Motor Trend reviews the Clarity

Discussion in 'Clarity' started by Dan McInerney, Feb 5, 2020.

  1. After a quick scan, one flub - we don't have a CVT. It also implies that SPORT mode affects steering - it doesn't.

    Other than that, it seems pretty accurate and favorable.
  2. Mowcowbell

    Mowcowbell Active Member

    "Available for order in all 50 states"... that should read "Available for order in all 50 states if you find a dealer that is willing to".
  3. Goofy way to run a car company, isn't it?
  4. insightman

    insightman Well-Known Member

    I was bugged when MT accepted Honda's claim of 212 hp for the Clarity PHEV. Then I went to Honda's 2020 Clarity PHEV web page and saw an asterisk next to the 212 I'd never seen before. Clicking on the asterisk displays, "Total system horsepower as measured by the peak, concurrent output of the two electric motors and gasoline engine."

    I don't understand this explanation. I doubt it was written by a Honda engineer. When the gasoline engine is running, the starter motor/generator is not contributing horsepower because it's acting as a generator. The only time the starter motor/generator functions as a motor is when it's starting the engine. I don't believe the two electric motors and the gasoline engine are ever concurrently contributing to the total system horsepower.
  5. Tek_Freek

    Tek_Freek Active Member

    Blame Honda. They're the ones that said it has an E-CVT. Screwed with everyone's head.
    Kerbe likes this.
  6. Philemon

    Philemon New Member

    @insightman just to let you know that the ICE can « clutch » in to the wheels to provide the 212 HP . If I remmeber correctly : 121 HP without the ICE, 180 HP with the ICE boosting the electricy drive and 212 with everything.

    Envoyé de mon iPad en utilisant Inside EVs
  7. insightman

    insightman Well-Known Member

    To understand the Clarity better I created this chart to illustrate the various Clarity drive modes. I stuck 212 hp in the box illustrating Engine Drive mode only because it's the only basic drive mode (EV Drive, Hybrid Drive, Engine Drive) for which Honda hasn't specified the horsepower. However, I keep thinking I should erase that number.

    The electric motor is supposedly able to pump out 181 hp (one more than 180) when receiving energy from both the battery and the starter motor/generator being turned by the ICE. When Engine drive mode is in effect, can the anemic 103-hp ICE continue adding 60 hp worth of electricity (including losses) and then also supply another 31 hp to drive the wheels through the clutch? Remember, the ICE is running at lower RPMs when it's connected to the wheels, so it's not generating its peak horsepower.

    If Engine Drive mode is the 212-hp mode, why doesn't the Clarity PHEV then feel like it has 212 hp? When in Engine Drive mode if you come to a significant hill or try to pass another car, the Clarity PHEV opens the clutch, drops out of Engine Drive mode, and returns to its 181-hp Hybrid Drive mode. Why would it have to do that if it has access to 212 hp?

    Honda didn't include Engine Drive mode to blast the Clarity PHEV to its 100-mph maximum as quickly as possible. They added that clutch and those gears because Engine Drive mode provides better gas mileage than Hybrid Drive mode at speeds over 45 mph. It doesn't make sense to me that the most efficient mode of propulsion would also be generating the most horsepower. I want a better explanation from Honda than "Total system horsepower as measured by the peak, concurrent output of the two electric motors and gasoline engine."
  8. Landshark

    Landshark Active Member

    You know Honda isn’t speaking to you.

    How about this: The 103hp, ICE driven generator, with some inefficiencies, is able to provide sufficient electricity that an additional 91hp can be sent to the motor concurrently with the 121hp provided by the lithium batteries, bringing total power output to 212hp.

    I’m not a Honda engineer, I don’t play one on TV and I didn’t stay at a Holiday Inn last night.
    Teslawannabe likes this.
  9. leehoewonek

    leehoewonek New Member

    Also, in the intro, they call it a hatchback. I wish.
  10. I suspect that the ICE driven generator isn't going to be able to provide 91 hp worth of electric power when being driven by a 103 hp engine.
  11. Landshark

    Landshark Active Member

    You may be correct. Do you happen to know the continuous and peak output ratings for the generator?

    The mysterious 91hp certainly isn’t being provided by Direct Drive, which promptly disengages whenever moderate power is demanded.

    My money is still on a combination of peak power provided by both the batteries and generator for brief periods of time.

    Has anyone put a Clarity on a Dyno and run it through its various modes?
  12. Ray B

    Ray B Active Member

    I believe it is purely a marketing thing that someone in the engineering department got fed up with and said 'yeah, write it has 212 hp - whatever'. The Accord Hybrid with the same kind of iMM-D drivetrain but with a smaller Li battery (obviously) also lists the traction motor as having 181 hp, the 2.0L ICE engine as capable of 143 hp, and the "Total System Horsepower" as ... 212 hp. Coincidence?

    Interestingly, they put a "1" note on the 'Total System Horsepower' but there is no #1 footnote at the bottom - it starts at #2. I wonder if someone from the legal department deleted that footnote. I believe the new CRV hybrid has the same 212 hp TSH specs.

    Again, I believe this is all just posturing with Toyota who posts the 'Hybrid System Net Power' of the Camry Hybrid at 208 hp. {No footnote}
  13. jdonalds

    jdonalds Well-Known Member

    Right. Because of the clutch disconnecting the engine from the drive train any time there is a load we never get to experience 212 HP. They shouldn't publish that state because engine drive mode is only intended to take over with low loads.
  14. Phil_Meyers

    Phil_Meyers Member

    I read it as the power is calculated at Vmax and engine at max power.
  15. insightman

    insightman Well-Known Member

    The engine turns slower in Engine Drive mode so it is never at max power then. When the Clarity PHEV is in Hybrid Drive mode, the max horsepower produced by the traction motor driving the wheels is 181. It doesn't seem valid to count the engine's horsepower twice by adding its raw output to the output it is contributing to bump the traction motor from 121 hp to 181 hp.
    Last edited: Feb 7, 2020
  16. Agzand

    Agzand Active Member

    They do, the main motor needs electricity to generate max power, the battery cannot supply that level of electricity by itself. So the second motor generates electricity, which is horsepower. This is of course generated by engine in the first place. What it cannot do is to generate sum of the power of engine and motor together (103+181), because in order for motor to generate 181 HP, it needs some electricity from the engine.
  17. insightman

    insightman Well-Known Member

    Facts not in question:
    • The traction motor can produce 121 hp on battery power alone
    • The traction motor can produce 181 hp on battery power + engine-driven starter motor/generator power
    • The engine is not achieving maximum horsepower when operating at the lower RPMs of Engine Drive mode
    I believe that Hybrid Drive mode's 181 hp is available only when the engine is turning at angry-bees RPMs. If the Clarity produces 121 hp in EV Drive mode and 181 hp in Hybrid Drive mode, the only mode left to produce 212 hp is Engine Drive mode.

    The question is how much horsepower can the engine running at lower RPMs send through the clutch to the wheels while it is simultaneously providing 60 hp to the traction motor? There are certainly losses in the system, so the engine must expend more than 60 hp twisting the starter motor/generator to generate enough electricity to bump the traction motor's output from 121 hp to 181 hp. How much more, who knows? However, if the engine can produce a maximum of 103 hp running at angry-bees RPMs, it's certainly not producing 103 hp running at the lower RPMs occurring in Engine Drive mode.

    Suppose for the sake of 212 hp there are absolutely no losses in the system and the starter motor/generator requires 60 hp from the engine to produce 60 extra hp from the traction motor. Then the engine needs to also send 31 hp to the wheels to get to 212 hp (212 - 181 = 31). So the engine must produce 91 hp (60 + 31 = 91) while operating at the much lower RPMs of Engine Drive mode to arrive at 212 hp "total system horsepower." I find that power total doubtful.

    But what happens when you press too hard on the accelerator pedal in Engine Drive mode? Do you get a 212-hp surge? No, the Clarity drops out of Engine Drive mode and accelerates in the 181-hp Hybrid Drive mode. When does the supposed 212 hp come into play? Never when you're driving the Clarity as far as I can tell. It's just a number in a list of specs.
    Last edited: Feb 8, 2020
  18. Ray B

    Ray B Active Member

    I agree that Engine Drive mode is impossible to produce anywhere near 212 hp.

    I also agree that EV mode can produce a maximum* of 121 hp. {*Note: maximum is only available when the battery temperature and SOC allow for this much power to be drawn from the EV battery; see diagram below for the battery power and regen capabilities as a function of temperature and SOC}


    But in my mind the 212 can in theory be achieved if one can allow that the traction motor can gather up 121 hp from the EV battery (at warm temperatures and at high SOC) and add in 91 hp from the ICE driven generator at high RPMs. Which can theoretically happen if you jam the accelerator to the floor. But I think all of us can agree that this circumstance - even if we can agree for the sake of argument that it is possible - is a short lived event since the stated maximum power of the traction motor is 181 hp. All motors have a maximum continuous power and a maximum peak power rating. Honda only gives a maximum power rating for the motor, so we can presume that the 212 may be something that can happen if the motor is pushed to its peak power. But I think that such a circumstance is very unlikely and is mostly a figure that exists on paper only, and can probably never be demonstrated on a dyno.

    So to sum up such a power rating could only be possible in HV (series) mode, and demonstrating it may be difficult and short-lived or (more likely) impossible.
    insightman likes this.
  19. PHEV Newbie

    PHEV Newbie Well-Known Member

    Although this is comparing apples to oranges, MT also tested the 2020 Subaru Outback 4 cyl that produces 182 hp. The Outback weighs 3752 lbs so it weighs about 300 lbs less than the Clarity. MT tests show that the Outback 0-60 time is 8.7 seconds while the Clarity is 7.6 seconds even with the significant weight disadvantage. This just goes to show that other factors are more important for acceleration like torque (the Clarity is higher than the Outback) and minimal loss of power when you can use a single-speed transmission vs. a multi-speed transmission with a torque converter.

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