Hybrid Revs Coasting Down Hill

[MakinDoForNow]

Going down a long hill, turn the L off, otherwise it will sound like na airplane taking off

It think max engine brake is 4500 rpm and will definitely get your attention. No need to turn L off the computer knows parameters

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[dochawk]

Going down a long hill, turn the L off, otherwise it will sound like na airplane taking off

But better to sound like that than for your maverick to take off . . .

 

[Mavster Mechanic]

Will,
Deceleration fuel cut off was basically implemented around 2010 on fuel injected vehicles.
Here's a little more information.

The 2005 Escape Hybrid behaves the same way.

 

[HeyBales]

Going down a long hill, turn the L off, otherwise it will sound like na airplane taking off

That actually doesn't matter.

You being in L with max regen allowed.
The system using Hill Descent Control will apply max regen if needed.
You going into the pads the whole way will use max regen.

It's going to happen no matter what - if the HVB is "full".

ETA:
My first experience with extended ICE braking was in WV and short steepish downhill.
Air braking couldn't keep the speed - pads was required.
Since into the pads causes max regen - it was right back to max ICE RPM when the brakes were punched on steeper grade - sounded terrible since radio was off and trying to see street names in the dark.

Ford could have done it differently and disengaged the regen from the traction motor, like they do in neutral, or N and L combo. Interesting choice.

 

[Mavster Mechanic]

That actually doesn't matter.

You being in L with max regen allowed.
The system using Hill Descent Control will apply max regen if needed.
You going into the pads the whole way will use max regen.

It's going to happen no matter what - if the HVB is "full".

ETA:
My first experience with extended ICE braking was in PA and long steep downhill.
Air braking couldn't keep the speed - pads was required.
Since into the pads causes max regen - it was right back to max ICE RPM when the brakes were punched on steeper grade - sounded terrible since radio was off and trying to see street names in the dark.

Ford could have done it differently and disengaged the regen from the traction motor, like they do in neutral, or N and L combo. Interesting choice.

Not sure what you mean.
Not sure how else you would do it.

You want nothing but friction brakes going down a hill? That's exactly what you'll get in the "N" position.

But that also gets you overheated brakes and warped rotors.

 

[Builder]

Even on a 9% grade, my Mav will only tach to 3500 - 3800 rpms once the hybrid battery is full from regenerative coasting. Must be some real steep grades to get the tach to 4500 after regen coasting. As mentioned, the downhill rev is by design once the hybrid battery is fully charged. My Mav, going downhill, will rev once the hybrid battery reaches 74% SOC. I will never understand the recharge algorithm for the hybrid and 12v batteries …. They make little sense to me.

 

[HeyBales]

Not sure what you mean.
Not sure how else you would do it.

You want nothing but friction brakes going down a hill? That's exactly what you'll get in the "N" position.

But that also gets you overheated brakes and warped rotors.

Yes, that's what I meant - there is ability to do it.
But automatically, without having to shift to neutral.
And some engine braking can still be done, perhaps not at a higher RPM.
Other cars going down that hill with me are surviving some how.
I'm sure because there isn't a next lower "gear" to select to help, there has to be some auto-assist in the matter.
I'm not talking 20 mile long steep decline either where brake trouble could occur - this was maybe 2 miles and not that steep - just happened to have full HVB because of the drive up.

I'm sure like the decision for normal 10% max power for EV, or when to drop to 12V float charge - they had their avg driving scenarios they engineered to. They changed the 25MY to 15% power (yes bigger motor) - so they do change their minds on some of those.

The hill:

 

[MakinDoForNow]

Yes, that's what I meant - there is ability to do it.
But automatically, without having to shift to neutral.
And some engine braking can still be done, perhaps not at a higher RPM.
Other cars going down that hill with me are surviving some how.
I'm sure because there isn't a next lower "gear" to select to help, there has to be some auto-assist in the matter.
I'm not talking 20 mile long steep decline either where brake trouble could occur - this was maybe 2 miles and not that steep - just happened to have full HVB because of the drive up.

I'm sure like the decision for normal 10% max power for EV, or when to drop to 12V float charge - they had their avg driving scenarios they engineered to. They changed the 25MY to 15% power (yes bigger motor) - so they do change their minds on some of those.

The hill:

They did a good job on the electric motors sizing them small to save materials armature to save size of permanent magnets and winding the copper with square wires (I think I read saving 15% of copper needed) and increasing rpm to increase capacity. Figured out improving design of magnets to handle the larger centrifugal force (18-20k max rpm?) of the larger diameter armature.

 

[Darryl]

I did not know that. Does the ICE actually fire up? In other words, are the spark plugs sparking and fuel being injected and burned just to slow the truck down? I hope the answer is no.

No fuel is being used. Just compression braking.

 

[jsus]

To all members with a hybrid. I have a 2023 with just over 13,000 miles on it. While going down a hill in normal or eco mode my truck revs like I am in a low gear. If I had a tachometer it would be showing very high rpms. I let my truck warm up then drove about 9 miles down the road. When I went down the hill my engine was definetly coasting with the rpms pretty high. It happens on a hill I go down by my house. It sounds like the truck refuses to shift into a higher gear. I know it does not have gears but near the bottom it will just stop that high rpm sound. Feels like it just shifts to a higher gear.
Has anyone else with a hybrid experienced this? Thank you and I will wait for some answers. Should I be concerned? Is this normal? My experience with my 5 speed Focus when shifting to a lower gear creates a high rpm. So does a automatic when pulling it into 2 or L creates this reving high rpm also. These scenerios are expected because I put it in a lower gear. My hybrid does it just by coasting down hill. I even pushed the throttle a bit and it still was reving like a low gear.

See: https://www.mavericktruckclub.com/forum/search/6386752/?q="grade+assist"&o=date

 

[Mavster Mechanic]

I miss the grade assist light/icon.

Some stupid update took it away.

Probably because too many people asked "what does this light mean?" on MTC.

 

[Ecorydr]

Late to this topic - just joined the forum - still waiting on my '26 Mav delivery...

Has anybody considered the CVT? Our Kawasaki 4 whlrs that have CVTs rev the motor high due to the lack of clutch release when going down hills after having the drive line energized by the motor prior, and also selecting neutral. The only way we could disengage high idle (even in neutral) was to slow down enough for the tranny auto clutch to disengage and thus enter free spin. Similar to how 4x4 axle auto hubs work when a vehicle taken out of 4x4 mode into 2wd while moving, hubs still locked in until vehicle stoped, driveline power released, and in some cases vehicle needing placed in reverse while tapping brakes several times to fully disengage.

Wonder if this is the same issue...?

 

[HeyBales]

Late to this topic - just joined the forum - still waiting on my '26 Mav delivery...

Has anybody considered the CVT? Our Kawasaki 4 whlrs that have CVTs rev the motor high due to the lack of clutch release when going down hills after having the drive line energized by the motor prior, and also selecting neutral. The only way we could disengage high idle (even in neutral) was to slow down enough for the tranny auto clutch to disengage and thus enter free spin. Similar to how 4x4 axle auto hubs work when a vehicle taken out of 4x4 mode into 2wd while moving, hubs still locked in until vehicle stoped, driveline power released, and in some cases vehicle needing placed in reverse while tapping brakes several times to fully disengage.

Wonder if this is the same issue...?

These 2 pages of posts answer your question - good info to know. And not that long of a read.
It is the eCVT in a sense but for other reasons - but not the clutch and other things you mention.

 

[dochawk]

- but not the clutch and other things you mention.

speaking of which, has anyone found the damned clutch on this things?

I mena, it's nice and all that the little spinny thing lets you go forward (but why is it D, and not F?), but it would sure e nice to shift into second . . .

 

[Mavster Mechanic]

Because if it said "F" everyone and their uncle would be asking why they put an "F" there and would be suggesting they label it "D" like every other car.

"L" is for braking. Slowing. It does nothing for you when going. Back in the original hybrids they appropriately labeled it "B". And people hated it. Got confused by it. So makers switched back to "L" for a simulated low gear. But it's a simulation. To provide braking aid.

The hybrid has no shifting. Period.
The little round thing is just a video game controller. A signal wire.

People dissed the OceanGate sub maker for having a Nintendo style video game controller to run the submarine. Your Maverick is about the same.

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