Specific "Mission Profile" suggestions?

Congrats on the car! I sense some experimenting coming up. For either route, I’d suggest starting with an almost fully charged battery (<80%) and using HV mode the entire trip. Post back on which works better for your Clarity’s performance!

I don’t use ECON at speeds of 55 mph or over at all. The wind resistance kills the battery fast.

 

You'll find out very soon as you actually drive each but here is what I'd predict:

Effect of hills and/or altitude: Physics dictates that every time you put energy into the battery and pull it back out, you lose energy with each conversion. (Not as much as if you don't have a battery to store it in at all--that's why regen is better than nothing--but it's still a loss). However, to put energy into altitude (potential energy) and then get it back out as speed (kinetic energy) is actually lossless. This is why a pendulum in a vacuum could swing nearly forever.

What this means is that to a first approximation, hills are OK as long as the downhills are not so steep that you are actually charging the battery on the way down. (That's putting potential energy into chemical energy--a losing proposition). If the hills are gentle enough so you just reduce demand on the engine and/or battery as you go downhill, but are still drawing from the engine/battery overall to fight wind resistance as you go down, then you don't need to worry about minor ups and downs in altitude--don't sweat the hills. (I'm ignoring efficiency here as the Clarity does a good job keeping that high).

Twists and turns: No idea, but if you have to actually brake to make the turns that's an energy-losing proposition.

Distance and speed: Longer is of course worse, but faster is MUCH worse (wind resistance goes up with square). If the twisty road is slower and shorter, it might actually be less energy.

All this is just for fun. You'll let US know once you have driven them each way a few times.

 

I hadn't thought about disabling ECON at highway speeds. Can you help me understand why that matters? Thanks.

 

What @Sandroad likely meant was he doesn't use ECON Mode without also invoking HV Mode at highway speeds.

When you first press the ECON Mode button, you'll see a leaf icon in the upper left of the dash display. Press it again to turn off that leaf icon to put yourself in NORMAL Mode. NORMAL Mode doesn't use all the energy-saving techniques that ECON Mode does, but when using Adaptive Cruise Control (ACC), NORMAL Mode accelerates faster than ECON Mode after ACC slows for a car you're following.

HV Mode works with ECON, NORMAL, and SPORT Modes. It tells the Clarity you want to use the engine and preserve the charge in the battery for later use. HV CHARGE Mode is there to recharge the battery (at a significant fuel economy hit) up to 58%.

 

^^^This. Insightnan is correct and I should have been more specific.

 

Thanks! That makes sense. I hadn't thought about turning off ECON to get faster ACC speed recovery. I've been just manually hitting the gas pedal to recover speed, but having the car do that automatically would be more convenient. Thanks for the hint!

 

Congratulations on joining the Clarity Club and ditto on the above posts. The more you drive the Clarity, the more I’m sure you’re going to love it.
I hope you will try the trip coming and going both routes and keep records. Then you will be teaching us!

I’ll share from my limited experience over 9 months and 7,000 miles with just 2 HV out of town trips. As @Sandroad mentioned, highway trips with a full or nearly full charge in HV gives the best experience with respect to economy, quietness (no angry bees), and power. After a full charge, I started my trip in HV over rolling Interstate hills (I75 s, Lexington to Corbin KY) and windy significant hills (Corbin KY to east TN). I got 49 mpg (48 after accounting for small use of battery). And I got only a very moderate mid rpm when going up a long significant climb. Haveing plenty of charge gives the algorithm freedom to switch between its most efficient power flows and gives a much more pleasant driving experience.
If you want to squeeze every last drop (or electron) of economy out of your new PHEV, you can HV on the trip and switch to EV when in EV range of your destination.

If you want to run a proper experiment (and we hope you will and post results), then record all gas, kW used, and miles in HV or EV. Then you can calculate MPG and MPGe.
For your first run, may I suggest staring with a full charge and tank, and then starting in HV and staying in HV all the way and then record gas and kW at destination. Slightly less efficient, but makes for an easy calculation. Post the miles, gas, and kW and I can show you a couple of ways to do the calculations that I learned on this forum. Of course to see which route is more economical, you would have to average a couple of runs, and try to keep the conditions the same, like , cargo weight, weather, speed, heater use, etc.) that will be the difficult part).
If your EVSE doesn’t record kWs and you don’t have a Kilawatt type device for your Level 1 EVSE, then just record the % SOCs (start and end) on Honda Link and we can approximate from there but with much less accuracy.

Looking forward to hearing how your first trips went.

PS: Make sure if you stop along the way to select HV when restating. It won’t remember and will restart in “EV” mode.

 

Just a plus-one on HV mode, from the start. If I'm doing more than 50 miles in a charge, I use HV on the highway and not-HV on surface streets or in stop and go on the freeway.

I use ACC and the Lane Assist on the freeway.

I use Econ mode in city driving, but have it off for freeway driving so that the ACC recovers decently. You'll see posts that talk about using Sport mode to get the quick recovery, but I've not 'normal' (not Econ/Not Sport) mode sufficient.

 

For my long-distance HV excursions I made a paper button (below) that I tape over the D button to remind me to switch on HV Mode every time I get back in the car. It's very disappointing to realize you've been using up your battery charge for the past 30 miles when you meant to be in HV Mode. The situation causes desperate thoughts, such as "Should I engage HV CHARGE Mode?" or "Do I have time to go looking for a public EVSE that doesn't already have a Tesla hogging it?"

 

That☝, a thousand times, that.

 

I printed a copy of this for my "D" button on longer trips. Thanks

 

So true, I had the same thing with my 2012 Prius Plugin. Having had 6 years of practice, I have gotten better at remembering, but still used to falter every so often.

 

What exactly are the energy saving techniques used by ECON mode?

 

In ECON Mode the accelerator mapping makes you press further to get the same acceleration available in other modes. However, if you floor the accelerator, you're getting as much acceleration in ECON Mode as in NORMAL or SPORT Modes.

The click in the accelerator pedal separates electric operation from engine operation only in ECON Mode. In the other two modes, the engine starts before you reach the click point.

The air-conditioner system operates less aggressively in ECON Mode. In cold weather, when you start the Clarity PHEV in ECON mode the driver's seat heater comes on at its lowest setting to encourage you to leave the electric resistance heater turned off.

When using the Adaptive Cruise Control (ACC) and your Clarity slows due to traffic in front of you, the acceleration back to the designated ACC speed will be slower in ECON Mode than in the other two modes.

 

I thought I felt the seat heater on, but no indicator light comes on when in this mode? Based on your info I'll stay away from Econ and just operate the seat heater myself, as the re-acceleration to the designated speed is really annoying and at times unsafe on the highway.

 

We keep our Clarity PHEV in ECON Mode and when we start up in cold weather, there is 1 of the 3 LEDs in the seat heater button lit. I don't believe the seat heater ever operates without displaying at least one LED on the button.

I agree that allowing ECON Mode-level ACC re-acceleration could be dangerous when there are impatient cars behind you. However, I treat it just the same as when I'm driving without ACC engaged. If I see traffic behind me after slowing down I use the accelerator pedal to get back up to speed more quickly.

ECON Mode forever, baby! (Said the fanatic who's been driving gen-1 Insights for 19 years)

 

I believe that you were in NORMAL mode before you pressed the ECON button the first time.

 

There is always at least 1 of the 3 red bars lit up on mine when the seat heater is automatically ON in ECON mode when it is cold. On really cold mornings, I have seen 2 bars instead of 1. From there you can turn it up warmer or turn it off if you don't want toasty buns.

I always drive in ECON because I don't want to trigger the ICE when accelerating to merge onto the highway, which I was finding was happening in Normal mode but does not happen in ECON. I don't find any difference in the actual acceleration, just that the point of turning on the ICE is later.