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2018 Honda Clarity PHEV Review Part 2 – Impressions and Cold Weather Driving


Now that we have put 1000 miles on our 2018 Clarity PHEV I have the answers to a couple questions: how has the car handled temperatures plunging to well below 0F and how have my driving impressions changed?

I have really grown to love the Clarity.  The night I first drove it I wasn’t sold on it, but my wife was going to be the primary driver of the vehicle, so it was ultimately up to her.  So what has changed to make me love the car so much?


The night I first drove the car was on a very cold evening after a cold day when the car was sitting outside unplugged.  Unfortunately, Lithium-ion batteries like the one used in the Clarity PHEV don’t like cold temperatures, it lowers their power output and so I think my driving experience was limited from the car not wanting to draw too much power from the battery.

The sport mode on my 2012 Volt gives the car improved response from the go pedal, and also the Volt has normal (D selected on shifter) or high regen (L selected on shifter) modes.  Many of us like to drive the Volt in Sport with L selected.  When I tried Sport on the first night I test drove the Clarity, I think it was being limited by cold battery with no charge so my opinion of it was somewhat negative.


Driving Dynamics

Now that I have had the car for several weeks, I found the performance of Sport mode on the Clarity PHEV to be very good.  It still won’t set any land speed records, but it will accelerate much faster than most traffic does on a regular basis, meaning it is fast enough assuming you aren’t trying to race people.  It doesn’t have quite as much punch from 0 mph as the Volt, but as soon as it gets rolling it accelerates briskly.

I also found the regeneration improved as long as the battery is warmer.  With the Clarity in Sport mode, if you pull the left paddle on the back of the steering wheel, the regeneration level will increase from 1 to 4 chevrons and stay at the level you set (other modes it clears after a stop).  With the car set at 4 chevrons it is fairly close to my 2012 Volt in L mode.

A few notes, sometimes the regen level will change spontaneously in Sport mode.  If it is very cold out it appears the chevrons will reduce from 4 to 2 after a stop, and setting the cruise control at speed on the highway will also cause the regen level to reset.  Finally, setting the car in park will cause it to reset.  There might be other cases I don’t know about as well.

Camera and Sun

The backup camera has a few modes: ultra-wide, wide, and straight down.  These modes are all from the same camera, but they have different processing to the image to show different things.  Sorry if I get a little technical here, it is my camera background.


The ultrawide view is basically an orthographic fisheye view that shows everything the camera sees.  This adds a circular distortion to the image, but gives you the widest possible view and the benefit to this fisheye view is that scales of objects seen will be accurate, but they will have curvature to them.  The outside corners of the screen are cut off and everything is curved.


The wide view is something like stereographic fisheye projection.  It corrects some of the curvature out, but tries to keep scales accurate.  This view makes smaller objects easier to see and straightens everything out significantly, but you lose field of view to the sides.


The straight down view is a near rectilinear, but still has some fisheye distortion, of the bottom part of the image.  It really helps if you are parking up against something very closely and need to see how your bumper lines up, but you lose all your backwards view.  Only use this for the last few feet in a difficult spot, not for backing out of your driveway onto a street with traffic.


What happens if the sunlight hits the screen and instrument cluster?  For one, the center screen will show any fingerprints that might be on it. Gross.


The instrument cluster is better, but does wash out.  The import information is still visible, like speed, but some other lighter color text disappears, like READY indicator, etc.  The center screen is angled such that the sun rarely hits it and reflects in your face, but when it does it is glossy and reflective.



Low Temperatures

At low temperatures, the Volt runs in a special mode known as Engine Running Due to Temperature (ERDTT).  At low temperatures (25 F on my 2012, 15 or 35 on the 2013 or newer) the engine would automatically start and cycle between battery and engine+battery.  The engine would never really get hot in this mode, it is essentially being run for waste heat, although surplus energy is still put in the battery.


The Clarity PHEV also has an engine running mode at low temperatures, but it is a little different.  It essentially runs in hybrid mode where it runs the engine much more often, but it still pulls energy from the battery.  Notice in the above image, the blue bar has disappeared from around the edge of the speedometer and the EV text is no longer under the READY indicator.


At other times, the blue indicator is shorter, this happens when your battery is low for sure, and I am uncertain if it happens at any other times.  I think there is a bug in the range calculation when driving in low temperature ERDTT mode since it uses both gasoline and electricity.  I think the range will correct quickly once the battery is low, but given it has some history built in I would expect it to have half this range on the highway.

I haven’t been able to determine exactly what causes ERDTT in the Clarity, but it seems like it is related to battery temperature.  A few days I drove around with temps from 6 to 8 F and it never started, and other days it started at similar temperatures.  With high temperatures around 0 F, it has been running much more often.

I actually prefer how the Clarity does this as the Volt cycles frequently at low temperatures and makes for an odd driving experience.  The Clarity PHEV starts feeling like a normal hybrid and doesn’t have the temperature swings in the climate control that the Volt has in this mode.

I have seen charges limited to 4 kw charge rates in cold weather, slowly increasing sometimes.  I haven’t confirmed if this is the car limiting the charge rate of the cold battery, but I suspect that is the reason.  If I charge after driving the car around for a while it charges at 7.2 kw, but if I plug it in when the battery might be cooler it seems to charge slower than that.  It is possible it is the EVSE, but I don’t think it is.


I have also had more time to use the advanced safety features like the LKAS, ACC, AEB.  I really love the adaptive cruise control.  I know this feature has been on cars for a while, but being my first car with it I have a few comments.  On steep curves, the car might stop seeing the car directly in front of it as the radar starts to point away from it.  Also, make sure a car is registered as being seen or you might get unexpected results from some of the other systems.  The radar won’t detect a stopped car either, so don’t count on it to stop you at a traffic light.  The automatic braking might help there, but best not rely on it.

The LKAS shouldn’t be relied on to keep you 100% in the lane, even with decent lane markings.  Depending on how visible the line markings are, I found it wanted to hug and even slightly cross the lane on my freeway I was testing it on, driving towards the middle of the road.  It did warn me I was crossing the line before I did, but it let me cross 6″ or so before it corrected me back.  It would sort of bounce along the dashed line in this fashion.

This effect might have been in part because solid white lane marker on the edge of the road was under snow and the car was trying to keep me from driving off.  Overall, I think LKAS will be valuable but don’t try to let it drive the car without your attention.  My main complaint with it is you will feel the wheel making small jerky corrections frequently.  They aren’t felt in the car, but through the wheel.

The system also monitors if your hands are on the steering wheel, but I found in the cold with the bumpy roads here it seems to not detect this accurately and I was able to leave my hands off the wheel (in very close proximity) for several minutes.  This let me feel how the lane keeping behaved, but I wasn’t able to see what happens if you don’t use your hands.

The included tires are acceptable on snow and ice.  They won’t compare to a good snow tire, but are respectable for all season tires.  It also helps that they only have 1000 miles on them.  Brisk acceleration will make them slip, especially if surfaces are wet or slick.

When the brake pedal is pressed hard on ice, the car provides no feedback that ABS is being used.  It stops smoothly with minimal pulsating as some systems feedback through the pedal.  The stability control kicks in quickly when the steering angle doesn’t match the direction the car is traveling, quickly reacting to slow the car and allow it to turn as needed.  The Volt always let the car slip to the outside more than I care for before the stability control would engage and correct (meaning you slide into the outside of a roundabout if you don’t slow down yourself).


After having the Clarity PHEV for 3 weeks and 1000 miles, I find that I really like the car.  The comfort level is amazing, the power delivery is good enough that I don’t feel it is lacking for daily driving.  The engine runs less than I thought it would in low temperatures, but more than I thought it would at very low temperatures (less than 10 F).  I am growing to like the car in any mode, but Sport with 4 chevrons of regeneration is my favorite.  I can’t wait for the temperatures to get above freezing, but we aren’t supposed to even see 10 F until next weekend.

I wish Honda included a battery heater in the US model to help efficiency at low temperatures, but overall it drives very well, even in the frigid Midwest.  I have only put 4 gallons of gas in it during the time I have had it.  Not too bad considering the Minivan would have needed 55 gallons!!!


To be fair, I have used about 300 kwh of electricity according to my Charge Point Home 32A charger (I love the smart features of this charger).  This is about $33 worth of electricity plus $10 worth of gas, vs about about $137 worth of gas the minivan would have used over the same period.  It has cut my operating expense by at least 3 times.  I am pleased.


26 thoughts on “2018 Honda Clarity PHEV Review Part 2 – Impressions and Cold Weather Driving Leave a comment

  1. Hey, any comments on how this thing handles in the snow?

    Also, and completely separately, I am impressed by these numbers (1000 miles with 4 gallons), but I wonder: are you using the car mostly in the city, so that you almost never engage the hybrid? I am looking into this car, and my commute is 24miles each way on a highway, so I am curious what my real mpg would be. According to my calculations they should be more around 80mpg all included (EV part and Hybrid part).

    • Snow is fine, it handles like a typical FWD, think Accord or similar. I drove mostly shorter trips, longer trips will use gas of charging course.

      I notice the engine runs a lot more in the very cold weather, around 0F or less. Around 32F expect reduced EV range, maybe 35 miles. High speeds will also reduce range.

      In warm weather at speeds 65 mph or less you should make your entire trip or close to it on EV. Around 32 F or less you might use half a gallon of gas (guessing).

      Hope that helps, and I hope it warms up soon in Iowa, want to drive it more 🙂

      • Thank you! I live in Chicago, so I feel your pain concerning the temperatures. I might wait until the end of the month to make the switch. Hopefully temperatures will be less frigid then. My commute is 48 miles return, 15 of which in heavy city traffic and 35ish of highway at 55-60mph. We shall see.

    • Make sure battery is at least partially charged, play around with controls some before driving, it is unlikely they will know anything about plugin aspect.

      You can disable the camera on the mirror when you put on the right turn signal, it gets annoying quickly.

      Drive and have fun. Try the different modes, maybe regen paddles (quick presses change level, the regen level cancels after each stop unless in sport mode).


  2. Hi i am looking to purchase Ă  clarity phev, i have to communte 28mile to work where i Can recharge, i live in Canada(battery heater) and i have a garage, do you think that 28 is achievable at 60mph in 10F weather if the car is preconditionned. Thanks alot

    • I would think so, but unsure how much engine running you would get. I think battery heater would make it possible to run EV only, but you might ask to take one for an extended test drive. The Clarity doesn’t indicate how it handles old fuel either, might just randomly start engine for a bit.

  3. HI,

    Got mine last Sat.

    Just want to share this but tips and tricks and comments are highly appreciated.

    Cruised at 100 km/h (62mph) last night for about 18 km (11 miles) at -10°C (+14°F). It was all electric.

    Ran out of battery in a residential area and I turned off the heat just before that. Gas engine kicked in seamlessly while car was running at 45 km/h (28mph). Stopped at a red light. Gas engine stopped. Turned on the heat at lowest fan speed and set at 16.5°C (62°F). Gas engine started again and was quite loud. Battery was being charged while gas engine was running. Turned off heat and engine stopped.

    Was able to continue pure electric for another 500 m at around 40 km/h with heat turned off.

    Was it because the gas engine was cold that it was running so loud?


    • Hard to say, since it is a CVT of sorts, gas engine RPM is not tied to accelerator pedal input.

      It might be the electric buffer was low, look at gauge on far left, it maintains 2 bars after battery is low, if it drops to 0 or 1 it might run the engine hard to replenish it. Also, strong acceleration can trigger it to run hard.

      • Thanks Viking79.
        Btw, for our information, when the engine was running crazily, the car was at a stop and the battery gauge still has 2 bars but EV range was at 0.0.
        I guess it’s like you said that the engine was running hard to replenish the battery and at the same time power the heat.
        But it is interesting that the engine kicked in and running quietly when I ran out of battery at 45 km/h (28mph) with heat off.
        Seems like heat was the culprit … ?

  4. It is possible, the engine is efficient at producing heat. My wife has complained of similar happening to her too, only after battery is low. It seems to me it shouldn’t rev so much at a stop if batteryg buffer is okay. Could be a software glitch.

  5. Thanks Viking79.
    I should have kept the heat on,let it run, and see if it would quiet down when traffic light turned green and car started rolling forward.

  6. After testing my new Clarity for several weeks, I can add to your valuable comments. This car is FANTASTIC and interfaces with my IPOD music player & Cellphone music files perfectly. Voice commands can be used to select any music I want. Touch-screen menu for my music files are amazing. No more expensive satellite music for me !!! I have no problems getting 48 miles or more in my mild climate (55 to 65 ) Phone calls using the Clarity is awesome. It copies all of my contacts from the cellphone, and can make phone calls using voice commands. I have driven 255 miles and the gas gauge is still full. 90% of my driving is 45 miles or less. It uses Bluetooth to interface with the cellphone, and uses the USB ports to access my cellphone+IPOD music files. High heat settings will definitely reduce miles in Economy Mode. I don’t know yet how A/C will affect EV driving. I’ll report back in the summer..

    HUGE problems when tracking yellow lines and sharp turns. However on expressways with gradual turns the lane tracking has been flawless. Also I have barely scratched the surface of everything that the computer screen can do. It will take a few months of diddlling with the screen to learn it all.

    I LOVE the roominess in this car. Lots of legroom & headroom. This is the only car I’ve had where I have to move the seat forward to be comfortable. Automatic seat adjustment for 2 people is ideal because my wife always moves the seat forward to drive. I love the seat belt can be raised up along the door post for tall people. I LOVE the solid, quiet ride. This rides like a Cadillac. I also love HondaLink where my cellphone displays battery charge and can control climate control + much more. The 12 volt power socket for the rear seats is also a nice feature


    • Regarding the Honda Sensing feature, I chuckled one day when I was at a major intersection. I was in the far left turn lane and as I was making the left turn, the opposite direction left turn was also making its left turn. My Clarity started to give a brake warning and try to slow because it sensed a head on collision, but it stopped after a moment.

      I love the Honda Lane Assist on long drives. It is helpful and 80% of the time, it functions great. This is not an auto pilot, so you do need to stay alert for when the painted lanes break up, etc. IF the car in front of me slows down, the Clarity automatically slowed down. Then it increased back to my cruise control speed once the other car sped up.

      • Autopilot has the same restrictions that you need to stay alert and hands on the wheel. The issue with AP is while it is technically better than Honda Sensing it might be more likely to lull you into a false sense of security since it still doesn’t make advanced driving decisions. Just like the Honda it might follow the wrong line and drive you into something.

  7. Thank you for this article. I live in the Boston area and my commute is 20 miles each way (18 miles if which are highway. I usually do 65-72mph on the highway). While at work the car is parked outdoors, not charging. I intend to charge the car overnight every night. My concern is with the winter. I understand that the driving range for electricity will go down significantly, but what I don’t want to end up having to do is fill the 7 gallon gas tank every few days. Given my scenario how long do you think I will be able to go in between fills in the winter?
    Thanks for your help!

    • Even if you only get 25 or 30 miles range in winter on electric (you can do better than that if you preheat the car) you would still burn less than 1/2 gallon of gas a day, so you would still only have to fill up every couple weeks. I am guessing worst case, about 25 mile electric range and 30 mpg gas would be a full charge and 1/2 gallon. Realistically, I think you would do better than that. You might get more like 35 mile electric range and 40 mpg on gas at those speeds, meaning like 1/8 gallon gas per day.

  8. viking79,
    Can you advise , when you press the accelerating pedal and the cold gas engine comes on, how come its able to provide instant power ? That kind of defies everything I know about not to do to ICE. Normally they need some kind of precondition . even the prius hybrid will turn it on for some time , to warm up the engine.

  9. what if its too cold for my 2018 clarity to even start? just bought it in august and now its gotten to the 30’s temperature and it wont start, no lights no nothing when i push the on button.

    • Mine started fine at -20 F no issue. Sounds like there is something wrong with yours (probably 12V battery related) call service department.

  10. Why is m’y clarity in Québec minus -15celcius drop range from 78km(summer) to 38km(winter) very arsh différence m’y 2017 Volt was summer(89km) winter (69km)
    Same Road same driving style.
    Thé clarity is putting a big whole in m’y gas budget.
    Im somewhat regretting m’y Volt this winter

    Dealer reseted thé car only got m’y 78km rangé 1 day right back at 38km

    • Is your car plugged in to an outlet over night? Is it a Canadian model with battery heater? Do you use different heat settings between the Volt and Clarity? There are a lot of factors, my 2012 Volt would do anywhere from about 25 km winter to 75 km summer.

      How much total gas are you using vs the Volt? The Volt would start the engine at warmer temperatures than the Clarity so could make a difference there.

  11. Question regarding the computer. I’ve owned my Clarity for 10 months and have about 11K on it. On the estimated miles remaining for electric range, it will say 38 (or whatever). Under that, for the hybrid vehicle rangevwhen the tank is full, it will stay at 1,000 miles of range remaining. I’d like to reset that when I fill the gas tank so it is not reading from previous tanks, but instead only shows how much total range I can go with the total amount of gas and electric charge still in the car. Any idea if I can reset the range computer?

    • There are several updates to the Clarity, go complain to your local dealer that the HV range is displaying incorrectly and they will update the car. There are a few outstanding service campaigns or my dealer called them recalls, might as well get them done.

  12. Glad I found this post. We replaced my wife’s 2005 Scion xB (209K miles) with an ’18 Clarity two weeks ago. Today was the first time the gas engine kicked in with 2 bars remaining and she kind of freaked out. I thought it was a safety buffer and that’s what it seems to be. Nothing on the official Honda site; wonder why. Anyway, here in El Paso cold is not really a consideration but I am interested to see what month after month of triple digit weather will do to EV performance. Thanks for all the data in your post!

  13. I live in Canada and have been driving my Clarity for 9 months with 35,000 km driven. Here are some of my comments, observations and dislikes:

    1. I get close to 90 km range in summer, less than half of that in winter (-20 deg C). Of course winter range is strongly affected by seat warmers, front and rear defrost and heat levels. I do notice the heat is automatically adjusted (usually down) in the ECON mode to conserve energy. Sounds like the smart charger mentioned above would be useful to determine how much the charge is reduced in the cold from the 17 kwhrs in summer. I charge outside vs inside.
    2. I find the front defrost (both the button and the climate panel) only works on the outside air input. Would be nice if the rear defrost turned off after say 10 min. I usually turn it off manually asap.
    3. The capacity of the winshield washer tank is quite small (approx 25% of washer container). Becomes annoying on winter drives especially when you are carrying the bottle anyway. Also the delivery of the fluid to the windscreen is flawed as it is wiped away as soon as it is applied leaving upper and lower portions of the glass still dirty. This may be a faulty spray nozzle.
    4. Once, when it was extremely cold (less than 20 deg C) the central touch screen did not work. This may be a faulty screen. Hasn’t happened again.
    5. I have had both the radar and lane detection sensors shut down due to ice and dirt buildup on the exterior of the car. All auto systems shut down when this happens. I find the collision avoidance system can easily be tricked ‘on’ (and apply brakes) usually when turning at highway speeds around a gentle right curve where the oncoming taffic can be directly in front of you. A question for you; do the brake lights come on when these automatic systems apply the brakes? Also, do the brake lights come on when the regen paddles are used as this can slow the car fairly abruptly?
    6. The autonomous driving features make for a much more relaxed driving experience both at highway speeds and stop and go trafic. I do not think either the rate of automatic brake application (too abrupt) or the rate of acceleration after clear traffic (too slow) is optimized. With the radar locked onto the car in front, brakes are not applies until the last minute. Only with relatively small changes in car speed does the system seem to work well. Maybe this will be corrected with the upcoming software updates.
    7. The timing of the gas engine application when the EV is used up can be optimized. Seems when it hits two bars the engine come on at high revs after a nice quiet electric drive. Why is it not programmed to come on a little sooner at a lower, less noticable, rev level. Find this is also true when accelerating at a low speed (less than 40 km/hr). I had one situation when the EV was actually down to one bar and the gas engine seemed to hit the rev limit. Not good.
    8. The lane keep assist works well most of the time. The system must average the cars position between the two lines. I have noticed when one of the two lines disappear the car will steer slightly toward the side with no line then go into flashing mode. Sometimes I turn this system off to have a rest from these constant steering adjustments. This seems to depend on the quality of the road.
    9. A few other bug-a-boos: The armrest/compartment cover interfers with a cup of coffee in the cup holders. The height of the front portion of the trunk is too low. Raising it would improve the volume of the trunk. Dashboard rattles on rough roads. Not sure I should have the dealer try to fix it. May make it worse. Always getting the back of my pants dirty as I step out of the car. The range calculation is confusing. I have had a range of 1,800 km displayed. Not at all realistic.
    10. Things I love about the car: Not putting gas in my car in town. The fuel economy off EV is still a respectable 5 l/100 km.The quiet and solid ride. The luxury level. The weight of the car adds to winter traction with good winter tires. Space for five adults.

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