Insightman, Seriously your contributions here made a lot of clarity owners less frustrated and made their car much enjoyable. In a general case, no one needs to know all these. But clarity seems pretty much a engineer's car(for lack of better term). Sadly it needs some explanation of how this hybrid system works for most folks to realize the importance of battery charge. Honda might have chosen to make this better by increasing the battery reserve but opening only 35 miles of Ev range as pitfall. This is old, but Alex also explain this a while ago. One of my early attempt to understand accord hybrid.
Alex is my hero (along with @KentuckyKen ). Alex really understands how to make things understandable.
One clarification needed. Where is this gear icon of which you speak? I've looked for it both on the car and in the manual and cannot find it. thanks
Haven’t seen mine in a while, but I’m pretty sure it illuminates between the engine icon and battery gauge on the vehicle energy screen at the intersection of the energy flows to and from the engine, wheels and battery. You’ll only see it in HV when the engine is running with the engine icon is illuminated. Mine goes on and off on multiple times on the interstate. It has a narrow torque and specific rpm range so hills will cause it to declutch and you won’t see it below 50ish mph.
@KentuckyKen is right. I tried to blow up the illustration from page 14 in the Owners Manual. The illustration is so small that it just got fuzzier. So I drew a red circle around the icon so you can at least know where to look on the Energy Flow screen.
Ok I will put that screen up and watch for it. Unlike most of the people on this forum most of my driving is not in EV mode but in HV so I want to understand how that works better. 40 miles doesn't get me very far most days!
I had the same question about the location of the gear icon. Today I finally figured out where it was and why I hadn't noticed it before. Usually when I am in hybrid mode, I have the Android Auto screen on. Driving home, I had the Energy Flow screen on in HV mode and noticed that at the junction of the engine and motor energy flows to the wheels there was a tiny tiny tiny thingy which came and went. Bingo, I realized that this must be the gear icon everyone mentioned. Let me tell you, the only reason you never noticed it is because you were driving without a magnifying glass.
I find this part of your quote interesting. My experience with salesmen is that they will say a lot of things to sell a car, not all of which are correct. Case in point, my wife drives an Acura which recommends 91 octane fuel. She routinely puts 89 octane fuel in it "because the salesman said it was okay". Someone once told me the moon was made of green cheese, too, but that doesn't make it so. As to using HV mode on the highway, I know that many on this forum advocate doing what the salesman told you, but I disagree. To summarize, most say to use electric mode to get to highway driving, HV mode on the highway at highway speeds, and save some battery charge for driving on city streets at the destination. I find this technique to be exactly the opposite of what I want to do. Here is my thinking: The Clarity is rated at 44 miles per gallon city driving and 40 miles per gallon highway. For me, gas is now about $2.20 per gallon and my electricity cost is $0.139 per kilowatt. Since a "full" charge is approximately 15 kilowatts, the rated electric range of 47 miles costs me $2.085 or $0.044 per mile (15kW x $0.139 = $2.085 / 47 miles = $0.04436). At $2.20 per gallon, city driving costs me $0.050 per mile ($2.20 / 44 = $0.05) and highway driving costs me $0.055 per mile ($2.20 / 40 = $0.055). On a purely cost basis, HV mode is the least cost efficient mode for driving. I realize there are a number of other factors that might come into play when computing cost, but I feel that these numbers accurately reflect the relationship between the cost of driving in the various modes. EV mode is the lowest cost, HV mode in city driving is higher. HV mode on the highway is the highest cost of all the modes for a Clarity. So this begs the question; "Why force the car into HV mode, its most costly mode, when driving on the highway if you have battery charge left?" For me, I never select HV mode. I drive all of my driving in EV mode until the battery depletes down to a level where the car decides to switch to HV mode on it's own. If I am driving further than the battery charge will get me, I want to arrive at my next charging location, usually home, with a fully depleted battery, maximizing those miles that I can at the lowest cost per mile.
Bear in mind, we’re only about 2 weeks into Clarity ownership, but here’s where we are now... Of course, local drives <40 miles we just do in ECON EV mode. On longer trips, we’ve been starting out in ECON EV mode until the battery drops to about 50%, then switching to ECON HV mode. Our trips often involve the foothills of the Appalachians, so we want to be sure to have plenty of battery reserve. Then about 20 miles from home, we switch back to ECON EV mode. The goal is to coast into our driveway as the last usable electron flows out of the battery. Or close to it. But of course we’re still learning, and this is all subject to change going forward.
There are several errors in your thinking, your numbers do not reflect the cost relationship correctly. The main one is your assumption that the EV range is the same in city or highway driving. My averages in current weather conditions are about 50 miles in town and 35 on the highway. You should calculate actual numbers for YOUR highway versus city driving conditions, both in HV and EV modes, if you want a real comparison Also, as other topics in this forum have discussed, if you have to go up a significant hill you may not make it at a reasonable speed if you've depleted the battery down to 2 bars. If all your driving is near flat this does not apply. The electric resistance heating used in EV mode also enters into this, it cuts EV range dramatically, and I think when it gets really cold I might drive in HV mode all the time unless I feel like tolerating no heat. This is also influenced by my high local electric cost almost $.18.
Actually, the salesman is correct in this case. The manufacturer recommends 91 which does not mean it requires 91. You can use 87 or 89 if your manual says so. If the manual requires 91, you have to use 91. So you have to pay attention to what Acura recommends or requires.
Maybe I am seeing what I want to see after reading this forum ... but my driving experience is more pleasant when the battery is not depleted. With the current low cost of gasoline, my cost per mile is actually lower burning gasoline, but the driving experience (for me) is so much more pleasant on EV or at least with some battery charge. I use HV on trips longer than EV range and switch to it before the car forces me to do so. I aim for coasting into the driveway as the battery goes flat but I'd much rather have some battery charge left over than have to drive with nothing in the battery.
So I found the gear icon today but also found why I hadn't noticed it before. 90% of my highway driving lately is on Connecticut Route 9, and it is all up and down hills to the point that maybe 1 mile out of 30 showed the gear icon. When you're going uphill engaging the gear doesn't give enough power/revs to get you up the hill so it all goes thru the generator, and downhill the engine goes off. I also today drove Interstate 95 and that is flat enough that the gear icon was on more than half the time.
You've hit on one of the more perplexing aspects of the Clarity PHEV. Only when the clutch is engaged (Engine Drive mode) is Honda's claim of 212 hp available (see Engine Drive mode illustration below--see illustration of all modes here). If that's so, why does the car have to switch to the 181-hp EV Drive mode when you need max power? The answer has to be the gas-saving tall gearing used for Engine Drive mode.
Perhaps there are, but you're the only one taking the time and trouble to explain things here. Thank you very much for your valuable contributions to this forum! It's much appreciated.
I always try to avoid arguments on forums, but I disagree--I'm not the only one. There are many very technical people on this forum--especially those with knowledge about battery chemistry and performance--who have taught me many things about this great car.
Perhaps I should have been more clear: Of those who have made a living as a technical writer, you are (so far as I know) the only one who has, upon occasion, taken the time to write clear and detailed explanations on complex subjects for this forum; explanations which communicate well enough that a layman can understand them clearly. I have been impressed enough with some of your posts that your ability in this regard stuck in my mind. I have occasionally been complimented on my ability to explain things clearly, but compared to you I'm just a rank amateur! Also, I'm pretty sure this isn't the first time I've complimented you on your ability. So take the compliment and stop arguing, sir.
That's my guess too. With the tall gearing the engine is likely way below its hp peak at normal highway speeds. I would offer to try cruising route 9 at 100 mph and see if it stays in engine drive mode more, my guess is it would, but that road is always crawling with police . Insightman I appreciate your efforts and knowledge too! Thanks!
Thanks. Fortunately, when I'm wrong, there are experts on this forum who can set me straight. I'm certainly no expert, just an interpreter. Thanks to Honda, there's a lot to interpret with the Clarity PHEV!
