petteyg359
Well-Known Member
HV charge consumes is exactly the same efficiency as HV, it just shunts range to the battery. If you're not counting the miles gained in EV range into the mpg, you need to.
Its Not GOM its WOM
- Thread starter David Towle
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Eva Farkas
New Member
I am most certainly including the "miles" shunted to the EV side, but it is NEVER one for one. I don't lose 1 km (I'm in Canada, so we're on the metric system) in HV range and gain 1 km in EV range. It is ALWAYS more of a loss on the HV side than the gain on the EV side.
For example:
Before HV Charging, I might have 18 km EV range, 386 km HV range = Total range is 404 km
After HV Charging, I might get 26 km EV range, 372 km HV range = Total range is 398 km.
During this time, I may have driven 20 km, so in effect, my range was actually more like 398 km + 20 km = 424 km, but in monitoring my real time fuel efficiency (using the power info in the Clarity's interface), I see my consumption during that "trip" was more like 9 L/100 km, whereas my usual HV (non-charging) mode consumption (including using cabin heat/AC, etc.) is about 5.2 L/100 km.
HV Charge definitely does not consume the exact same efficiency as HV. In HV (without Charging), if I reduce my speed or pressure on the pedal, I will coast or be able to reduce my power output enough to fall in the EV range (blue on the power meter on the dash). During this time, the ICE is not running, and there is no gas consumption. I find I recapture quite a bit of additional EV range when driving in HV mode. Whereas my car never displays the "blue" range, regardless of what I am doing, in HV Charge mode. The ICE is running all the time I am in HV Charge, whether I am standing still (parked, or stopped at a red light), or driving.
petteyg359
Well-Known Member
Well duh, that's kind of the point.
If it turned off the engine while stopped how do you expect it to charge? And yes, the efficiency is the same. The gas generator generates the same power, and the direct gear engages the same way.
The only difference is that it stays on in charge mode. Sure, the gas generator is infinitely less efficient than plugging in at home and charging from solar panels, but it is the same gas generator running the same way whether HV or HV Charge.
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Honda specifically recommends in the manual, against using HV Charge in city driving or stop and go traffic. This is most likely the reason you are experiencing inefficient charging in that mode. If you have an opportunity where you can maintain a sustained high speed of say, 75-80kph or better, for 15 or more minutes, that would be a more appropriate time to utilize HV Charge mode.
Eva Farkas
New Member
Excuse me?
My response was pointing out that the efficiency in HV Charge cannot be the same as in HV mode, as they don't operate the same way. This is a direct challenge to to your statement "HV charge consumes is exactly the same efficiency as HV".
Of course the ICE has to keep running to charge. Yes, that is the point of the HV Charge option.
Furthermore, I wanted to make sure people understand that using HV Charge mode DOESN'T just shift range from HV to EV in the straightforward manner you're suggesting. There is definitely a "hit" to your efficiency if you chose to charge this way, rather than plugging in. You will use a lot more gas than you expected to, and will be largely negating the efficiency potential of this vehicle.
David Towle
Well-Known Member
I am in the process of a few tankfuls in just HV, to get a direct comparison of both range estimates and mpg.
petteyg359
Well-Known Member
You're arguing that, based on HV mode, the energy required to move the car and/or the power generation characteristics of the gas engine differ significantly.
Like Eva Farkas I was losing some mpg efficiency with HV Charge, but Landshark has hit that nail in a headly fashion on how to reduce that inefficiency.
David Towle
Well-Known Member
I've got my first comparison point on my Sarasota Florida gas use and I think its interesting. The last 5 tanks I was using exclusively the alternating EV/HV Charge system for my around town driving, Doing this the WOM was wildly inaccurate but I averaged 50-54 real mpg. This last tank I switched to exclusively HV with EV miles at zero so I didn't have to switch modes at all. The WOM was now pretty accurate at 309 miles when I filled up, but my mpg dropped slightly to 49. Not a big difference but seems significant. I am now running another tank exclusively in HV before I go back to the EV/HV Charge system, to see if its repeatable.
I think what happens here is there are 2 competing efficiency improvements. In HV you have gear mode, but I think at the slow speeds I travel here (40-55 mph) its not as big an effect as it is on the highway. With the EV/HV Charge system the engine restarts are cut by at least 90% so that has to be its own efficiency improvement. And the operational advantage of EV/HV Charge is large, in EV of course there's no engine noise, and in HV Charge the engine noise is much steadier and therefore less noticeable than in HV. I would guess NOx and CO emissions are much larger in HV with all the engine starts and stops. I'll report what i find on the next HV only tank. Note that here no matter where I go the driving conditions here are very consistent, no curves and no hills, drive about 1-2 miles then wait 2 minutes for a light.
I've consistently using AC about 10% of the total time, highway about 5%, All mpg figure are based exclusively on odometer versus gallons pumped. Sarasota is very straight roads, insignificant hills. I have a limited time frame to run these tests, when My house is complete I'll be running mainly electric power like most everyone else here.
Comments and questions appreciated.
I think what happens here is there are 2 competing efficiency improvements. In HV you have gear mode, but I think at the slow speeds I travel here (40-55 mph) its not as big an effect as it is on the highway. With the EV/HV Charge system the engine restarts are cut by at least 90% so that has to be its own efficiency improvement. And the operational advantage of EV/HV Charge is large, in EV of course there's no engine noise, and in HV Charge the engine noise is much steadier and therefore less noticeable than in HV. I would guess NOx and CO emissions are much larger in HV with all the engine starts and stops. I'll report what i find on the next HV only tank. Note that here no matter where I go the driving conditions here are very consistent, no curves and no hills, drive about 1-2 miles then wait 2 minutes for a light.
I've consistently using AC about 10% of the total time, highway about 5%, All mpg figure are based exclusively on odometer versus gallons pumped. Sarasota is very straight roads, insignificant hills. I have a limited time frame to run these tests, when My house is complete I'll be running mainly electric power like most everyone else here.
Comments and questions appreciated.
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