How to Improve the Clarity

David, Good point on how your BMW worked, I had not considered it that way.

 

Hi Neal,

I de-badged my car over summer when it was relatively new so the glue on the badges was still soft. I used a flat plastic trim removal tool and worked it into one end of the badge - there's probably a youtube video of someone doing it. Be careful about using a heat gun or even a strong hair dryer as you could damage the paint or the plastic plug door. Car looks much cleaner without the awkward badges. I also took off the tail badges as they were not on straight.

Btw, I gave it the Clarity Fuel Cell look with the black roof. The dealer did the tint at delivery with 30 VLT front and 20 VLT in the back.

 

Rich,

Your car looks great! Love all those changes. Add those black faux full wheel well wraps that a previous poster posted and the look would be complete!

 

I have a very low opinion of CVT transmissions and won't buy a car with one. There are variations of course, such as the eCVT of the Synergy Drive of a Prius which is brilliant. But many rely on some sort of slipping design which I feel is inherently an unreliable design. There have been enough CVT fails for me to stay away.

I haven't experienced the speed problem. I feel Honda got it right for us.

 

I may be wrong about this, I haven't paid much attention to the gear icon. Since the engine is an Atkinson Cycle engine which is highly efficient at steady speeds but not so good at acceleration I think the clutch only engages when traveling at a constant speed. When accelerating the engine is disengaged.

 

I believe the ice comes now for heat if it is below 10 degrees?

 

My 2012 Prius Plugin's heat came off the ICE so that if I wanted to drive in EV in the winter, I had to leave the heat off and just use the seat warmer. Even with a full battery, the ICE would come on more often than my Clarity so far (I haven't had it long enough to experience how it runs in hot weather yet.)

Eventually, if I was going more than a mile or two, I would have to spring for the HV and let the ICE come on although often it would come on anyway to warm up the battery. As for noise, when on the interstate and accelerating uphill, the roar of the engine was louder than anything I have experienced with the Clarity yet.

 

2. Its annoying sometimes that there is no mode with no regenerative braking. I would like to be able to give the right paddle one pull and have it go into this mode for maximum coasting. It should also stay in this mode until you give a pull on the left paddle.

You can coast by shifting into neutral. It's fun!

 

Hi Insightman - Can you let me know where you learned about this? My understanding is different (about dropping out of Engine Drive mode when more power is demanded), but I think you've dug into this much more than me. Please let me know if you have links that can help.

When reading the SAE paper on the Clarity I believe it said that was true of the previous generation. But I could have my facts wrong.

 

I'm mystified by the algorithm that engages the direct drive (and thus turns on the gear icon). I can be on a flat stretch of highway, at the same speed, not accelerating, and sometimes I see the gear icon and sometimes I do not. You're right; as soon as I accelerate it disappears, to return in a few seconds or a few minutes. Maybe I am not seeing the slight grade but with constant speed I would expect to see the gear icon a lot more.

 

The certainty of my Clarity switching from the ephemeral Engine Drive mode to Hybrid Drive mode is based only on my experience. However, you've now given me the opportunity to blather on about my theories regarding the way this car's modes work.

When Honda initially revealed the specs for the Clarity Plug-In Hybrid claiming a maximum of 212 horsepower, I was extremely curious about where that number came from. Why wasn't the maximum horsepower the engine's 103 hp and the traction motor's 181 hp? I assumed it wasn't the total of these two numbers because the engine and motor develop their maximum horsepower at different RPMs and the highest value in the curve showing the additive values of these numbers was 212.

Then I learned that the traction motor required both the battery and the engine-driven starter motor/generator working together to provide enough power to drive the traction motor to its maximum 181 horsepower. Without help from the engine-driven starter motor/generator, the traction motor could produce only 121 horsepower on battery power alone. That fact made the Engine Drive mode even more mysterious to me.

I made a presentation poster for an EV car meet last summer. For this poster I expanded the i-MMD mode transistion chart created by Honda's engineers for their SAE paper. The change shows that the battery can both be charged and discharged in Engine Drive mode:


The most interesting item is that the starter motor/generator is not active in Engine Drive mode. In Engine Drive mode, when the traction motor is not sending power to the battery (ie. when accelerating), all of the power from the battery-powered traction motor (121 hp) and the engine (103 hp) is going to the wheels. Again, because Honda says that total is 212 hp, not 224 hp, I'm back to assuming that the power curves from these two devices do not peak at the same RPM number.

So when you stomp on the accelerator while traveling in Engine Drive mode, why does the Clarity PHEV go back to Hybrid Drive mode (the 181-hp engine+battery power configuration, not the user-selectable HV Mode)? The answer must be the very tall, gas-saving gear used to transfer the engine's power to the wheels does not lend itself to brisk acceleration. To accelerate quickly or climb a steep hill, the car needs to have access to lower effective gear ratios. Those lower effective gear ratios are available only in Hybrid Drive mode, when higher engine RPMs are used to generate power from the starter motor/generator. Honda conceptually refers to this use of a computer-controlled engine+motor combination as e-CVT (electronic Continuously Variable Transmission).

Some day I hope the Honda engineers will reveal how the user-selectable HV Mode chooses between the three basic underlying modes, EV Drive mode, Hybrid drive mode, and Engine Drive mode. It's possible that the fuzzy logic built into the artificial intelligence running our Clarity PHEVs cannot be explained with a simple set of rules. Programmers of high-level chess-playing programs often have no idea why their programs make the moves they do. The good thing is that it all seems to work in the Clarity PHEV.

 

For those of us in cold climates, a really simple improvement that would be a game changer is to have a heated steering wheel. Honda already makes this exact steering wheel heated in other Hondas. With the heated seats plus a heated steering wheel, I wouldn't have to turn on the resistance heater except when the temp drops below 20 degrees F. That resistance heater is the biggest range killer.