I've had may Clarity about 7 months, 4500 miles. It has been as "constant as the northern star" to quote Khan or Julius Caesar or Shakespeare or whatever.... It's been since before Christmas that I have taken a road trip to run the ICE/burn any significant gas. This week on my daily commute, the car has started the ICE 3 different times on the way home, always at the same place and burns about a cup of gas, nearly nothing. The first time, I assumed I had been aggressive on the accelerator. But today, I am certain I was babying it when it switched to ICE. All three times MPG still showed well above 100 MPG by the time I get home on the trip computer on a 6 mile commute and car had already cycled back to EV by the time I got home (just ran a couple of miles on ICE). I am assuming it is just fussing over the age of the gas in the tank (about a half a tank since probably early December) and trying to sip some out a little at a time. Anyway, again, I wish the engineers would have "lit a single candle" for us on this one, but they elected to keep us "forever in the dark"...
MPG display means nothing at all in this PHEV. I'm curious, too, but absent the details I try to simply enjoy. Sent using Inside EVs mobile app
Once again, I'm reaching out to Honda (they read every Clarity forum post, right?) to create an optional mondo-info screen. I would pay hundreds to see (among other things) a real-time graph displaying the factors the Clarity uses to decide when to start the ICE. Including a logging function with this optional app would help people experiencing the mysterious power-loss problem determine what happened then the power disappeared. Honda, why not make a few bucks while making the Clarity nerds happy? The downside for Honda would be Clarity nerds harassing their dealers with problematic data when the dealers are already overwhelmed by the Clarity's technology.
By the way, I've never had any angry bees or anything close to a loss of power event, so I dearly love the behavior of this car. I've burned 20 gallons of gasoline in 4500 miles with about 900-1000 miles on the ICE engine on highway trips (excluding EV miles on those trips). I drive the car pretty hard, generally trying to cover for the bad reputation hybrids get for being slow (thanks to most of the Prius owners here for that one - sorry if I offended current/past Prius owners). I've never noticed the car before starting the ICE unless I over accelerated (always drive in econ mode, just try to stay shallow of the 3/4 ICE switch level on the accelerator). I really believe it is just fussing over me not burning enough gas in 2-3 months and is trying to push some through the engine. I'm wondering it it will keep up this near daily burning of a cup of gas until I take it on a road trip to make the computer "happy" again...
I don’t think we have any proof that the Clarity won’t let gas get more than one year old as is the case with the Volt’s software. I’ve driven 6 months and over 4,000 miles since my last HV trip without the ICE coming on except for the no regen allowed, ICE operation to protect overcharging scenario. And I’ve learned to avoid even that by using only the pedal and not the paddles, and not braking hard for the first 5-7 miles after charging. My Clarity seems happy to let the gas stay in the tank forever.
I guess it is possible that my deceleration is causing this, since it is right after charging and right after using the paddles/brakes relatively hard for deceleration to make a turn that it has occurred. I assumed that since I had used the battery to accelerate to that level before the deceleration, that it wouldn't be a problem (no downhill) and that there would be room in the battery for any reclaimed energy. I'll be a little softer before making that turn to see if that is the culprit. It is possible that the car is just more sensitive than I knew with regen starting the ICE when it is near 100% charged. Thanks for making me think more about it.
Why does the gas engine come on for no apparent reason? That is a Great question! I’d love to understand why my new Honda Clarity (Storm Trooper) has used any gas. I live in Phoenix Arizona and so far the vehicle shows me a 60-62 mile driving range each morning (no AC or heat being used yet). I typically drive less than 40 miles a day so I do ALL my driving in Econ mode. The gas engine has come on a few of times for no apparent reason so I have used about a gallon of gas in the 1700 miles I have on the vehicle (no fast acceleration, no up hills, no down hill, no low battery, no overcharged battery with regenerative braking). The few times that the gas engine came on was at about 1000 miles on the vehicle. It never came on prior to the first 1000 miles and my driving habits didn’t change. The gas engine hasn’t come on in the last three weeks. The last time the gas engine came on the only thing that I noticed that was different from my normal routine was a friend of mine turned on the passenger side heated seat. The outside temperature was 65°F, the vehicle had an 80% charge, I was driving very conservatively, and in very light city traffic at about 45 mph. In my estimation there was no reason for the gas engine to come on. Does anyone know if there is a “stale gas” feature that would cause the engine to run periodically just so the gas doesn’t go bad? If not… Why would the gas engine come on?
From the owners manual: " Auto Engine Stop/Start The car will select the appropriate source of power depending on the drive mode you select. As a result, the engine will automatically start or stop as needed to either charge the battery or provide supplemental power. Under certain circumstances, the engine may turn on or, if it is already on, it may not turn off. ● You are going uphill or accelerating aggressively. ● The climate control system is in heavy use. ● The Ambient temperature is too hot or too cold. ● The High Voltage Battery state of charge is very low. ● The vehicle is running a system check. System Check When the engine initially starts (between the time the POWER button is turned on and turned off), the vehicle conducts a system check. ● While the check is being conducted, the engine may periodically turn on and off. This, however, is normal. ● The curved blue line in the POWER/CHARGE Gauge will not appear during the system check (EV indicator may still turn on). ● Once the engine starts, it will continue to run until the system reaches operating temperature. The curved blue line in the POWER/CHARGE Gauge will reappear once the system check is completed." The only time I experienced the high rev loss of power was with a full charge after coming down a hill and stopping for a left hand turn. The engine made a high rev sound and I instinctively let off the accelerator. This of course produced a loss of power and some confusion. When I pressed down on the accelerator the car got under way again and within less than one minute the high revs went away. I have also experienced high revs when the temp was very cold (minus 5 F).
Just to offer a little more from a Volt owner's perspective, it (the Volt) insists on running the engine every 6 weeks for "engine maintenance mode", so maybe the Honda has a similar reason. The Volt will give me 24 hours advance notice on EMM and give me the option of whether to do it immediately or defer. As others have noted, the Volt also will burn gas to keep the average age of the fuel in the tank below one year.
Thanks for the feedback guys. I really appreciate your insight and shared experiences. It may be that running one seat heater qualifies as “heavy climate control system use” or Storm Trooper was performing a 1000 mile engine “System Check“ three different times in one week for random periods of time. LOL I only wish that Honda would give more detailed information as to the circumstances surrounding each of the reasons the gas engine could come on. Volts “advanced notice” system is A great feature. I would love to know in advance when the vehicle was going to do a “system check“. I would think that a lot of plug-in hybrid owners are like me and want to do as much driving in all electric mode. This random engine starting takes some of the fun out of the electric driving “game playing” experience.
I don't think so. My experience is that the ICE will always start if the outside temperature is less than about 15°F. I know that this does not apply to you, but I can always get the ICE to shut down in this situation by turning off the cabin heat. The seat heater does not affect this experiment; I can leave it on and the ICE still shuts down as soon as I turn the fan speed to minimum. From this I conclude that seat heater use does not play into "heavy climate control system use". The other factor is that the seat heaters are run from the 12 volt system and use a tiny bit of power compared with the cabin heat. Usual disclaimer: This is my personal experience and maybe your beta Clarity has a different build of the controller software.
