Wild MPG variation in hybrid HIGHWAY mpg: Driving style. Ambient temp, both.

[Darryl]

2025 hybrid drive from RI to Utah to pick up Oru camper from MTF member. 28mpg. cruise set to 85. Enkei 17x7.5 wheels with Toyo Open Country A/T IIIs.

Not bad given the speed you were driving. The maverick is virtually a rolling brick wall at that speed. What was the temperature?

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[Mavster Mechanic]

Just fyi the Atkinson engine takes about a 20% efficiency hit from summer high temps to 30*.

36-37 mpg highway going 70 in the summer (even with AC on) will be 29-30 mpg in the winter at highway speeds.

I drive the same 400 mile loop year round and set cruise control to 70, fuel up just prior and directly afterwards, so have a really good read on expected mpg.

I have a long (many miles) downhill coast I do routinely all in EV. Usually I pop it in N and just let gravity do it's thing.

45 MPH zone at the top.
35 MPH zone at the bottom.
Slope by chance maintains the perfect speeds. In summer.

At 85 to 90°F gravity alone maintains the speed limits with 40 psi in the tires.

At 45 to 50°F it doesn't.
I'm 4 to 5 mph under the speed limits.
And yes I added air so I have 40 psi at 45°F also.

There is something to this air density thing. It's obvious at just 45 MPH. Gotta be much worse at 75 MPH.

 

[kidshelleen]

32-ish. I had the cabin temp at 64 it so.

 

[Top Mav]

I have a long (many miles) downhill coast I do routinely all in EV. Usually I pop it in N and just let gravity do it's thing.

Does that charge the battery in Neutral? You might try putting it in slippery mode instead for a reduced-resistance charging.

 

[MakinDoForNow]

Does that charge the battery in Neutral? You might try putting it in slippery mode instead for a reduced-resistance charging.

It has zero recharge unless you lightly touch the brake pedal UNLESS your HVB is at the point (72%SOC?) the computer wants to engine brake which won't happen in neutral but would in any mode that has regen.... Coasting in N is a good way to observe how much regen is going on in any regen mode.
ETA: It has been discussed that coastin in neutral be done with the L button pushed on (carwash neutral) to keep the transaxle fluid pump running. Perhaps someone with a scan gage 2 or 3 could verify coasting temps of fluid.???

 

[Mavster Mechanic]

Does that charge the battery in Neutral? You might try putting it in slippery mode instead for a reduced-resistance charging.

Zero charge in N position.
Zero resistance (well, low as possible) in N position.

Which provides maximum coast distance in N which is my goal. Don't want charging in this situation because it would drop me below speed limits. It's only about a 3% slope.

Any brake pedal push in N will be 100% friction brakes.

Pro Tip: brake in N if you want to dry out your wet brakes and/or if you want to polish rust off the rotors.

 

[Mavster Mechanic]

It has zero recharge unless you lightly touch the brake pedal UNLESS your HVB is at the point (72%SOC?) the computer wants to engine brake which won't happen in neutral but would in any mode that has regen.... Coasting in N is a good way to observe how much regen is going on in any regen mode.
ETA: It has been discussed that coastin in neutral be done with the L button pushed on (carwash neutral) to keep the transaxle fluid pump running. Perhaps someone with a scan gage 2 or 3 could verify coasting temps of fluid.???

This post is confusing.
There is ZERO regen in N.
Always.

I have never found an exception to this.

Gear selector and mode selector are two different things and one does not rely on the other.

Consider rewording what you wanted to say.

 

[kidshelleen]

I've also been annoyed at having to refuel every 300-ish miles (out west there can be unnerving distances between gas stations). I do lust after an extended range tank option. 30gal would be nice...

 

[MakinDoForNow]

This post is confusing.
There is ZERO regen in N.
Always.

I have never found an exception to this.

Gear selector and mode selector are two different things and one does not rely on the other.

Consider rewording what you wanted to say.

Yes there is zero coasting Regen in N, however when braking in N shows regen needle in the green. I did not word it like I intended.

 

[HeyBales]

It has zero recharge unless you lightly touch the brake pedal UNLESS your HVB is at the point (72%SOC?) the computer wants to engine brake which won't happen in neutral but would in any mode that has regen.... Coasting in N is a good way to observe how much regen is going on in any regen mode.
ETA: It has been discussed that coastin in neutral be done with the L button pushed on (carwash neutral) to keep the transaxle fluid pump running. Perhaps someone with a scan gage 2 or 3 could verify coasting temps of fluid.???

I confirmed that despite the power meter going into Regen green when the brake is pressed - there is NO actual amps going to the HVB in Neutral mode.
Sat there supplying about 3A with everything on.
As soon as I turned to D - 100A charge rate.

I added the transmission fluid temp PID a few days ago (curious about temp when I hear/feel the shake & rattle on cold start neutral) - I would need one long downhill to see a difference in temps.
It is so slow to warm up, and doesn't get that warm, anyway.
DCDC Conv was warmer and faster to get there.
HVB faster than that understandably.

I think I'd have to find a PID on the tranny pump specifically to know. But I got a correct hill just around the corner to test on when I do.

 

[Cherokee]

Very interesting thread.
You guys sound like Air Force test pilots I’ve been around.
I crank up Pink Floyd, Mash the gas and get it in cruise control.
Ecoboost simplicity and mpg is fine with me.
I suspect I’ll be in a nursing before the gasoline runs out.
It’s a bitch knowing you’ll live well past 130.
:’P

 

[MakinDoForNow]

I confirmed that despite the power meter going into Regen green when the brake is pressed - there is NO actual amps going to the HVB in Neutral mode.
Sat there supplying about 3A with everything on.
As soon as I turned to D - 100A charge rate.

I added the transmission fluid temp PID a few days ago (curious about temp when I hear/feel the shake & rattle on cold start neutral) - I would need one long downhill to see a difference in temps.
It is so slow to warm up, and doesn't get that warm, anyway.
DCDC Conv was warmer and faster to get there.
HVB faster than that understandably.

I think I'd have to find a PID on the tranny pump specifically to know. But I got a correct hill just around the corner to test on when I do.

Is it possible to verify that coasting in any mode with L button pushed is 100% regen going on without any hydraulic assist? i guess the question is when power needle is in max green "Where is all the current going?". Maybe it's more of a ratio meter of power division between the planets? Is it possible that fuel control is used to engine brake partially while in low? Should be easy to check this using the hvb charge???

 

[Mavster Mechanic]

Yes there is zero coasting Regen in N, however when braking in N shows regen needle in the green. I did not word it like I intended.

The needle is an A.I. representation of what is going on.

80-90% of the time it is correct.
Sometimes it isn't.
It is run by a computer. It is a motorized device connected to a digital output. It is not actually measuring anything.

It shows level of engine brake for example during times the battery is 100% charged.

Same for speedo. Same for fuel needle. Same for temperature needle.
They are needles but are digital not analog. They move to a position they are told.

 

[HeyBales]

Is it possible to verify that coasting in any mode with L button pushed is 100% regen going on without any hydraulic assist? i guess the question is when power needle is in max green "Where is all the current going?". Maybe it's more of a ratio meter of power division between the planets? Is it possible that fuel control is used to engine brake partially while in low? Should be easy to check this using the hvb charge???

No brake pressure applied with Low mode, tested that in the past. It seems to take over whatever Mode you've actually selected, as brake and Go seem totally remapped. Haven't tested in Sport/Tow modes that keep the ICE going.
No brake pressure with brake pedal either as long as in Regen area - until slowing down below 8 mph. (which isn't done in Low mode - you'll just keep creeping as long as terrain allows)

No fuel given to ICE when spun up for wasting electric. Generator Motor does the RPM for gearing for how much is needed.
Wow I never experienced what that could be until trip to NY, and some PA hills at city speeds - holy cow 4000 RPM constantly got old. And the Hill Assist starts losing it IIRC around 5000, with speed just being allowed to increase, so you have to brake more past regen and grab some pads. But still the noise. Now I know why it freaks some people out when experienced.
I've noticed on a local downhill segment in Low - the Hill Assist keeping the speed, increased the regen beyond what Low was doing on it's own.

The max regen that Low will hit backs off as speed slows, so the amount of amps is less - gives a little room for extra braking like when I come off the highway.

I attempted a pic using Low for max regen, may not have captured the exact moment, as still a little room for more. ICE had just turned off and spinning down still. Not terrible fast 20 mph so Low wasn't max regen anymore, adding brakes for attempted max and not slipping over the line.

Since HVB only at 53% SOC - plenty of room so all power going to it - 116 A.

 

[Darryl]

Very interesting thread.
You guys sound like Air Force test pilots I’ve been around.
I crank up Pink Floyd, Mash the gas and get it in cruise control.
Ecoboost simplicity and mpg is fine with me.
I suspect I’ll be in a nursing before the gasoline runs out.
It’s a bitch knowing you’ll live well past 130.
:’P

In spite of being the author of this thread that has led to some very interesting discussions, at times I'm almost tempted to tell people "just drive the thing . It ain't that serious. But I don't because I enjoy reading the back and forth as well

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