By most accounts, the extent of regeneration appears largely independent of the choice of braking mode (or whether one chooses whisper, engaged, or unbridled, which also impacts the 1PD experience). So is the main reason for using 1PD just personal preference/preferred driving style? I was wondering if it could be safer in an emergency situation. With 1PD the car will start braking right as one releases the accelerator pedal, whereas without it there would be minimal deceleration during that period between taking your foot off the accelerator pedal and depressing brake pedal. That period seems hard to pin down, but a quick search suggests that it could range, depending on lots of factors, from a few tenths of a second up to close to a second. Are folks aware of tests comparing stopping distance with and without 1PD using the same car?

main reason for 1-p is to recapture braking energy to extend range when possible, as much as possible. A little practice, and you'll find you virtually never touch the brake pedal except for the unexpected 'event'.

Braking distance might be reduced *fractionally* by the time it takes you to move your foot from accelerator to brake..... but after that braking distance would be simply a function of traction available and ABS if you stomp on the brakes.

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