downhill without downshifting?

[Scorpio3d]

Parts of this thread remind me of when I was a kid and had to walk to school uphill both ways! Now, if I can just find the inverse place to live where it is downhill both ways, I would never have to charge my truck??

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[Sedawk]

In the real world, though, we don't live by scientific rules, solely ....

Wrong. In the real world we DO live by scientific rules solely. Period. End of Story. If you are trying to win an optimal energy transfer argument by not applying the rules of basic scientific theory you are going to have a bad time.

We don't live in the quantum world (or better said, the quantum scale) - energy is conserved and easily accounted for - these rules don't change depending on the traffic in front of me. This sentence quoted above really proves my point that people assign a mysterious energy recovery to 1-pedal driving.

If there is traffic in front on me - fine. 1-pedal braking is not going to increase the overall energy efficiency if the vehicle needs to slow more than I would when I press the brake pedal. When I press the brake pedal (2-pedal driving) when slowing gently the physical brakes are not used - that energy is recovered and is stored in the battery. If you are using sport mode and 1-pedal driving then the acceleration and regenerative braking are more aggressive - but it isn't storing more energy on the whole. In fact with every energy transfer, speeding up by applying electricity to the motors or slowing down by capturing electricity generated from the motors, there is some loss. By just coasting with 2-pedal drive I am not occurring those losses with energy transfer to the battery and back.

Look at any experienced EV reviewer - they generally love the Lighting, but are very critical of the 1-pedal tuning. It is poor. You are not being more energy efficient than a 2-pedal driver that is consistently getting +95% brake coach scores. It's even worse in sport mode.

 

[Sedawk]

Parts of this thread remind me of when I was a kid and had to walk to school uphill both ways! Now, if I can just find the inverse place to live where it is downhill both ways, I would never have to charge my truck??

You just have to live on Penrose street - problem solved!

 

[hturnerfamily]

actually, just like in ANY motor vehicle, physical brakes ARE applied AT THE MOMENT you press the brake pedal, and also the BRAKE LIGHTS immediately activate. There is no 'let's wait for REGEN before we start' scenario when applying the brakes - they work WHEN you press them.

Now, that does NOT mean that you don't also capture REGEN while the braking is occurring, yes, you do.... but it does not 'wait' for the REGEN to hit some magical number before it applies them.

REGEN happens many times without braking, but ALWAYS with braking.

 

[Sedawk]

REGEN happens many times without braking, but ALWAYS with braking.

Sorry - but here is that science thing again - you can't get away from it.

If your truck is "REGEN" as you put it - it is taking energy away from its forward momentum and transferring it to the battery. It is slowing down - also known as braking. It does not happen any other way. The second you take your foot off the gas in 1-pedal mode your brake lights come on - because you are slowing down.

Also - the physical brakes DO NOT ENGAGE automatically when you press your brake pedal on your Lightning - this shows that your understanding of the process is completely wrong. The truck does a little math (I believe either 60 or 120 times per second). It looks at how much you have pressed the brake pedal. If the motors (now acting as generators) can slow the truck down enough via regeneration then physical brakes are NOT engaged. If your brake coach score is 100% then the physical brakes are only engaged right when the truck stops - NOT before (unless you press really hard and the regenerative braking system needs some immediate help).

I'm very confused on why you would engage in this argument when you don't have a clue how the regenerative braking system on the F150 Lightning works.

 

[Shawnson]

Just for fun ...
A Mechanical Engineer would conclude that the Lightning does have a transmission ... "a mechanism which transmits power from the motor to the wheels". The Munro tear-down describes "The reduction gear is a coaxial, planetary gear reduction system with a drive shaft through the center ..." So, while the "transmission" may not change gears, it does change the speed of the motor relative to the drive shaft. An Engineer would call it a single speed transmission or gearbox. And for more fun ... the 2022 Ford Lightning Technical Specifications show the motor build location as the Van Dyke Transmission Plant. ?

Never ever utter these words in front of someone we are trying to explain EVs to. We will curse you FOREVER

 

[Ishkatan]

When I traverse a steep hill, I set the adaptive cruise control and the truck brakes within a few miles of the setting. If it does not brake enough I simply lower the target speed.

 

[invertedspear]

I don't think there is any indicator on the user interface when friction brakes are being used by cruise control or 1PD.

Indirectly you can determine this though. If you have the power distribution up in MyView on the gauge cluster screen, you can see when regen maxes out. When it does, friction brakes start getting applied.

 

[hturnerfamily]

Let me give you my testing results, from tonight's drive, in various modes/1pd options, braking, and CRUISE:

A) 1pd is an additional 'Mode', on top of either the underlying NORMAL or SPORT Modes, BUT, in reality, it is a MODE ALL IT'S OWN: It is designed to bring the truck to a stop, when you come off the GO pedal.
This means that no matter the underlying mode, when 1pd is activated, IT WILL apply the MAXIMUM amount of REGEN, and will also IMMEDIATELY start braking.

: : the brake lights are the indication that 1pd IMMEDIATELY starts applying the brakes. It does NOT 'wait' until a certain point - it is immediate, as your brake lights will indicate.
: : the amount of REGEN that 1pd applies is the greatest amount of REGEN the truck can provide, no matter the speed. You will see this immediately when you come completely off the GO pedal. Whether 25mph, 45mph, or 65mph, the REGEN is the same in each case, and the braking to go with it. If you wish to 'customize' this amount of REGEN and braking, keep 'some' pressure on the GO pedal, or 'feather' the pedal, slowly, or as needed.

: : as above, the 'amount' of braking can be feathered by the amount of pressure you apply to the brake pedal. ANY amount activates the brakes, and the brake LIGHTS.
Yes, the 1pd mode 'might' apply a CONSISTENT and INCREASING amount of braking as the truck is coming to a slower speed, but the brakes are applied AT THE MOMENT 1pd is activated.
You will see this proven by your brake lights, anytime you come off the GO pedal while in 1pd mode.
You will NOT see brake lights when you come off the GO pedal when either NORMAL or SPORT mode, ALONE. No braking is activated since only REGEN is applied by these modes.

B) 1pd MODE could be a 'MODE' all it's own, but since you must choose a DRIVE MODE when you put the truck in gear, or allow the NORMAL mode to default as the Drive Mode, you have to then ADD the optional 1pd ACTIVATION to either of these modes. 1pd is NOT an option for the other modes.

C) Choosing to use 1pd mode, or not, is really only a choice of the driver.
It does NOT create a more efficient travel, overall, over the long term, because the braking that happens automatically every time you come off the GO pedal is also robbing the momentum already built up.
Applying the physical brakes while in only Normal or Sport mode aren't going to create any 'better' outcomes, either, overall, over the long term.
It's really only a personal preference.

-If you like a smooth, easy drive - use NORMAL.
Very little REGEN, but You'll need to apply braking often.
-If you like a smooth drive, but more use of the GO pedal - you SPORT.
Much greater REGEN, and You'll use the brake pedal a LOT less often.

-If you like an AUTOMATED slowing and braking almost ALWAYS - add 1pd to either of those.

-If you like a blending of SPORT and NORMAL, use TOW HAUL mode. It doesn't matter whether you are towing, or not, it's just a blend of those two modes - middle of the road REGEN.

CRUISE CONTROL:

Interestingly, when in CRUISE CONTROL, you are effectively telling the truck to manage ALL driving speed, braking, and REGEN, all on it's own.

Your DRIVE MODE does not matter while on CRUISE CONTROL. You are allowing the truck to control this.

Your 1pd choice does not matter while on CRUISE CONTROL. You are allowing the truck to decide when to REGEN(slow) or STOP, if traffic ahead dictates.

Now, if you apply the BRAKES yourself, while cruise is active, you are effectively turning OFF Cruise Control, and your underlying Drive Mode, or 1pd option, will dictate how the truck responds when you then come off the brake pedal, and until you reactive Cruise Control.

 

[hturnerfamily]

incorrect: any vehicle applies the brake lights IMMEDIATELY when the brake pedal is applied - it matters NOT whether REGEN is being applied, or not, or whether it is an EV, or not.

I wrote this testing outcome because there are many owners who incorrectly 'assume' how the truck works - the ONLY WAY to know is to test the outcomes.
=Brake lights don't alluminate 'just because' the truck is 'slowing' to a certain speed, but ONLY because the brakes are being applied, period.
=CRUISE changes the nature of how many might assume the truck works, as no 'Drive Mode' controls that, only the truck, itself, does.
=1pd also does the same, as it allows the TRUCK to control the slowing and braking, not the Drive Mode.

you might 'assume' you know how these things work, but test yourself to see. Your brake lights don't lie. If you don't physically apply them, they don't come on. If Cruise or 1pd applies them, they do. REGEN itself does NOT apply the brakes, EVER.

 

[GDN]

I don't think OP has come back to this thread, are you all sure you aren't just getting dragged along?

 

[ZeusDriver]

Wow, you really have convoluted this thread on a thousand unrelated topics. But since you ALSO have how the brake lights work wrong and are telling folks incorrect info....so here we go.

First, we apparently have to set some terms

Regen - ANYTIME energy is flowing INTO the battery from the electric motors. Regen is when kinetic (and potential) energy is turned into electrical energy. This is usually the electric motors slowing the vehicle down, although it can also be maintaining the same speed on a downhill.

Physical Brakes - When the Brake pads engage the brake rotor. Not the pedal, that is the brake pedal, when I say physical brakes I mean the calipers pushing on the pads and pressing them into the rotors.



Nobody, absolutely nobody, said the brakes lights are not illuminated when the brake pedal is touched. If you thought that then you need to go back and read what was said again.




I literally did exactly that.



Absolutely not correct. This is wrong. The EU has written into a law that the brake lights will illuminate anytime the vehicle slows at a rate greater than .13G. The US does not have that law but the Lightning is a global platform and still follows it. Consumer Reports did a test of all electric vehicles in their fleet, of which they have a lightning, and they specifically identified all vehicles that did not illuminate the brake lights when slowing, specifically when slowing using regen. The Lightning was NOT identified as failing to illuminate the brake lights when slowing on regen only.

The lightning absolutely will illuminate the brake lights even if the brake pedal is NOT pressed. The lightning WILL illuminate the brake lights if the physical brakes are NOT being used.




This is incomprehensible. No point is made here.

However, guessing at what you are trying to say, cruise control will both speed up the truck and slow it down, mode is irrelevant. When cruise is engaged the truck will use regen to slow the vehicle.
I do not have a hill big enough to determine if the truck will use the physical brakes to maintain speed when exceeding the deceleration capabilities of regen.



I HAVE tested them. Right now, immediately, describe your test setup, what components, where, how, and observed results. I HAVE plugged in a monitor and wathed the brake line pressure, I HAVE watched the truck use REGEN to slow down. I HAVE observe that pushing on the BRAKE PEDAL does NOT apply the PHYSICAL BRAKES.

Again, this HAS BEEN TESTED. Consumer reports identified which vehicles in its fleet did NOT light the brake lights.
The Lightning is a global platform and the EU REQUIRES that the brake lights illuminate when slowing at a certain rate regardless of if the brake pedal is pushed, if the physical brakes are used, or if regen is used.

You seem to be making the argument that the brake lights coming on means the physical brakes are being used. There is NOT a 1 to 1, and only 1 to 1, correlation to the brake lights and the physical brakes (pads, calipers, rotors, etc). I have PROVEN that the lightning will slow down, using the brake pedal, without engaging the physical brakes. The brake light does NOT tell if the physical brakes are being used.

And for the love of god use the quote and reply button, one folks don't know who or what exactly you are responding to, and two is damn sure seems like you are trying to slip in a comment hoping nobody notices and you can have the "last word".

This is all correct. It is remarkable how far afield people can go in inventing features and functions of systems they do not understand.

My preference is for the term "friction brakes" instead of "physical brakes", because, in two pedal driving, a physical pedal is pressed to modulate regen. That seems to confuse people. (Of course, physicists would say the regen is "physical" too, as is virtually everything you can observe and many things that you cannot, at least easily.)

 

[ZeusDriver]

BTW, the screen on Teslas shows a little picture of your car as if seen from above. The brake lights in that little car go on and off as the real brake lights do. Of course, the last thing you should be doing when driving is watching a stupid video screen, but if Fords had the same "feature" then half of the posts in this thread would not exist (assuming driver awareness of this screen.)

More bloviating: anyone who has done a lot of bleeding of brake systems in conventional old cars, would find the pedal feel on a lightning too mushy and springy. That first inch or two of travel is there to permit modulating regen before the friction brakes come into play (which if you drive smoothly, almost never happens.)

Even more bloviating: My old Citroen SM had a brake button on the floor that actuated a valve (instead of pushing on a piston in a master cylinder). Braking hydraulic pressure (supplied by a central hydraulic system pump) was applied to the "back" side of the button, pressing against your foot, to provide feedback. Worked perfectly. To reduce unsprung weight, the front brake discs were mounted at the differential, at the inner ends of the half shafts.

 

[davehu]

1) That's funny - it does for me.

2) The truck regenerates, IN ALL MODES, when you let up on the accelerator, and when you press on the brake pedal. On a hill, use Sport Mode, and it will brake pretty aggressively with regen.

agree, mine holds speed steady uphill or down.

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