My terrible morning with the Clarity

[Landshark]

I'm very curious how you calculated these figures. You using a drag coefficient calculator?

They’re taken from a Caterpillar report on motorhome fuel economy. The document included data for a 4250lb automobile. Below are a couple of screenshots from the document.

 

[Geor99]

Here is some similar behavior and some interesting back and forth on this other Clarity forum on this exact topic:

EV Battery Completely Depleted

 

[Geor99]

Here is some similar behavior and some interesting back and forth on this other Clarity forum on this exact topic:

EV Battery Completely Depleted

Here is a great video about the Clarity engine and how it works from that other Clarity forum:
The Clarity PHEV does not contain a CVT.

Honda Corporation used marketing doublespeak, in its naming of its "e-CVT" transaxle. This system is used in several Honda product lines, in addition to the Clarity PHEV.

If you'd like to see what's "under the hood", you can do no better that Professor Kelly's videos from Weber State University's automotive tech program:

 

[insightman]

I'm not a fan of the droning engine sounds in CVT-equipped vehicles (like my 2010 Insight) and was happy to learn in 2016 the upcoming Clarity wouldn't have one. To my disappointment, when the Clarity's engine is running, it sounds like it's hooked to an actual CVT. Because it sounds and acts like an actual CVT, the e-CVT moniker is quite appropriate. Other than the sound in HV, I find driving the Clarity enjoyable, but it's much more enjoyable when the engine is off.

 

[Geor99]

I'm not a fan of the droning engine sounds in CVT-equipped vehicles (like my 2010 Insight) and was happy to learn in 2016 the upcoming Clarity wouldn't have one. To my disappointment, when the Clarity's engine is running, it sounds like it's hooked to an actual CVT. Because it sounds and acts like an actual CVT, the e-CVT moniker is quite appropriate. Other than the sound in HV, I find driving the Clarity enjoyable, but it's much more enjoyable when the engine is off.

I agree with you. I have read about how the engine works; but watching that video really drove home to me how everything works. If you have interest in motors or in the Clarity motor in particular, I STRONGLY recommend taking the 20 minutes or so to watch that video.

He does a really good job of explaining everything as he assembles the gears, the 135 kw electric motor, power generator (106kw), flywheel, and drive shafts very clearly in the video. He even shows how the parking brake engages with one of the gears preventing it from rotating which prevents the car from moving.

I was surprised to see 2 oil pumps. Man, those look like a bear to replace; so hopefully that wont be needed I also learned how the oil is in use all of the time, even in ev mode; and how the gas engine only mode kicks in when the oil pressure is high. (It is possible that I am confusing oil with transmission fluid here.) He said that it only kicks in when the speed is above 62mph, the non-battery powered mode which the professor calls "Engine- Only" mode. This is different than using the gas engine to power the generator to charge the battery to propel the car via the electric motor.

He said that there are 3 modes:
EV Mode- batteries powering the 135 kw electric motor,
Series Hybrid Mode- Gas engine charging the battery via the 106kw generator to power the 135 kw electric motor, which makes it a Series Hybrid, remember that the gas engine does not power the car directly in this mode;
and
Engine-Only Mode-Above 62 mph where the gas engine turns the gears directly to power the car, which can be in use in tandem with the other modes. He said that at speeds above 62 mph, the gas engine is more efficient than the electric one.

I am sure that I will be corrected, if I misunderstood any of this

 

[insightman]

and above 62 mph where the gas engine turns the gears directly to power the car

I believe the Clarity PHEV's Engine Drive Mode can kick in as slow as 45 mph. It must be quite efficient or Honda wouldn't have added the expensive and weighty clutch, gears, and housing (along with expensive, but unweighty software) to make it possible. The Chevy Volt plug-in hybrid had a similar mode, but, unlike Honda, GM tried to downplay its existence.

 

[Robert_Alabama]

I believe the Clarity PHEV's Engine Drive Mode can kick in as slow as 45 mph.

If I did the math right based on the numbers quoted in the video (2.757 overall ratio for gasoline engine RPM to tires RPM and with 235/45/18 tires being 766 rev/mile), I get the following for the Engine Drive Mode:

Engine RPM Speed
1600 RPM - 45.46 mph
2000 RPM - 56.82 mph
2400 RPM - 68.19 mph
2800 RPM - 79.55 mph
3000 RPM - 85.23 mph

Most engines hit their optimum fuel efficiency at about 2000 rpm. The Clarity has excellent fuel economy between 55 and 60 mph. I know some of that is that wind resistance increases with the square of speed, but this also seems to be the sweet spot designed for the engine efficiency.

And please excuse me if this has been covered before... I am old with too short a memory...

 

[Conelite]

He said that there are 3 modes:
EV Mode- batteries powering the 135 kw electric motor,
Series Hybrid Mode- Gas engine charging the battery via the 106kw generator to power the 135 kw electric motor, which makes it a Series Hybrid, remember that the gas engine does not power the car directly in this mode;
and
Engine-Only Mode-Above 62 mph where the gas engine turns the gears directly to power the car, which can be in use in tandem with the other modes. He said that at speeds above 62 mph, the gas engine is more efficient than the electric one.

I am sure that I will be corrected, if I misunderstood any of this

Little clarification.

EV Mode: Drive tires are driven by the High Voltage Traction battery and Electric motor ONLY

HV Mode: The Traction battery drives the electric motor, and the ICE engine supplements extra energy to maintain the SOC of the Traction battery when HV mode was turned on. Only when speeds are above say, 60mph and steady speed, does the ICE engine engage the clutch and directly connects to the wheels.

There is NO engine only mode. Even when the engine is connected to the drive wheels, some of the power is still coming from the traction battery. It switches from 100% ICE power and Battery power. It's never steady. (I could be wrong and don't mind being corrected).

A good exercise is to go to the Power screen and see how power is delivered to and from the traction battery, and how quickly the ICE uncouples from the wheels when you give it just a little gas to accelerate at speed.

 

[Geor99]

I have seen the car run purely from the engine and not drawing any battery whatsoever, according to the monitor in the car. It is rare, but I have definitely seen it. Also, little gears appear on the screen that you can see through the steering wheel when this happens.

Once again, this is rare but I have seen it run in engine only mode on occasions.

Page 132 in owners manual shows this:

Here is a zoomed in image showing the turning gears that only appear when the motor directly powers the car. It appears in 2 of the 6 images above- middle bottom row and far right on top row.

 

[Conelite]

You are right. Good catch. I have seen that but only for very brief moments.

I guess what I meant is, you can't set it to an Engine only "Mode". It toggles back and forth from charge, regen, and sometimes runs engine only then sometimes engine+charge (Driect drive) at the same time. I see that a lot.