how to drive the car

Discussion in 'Clarity' started by victor_2019, Jul 29, 2019.

  1. ozy

    ozy Active Member

    I have stopped worrying about HV and EV modes and when to use them. I have a 66 mile commute each day and have played with all kinds of strategies eg: timing when I turn on various modes etc. Ultimately I began to realize that it doesn't make any difference to me at all. I simply get into the car each day and start my drive. At a certain point the EV runs out and it doesn't bother me in the least. Actually, sometimes I notice that I get a little bit more EV here and there as I brake. I have seen no difference in this way of driving than in meticulously timing my EV and HV modes so that I cruise back home with exactly 1 mile of EV remaining. Actually, the car is so smooth on the freeway that even in the last 15 miles or so without EV, the revving rarely bothers me.
  2. David Towle

    David Towle Active Member

    I think another influence was they had a hybrid algorithm that worked with their non PHEV cars, and they decided for either simplicity or cost reasons or ??? not to change this algorithm much for the PHEV.
  3. neal adkins

    neal adkins Active Member

    For most drive routes this is fine. I noticed a decline in performance after i had depleted ev range and was in a traffic jam and was stopping and going quickly. I dont think It is possible for the car to have the same available hp after the ev range is depleted unless you press past the detent in wich case it may allow additional battery power even if in a very low soc. The only other time i saw a definate reduction in performance is when climbing a 15 mile 6 percent grade. In this case the engine was nit in dirwct drive and revving very high to make the climb. Case closed
  4. metabubble

    metabubble New Member

    I am a new Clarity owner and I decided to only manually put my car into HV mode if I need to preserve battery because I plan to use preconditioning before I can charge again.

    Sent from my Pixel 3a XL using Inside EVs mobile app
    4sallypat and 2002 like this.
  5. tsttm

    tsttm New Member

    I didn't see this mentioned, but I had to share another 'function' of HV charge mode- my friend with a toddler remarked that the car was 'too quiet', resulting in his toddler not wanting to sleep during 'nap time'.

    I never use HV charge, but it dawned on me to add 'white noise' and extra vibration. Sure enough, toddler (and mom) fell asleep within minutes with HV charge on. We all thought it was brilliant, and referred to it as 'baby mode' :).
  6. ab13

    ab13 Active Member

    Honda actually did an internal project on baby "sound sitter," though it didn't involve the Clarity.
    MPower likes this.
  7. insightman

    insightman Well-Known Member

    BMW's press release about the upcoming all-electric MINI Cooper SE hints that they may use fake engine noise as the low-speed pedestrian-warning sound (I like Honda's Clarity angel choir myself).

    > The new MINI Cooper SE develops its sporty flair not only with striking
    > spontaneity but also virtually noiselessly. For this reason it is fitted as
    > standard with acoustic pedestrian protection. A distinctive sound created
    > especially for the MINI Cooper SE is generated via a speaker system.
    > The sound design in the low speed range guarantees an acoustic presence
    > on the road that is typical of MINI.

    BMW has a history of using their cars' stereo systems to impose impressive, but faked, engine sounds on the occupants--I never considered the idea that those engine sounds might be meant to help get babies to sleep. BMW could do the same for the electric MINI. I wonder, are BMW's faked engine sounds more impressive with the higher-option stereo systems?
  8. jdonalds

    jdonalds Well-Known Member

    Yes the car will regen when in HV mode and the battery is almost 100% full. I venture to say the car won't stay 100% charged for very long no matter what mode the car is in. For long trips I switch to HV mode as I enter the freeway, having driven in EV for the 4 miles to the freeway. After that the car behaves like a hybrid, switching from having the ICE run to having it turned off as needed. Even at 75 mph the car will shut down the ICE and go into regen on slight downhills of the freeway (so long as the wind isn't against you). As an aside this is why it is impossible to calculate ICE MPG.
    Kerbe likes this.
  9. KentuckyKen

    KentuckyKen Well-Known Member

    I’ve enjoyed this thread very much.
    I wonder if the engineers and powers that be at Honda realized how much blood, sweat, and tears, and sheer enjoyment among some of owners would accompany their decision to tell us absolutely nothing about how our wonderful Claritys work? I think it might have been just a decision to keep R&D secrets in house especially since there is no marketing advantage in regard to the unwashed masses. But a lot of us atypical owners on this forum would pay good money to sit down with some of the Clarity engineering team.

    I consider the Clarity to be the perfect driving car since you can play and even obsess over all the settings and modes or just get in and drive with nary a care and the results are practically the same the majority (perhaps not always) of the time.

    I have very limited experience in HV mode (~750 miles) but have never had any high reving or loss of power on hill climbs or at any other time. It’s as if mine came with an engine governor set pretty low.
    I’ve used HV at the beginning of all my longer trips but did let EV go to 0 (2 bars) once as an experiment. I can report that at speeds under 65 mph on rolling hills that there was no difference in power modes rotating through on the display or in driving experience (power or noise). Also, in town I could only barely hear the ICE.

    My only question would be if I tried that with the car fully loaded, at higher speeds, and/or up a significant incline would I get the same results? Some say no, @craze1cars says yes but wants more data. Since my Clarity works so perfectly, I’m not going to risk tempting the god of the angry bees by trying. I’ll just keep doing my HV trips with a large beginning SOC which also reduces the depth of discharge metric which just might help the battery longevity.

    My personal, unsupported, and highly subjective opinion is that all this playing with, messing around with, and even obsessing with the power modes, engine rpm and battery health are only going to gain a few % improvement at best. But it does make me feel better and doesn’t hurt or cost anything.
    insightman likes this.
  10. Kerbe

    Kerbe Active Member

    I noted two things yesterday while traveling on the interstate at 74 mph: 1. Once the battery level reaches 2 bars the Clarity automatically behaves the way it does when I select HV mode and, 2. depressing the brake pedal causes the Clarity to regenerate at a much higher rate than using the paddles. Starting from home with a full battery I drove the 2 miles to the interstate and, at the bottom of the ramp, selected HV mode. I then drove 55 miles to the state capitol and, exiting the interstate, turned off HV mode for the mile drive to the office. I then picked up my boss and drove in EV mode to lunch and back - five miles. The Guessometer showed 38 EV miles available so I decided to see what would happen and headed home in EV mode. After about 40 miles the GoM was down to 2 bars (0 miles) and the ICE started generating, switching itself on and off for the remainder of the drive as it would in HV mode. By the time I reached home the GoM had 4 bars and predicted 8 miles of EV range. When I connected the Clarity to the 30A, 240v EVSE in my garage, the AC came on to cool the battery - I"m both reassured and happy that the Clarity knows how to take care of itself.
  11. craze1cars

    craze1cars Well-Known Member

    Well....I’m not so sure I’ve been interpreted here correctly. Your comments above indicate I said you would get the same power or noise whether cruising easy at 65 mph lightly loaded on rollers vs running 75 mph long significant inclines with a heavy load.

    Indeed I have always said there will be no loss of power to the wheels regardless of state of charge of the battery, based on my experiences climbing 12,500 ft mountain passes and doing a 4,500 mile road trip almost entirely in HV and probably 1,000 miles of which had 2 bars on the battery gauge. Not once did it feel like it had less than 181 hp on tap.

    So yes the driving experience never changes in terms of right foot position vs speed/power as some here have speculated without testing. But the noise? It changes. A lot.

    Extended runs with heavy load at high speed uphill will absolutely wind out that 4 cylinder to substantially higher rpms, and it is NOT a refined engine, so you will undoubtedly hear that engine working like a dog...

    I always maintain that the HP to the wheels never drops off in any circumstance, and that letting that engine spin high rpms is harmless for the car. But as for is by no stretch of the imagination a quiet ride when the battery is being tasked over a length of time. You’ll know darn well that engine is running fast and you’ll need to turn up the radio, and unwitting passengers will ask “is this thing ok?” And I will say yes it’s operating as designed. But I’ll even go so far as to say it is likely the least refined sounding engine at high rpms I have heard in any car for the past 20’s not particularly smooth or pleasant.
    Last edited: Aug 29, 2019
    Richard_arch74 and KentuckyKen like this.
  12. 2002

    2002 Well-Known Member

    I have always assumed that any Atkinson cycle engine is going to be noisy when using a lot of power, which is why they aren't used in regular cars, only hybrids where an electric motor is available to assist when extra power is needed. My Gen I and Gen II Prius both sounded like lawnmowers when the battery got run down in stop and go traffic. I drove rental Gen III and Gen IV Prius and never heard that but it could be that I just didn't have the cars long enough to get into one of those situations. I wonder if Clarity is in fact nosier than other hybrids in similar situations or pretty much the same.

    The part about automatically switching to HV when you reach 0 miles is normal, even though it doesn't indicate it on the display. But mine always stays at 0 after it automatically switches to HV at 0 miles, I have never had it climb back up. The SOC goes back and forth from 8-10% but the display just always shows 0 miles. Going from 0 to 8 EV miles in that situation would normally require starting charge mode, which does not happen automatically you have to manually initiate charge mode. Or else there was a whole lot of regen going on, did you have a lot of downhill on the way home?
  13. MPower

    MPower Well-Known Member

    My 2012 Prius Plugin was plenty noisy whenever you drove uphill at Interstate speeds and I am talking about 65-70 not the 75-85 that folks on this forum mention. It just roared. I've only once had the Clarity sound that loud, going up hill with three in the car and luggage and the heater blasting (temps in high 20Fs), driving over 70 with about 1/2 SOC. The row stopped when I slowed down to 65.
    KentuckyKen likes this.
  14. Ditto.
  15. If you're talking about substantial, sustained grades, unless you're making a withdrawal from the battery, it comes down to a 103 hp engine pulling a 2 ton car up the grade. The engine's going to be working hard.
  16. craze1cars

    craze1cars Well-Known Member

    You are ALWAYS making a withdrawal from the battery when climbing steep and extended grades. The engine is fully disconnected from the wheels and 100% of propulsion is coming from the electric traction motor. This cannot be overridden or user selected. Indeed the engine is running at very high rpms during this time.
  17. My point was that when in charge sustaining mode (either in HV mode or when the battery is depleted) the battery isn't contributing anything to the propulsion. Effectively, all of your propulsion is coming in the form of the 103 hp engine driving a generator which is driving the motor, with no help from the battery.
  18. craze1cars

    craze1cars Well-Known Member

    I understand what you mean to say. But honestly I disagree. In charge sustaining mode the net effect is zero on the battery, yes. But that’s net. When going uphill the battery is drawing down, and when going downhill the battery is getting charged back up. But the battery is always contributing on every uphill. And therefore there is more than 103 hp available during those uphills. The battery will catch up on the next flat or downhill or even during more gentle uphills by spinning the engine at faster rpm. I firmly believe, and have felt, that 181 hp available on every uphill regardless of steepness or duration. Because on the downhill it might be expending only 20 hp or even zero hp and adding regen back into the battery while the engine is still spinning at high rpm assisting on the catchup phase.

    For example we reached the top of a 12,400 ft pass last fall and pulled over to an overlook for photo shoot...just 2 adults but back seat and trunk had hundreds of pounds of luggage and food for a 3 week trek. As I brought the car to a stop the battery gauge showed one bar, the car was at a dead stop, and the engine was spinning not full throttle like earlier in the run but still 3000 rpm I would guess? It was essentially in a self induced charge mode catching the battery back up to 2 bars where we had started the climb. But it had enough gonads even with low battery to make that climb just fine, albeit engine was likely spinning 5000 rpm most of the way.

    Your explanation implies you only have 103 hp to get up long mountain grades. In my multiple experiences driving up long passes, and sometimes flooring it to pass slower vehicles that are struggling to make the top, it feels as though it has more than 103 hp on tap every time, whether battery is full or at two bars. Obviously I don’t carry a dyno and can’t quantify this. But I’ve driven some of these passes in NA 4 cylinder cars before that legitimately have 100 to 120 hp and are much lighter than Clarity, and some have struggled to even maintain 60 mph with foot flat to the floor. Clarity has a notable bit extra to spare, and is heavier. It feels like a 181 hp 4000 lb car should
    In those circumstances. If only engine power was available, understand it is mathematically reduced to about 66 hp at 12k feet in non turbo applications. see )

    If only 66 hp was available to move the car at 12k ft, a 4,000 lb car could NEVER maintain highway speeds, much less accelerate while climbing. Yet it does with engine fully uncoupled from wheels. The only possible explanation is because the battery is providing propulsion in addition to the screaming generator engine, and it has enough reserve to do so even with 1 bar showing on the battery gauge.
    Last edited: Aug 30, 2019
  19. 2002

    2002 Well-Known Member

    In charge sustaining mode it will draw on battery power for acceleration then when the acceleration is over it will usually start recharging to try and get back to target SOC. For longer accelerations the theory that you are proposing (which I don't doubt) is that it will allow SOC to drop to a lower level as long as the acceleration continues. EV range of 0 is about 10% SOC and in normal driving it seems to not allow it to drop below 7 or 8%. However a couple of times when I have been parked with AC running it drops down to 1% before ICE comes on to recharge. So in theory in a hill climb you could have roughly 9% SOC available to contribute to what ICE is already doing with all of its screaming, so that could be providing the power that you feel that you are experiencing. Of course it can't keep that up forever without dropping below 0% SOC, which it certainly could as I am sure there is still some charge left at 0% SOC, but I tend to doubt it would go below 0%.

    The app will show SOC although it's not really safe for the driver to be monitoring it because it take a lot of button pushing to keep it updating, but a passenger could. I don't know if the OBDII apps like Torque Pro show SOC. If you could monitor SOC during a hill climb it might help confirm or invalidate different theories.

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