New Honda CR-V Hybrid Powertrain?

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Agzand

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I was reading about the new CR-V Hybrid (4th generation hybrid powertrain) and I noticed that it mentions a 2 stage lock-up. I assume this means the direct drive mode (when engine drives the wheels) uses a two speed transmission or two different ratios. Details are not available yet, but I think this powertrain will solve the angry bees issue of the current hybrid powertrain.

I hope Honda will use this powertrain in another PHEV soon.
 
Agzand said:
Details are not available yet, but I think this powertrain will solve the angry bees issue of the current hybrid powertrain
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Let's say your conjecture is correct, and this is a dual ratio direct drive setup. Why would this solve the bees? Fundamentally, when the battery is unavailable to assist, the meager 1.5 liter engine is struggling to maintain speed under stressing conditions like sustained grades. The basic problem is that the ICE needs to max out to do this. This will happen whether you are locked into a different gear ratio, or struggling to produce enough kilowatts to drive the traction motor. The direct drive will presumably have to 'downshift' and it will likely need to rev up just as many bees as it does now. The only difference is perhaps a slight loss converting from mechanical to electrical to mechanical again.

I think the fundamental problem that requires the bees is the small engine. A larger engine would be required to solve this whether you have a 2nd direct gear or not.
 
MrFixit said:
Let's say your conjecture is correct, and this is a dual ratio direct drive setup. Why would this solve the bees? Fundamentally, when the battery is unavailable to assist, the meager 1.5 liter engine is struggling to maintain speed under stressing conditions like sustained grades. The basic problem is that the ICE needs to max out to do this. This will happen whether you are locked into a different gear ratio, or struggling to produce enough kilowatts to drive the traction motor. The direct drive will presumably have to 'downshift' and it will likely need to rev up just as many bees as it does now. The only difference is perhaps a slight loss converting from mechanical to electrical to mechanical again.

I think the fundamental problem that requires the bees is the small engine. A larger engine would be required to solve this whether you have a 2nd direct gear or not.
Click to expand...

Based on my experience the bees happen when speed is lower than what is needed to engage the direct drive. At higher speeds the engine was working hard, but it was not doing crazy RPMs (you cannot have angry bees in direct drive unless you are doing 100 mph or so). Having a lower ratio will allow the engine to engage at lower speeds of 25-45 mph that you encounter at steep upgrades.
 
MrFixit said:
Let's say your conjecture is correct, and this is a dual ratio direct drive setup. Why would this solve the bees? Fundamentally, when the battery is unavailable to assist, the meager 1.5 liter engine is struggling to maintain speed under stressing conditions like sustained grades. The basic problem is that the ICE needs to max out to do this. This will happen whether you are locked into a different gear ratio, or struggling to produce enough kilowatts to drive the traction motor. The direct drive will presumably have to 'downshift' and it will likely need to rev up just as many bees as it does now. The only difference is perhaps a slight loss converting from mechanical to electrical to mechanical again.

I think the fundamental problem that requires the bees is the small engine. A larger engine would be required to solve this whether you have a 2nd direct gear or not.
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I agree. The Accord Hybrid, which is a significantly lighter vehicle, has a bigger 2.0 litre engine because it does not have as big of a battery as the Clarity. Thus, when the Clarity battery is depleted, the 1.5 litre engine is vastly underpowered for going uphills or for passing. Indeed, Toyota even thinks a 2.0 litre engine is too underpowered. Most of Toyota's hybrids have 2.5 litre engines for vehicles lighter than the Clarity. Thus, when you deplete the Clarity's traction battery, you are then driving a terribly underpowered vehicle. That's why I never allow it to go below 50% before going into HV mode. It makes no sense to put yourself in a situation where your two ton vehicle has a maximum 100 - 120 hp available. It can even be unsafe.
 
The underpowered engine is understandable. It is a heavy car with a small engine. If you are an older driver particularly from other parts of the world, you remember that at one point most cars were underpowered. They could get out of their own way however, using correct gearing.

The issue that I had a few times, however, is not directly related to that. It is more of a gearing issue. Being able to engage the engine at lower speeds definitely makes a difference.
 
For me living on the East Coast and never driving this car West of Ohio, I've never experienced anything beyond what I'd compare to a 4 cylinder motor revving up a hill. With that said we don't have steep/long inclines and I usually keep some EV reserve until I'm closer to my destination. Agree with the comment above, we've gotten used to nearly every car having a v6 with +200hp.

As a kid I lived on a hill and I remember my parents would sometimes turn off the AC for a little more power in our 4cyl Accord ;)
 
This article has more information on new Honda hybrid setup:

https://www.caranddriver.com/reviews/a41623655/2023-honda-cr-v-sport-touring-hybrid-by-the-numbers/

"But the engine isn't just a generator, and substantial changes made this year have given it more time to shine. For the first time, they also allow the hybrid a tow rating—just 1000 pounds, but it's something. This is thanks to the internal-combustion engine, electric motor, and generator no longer sharing a common axis. They've been moved off-axis from one another, allowing the engine to be clutched into the mix to directly drive the wheels in two ratios, not just one, as was the case last year. Add a third ratio for electric-motor drive, and you have what amounts to a three-speed automatic like you've never seen.

The main scenario in which the engine comes online is steady-state cruising, when the Atkinson-cycle engine's efficiency as a direct-propulsion unit is better than if it were relegated to generator duties. Low-gear lockups can occur between 12 and 50 mph, while high gear may engage between 50 and 68 mph. During freeway cruising, the engine is probably doing the work on its own, with rpm only gently rising or falling in relation to speed."

The main improvement is that the direct drive mode now accommodates two ratios, instead of a single ratio before. This should be helpful in "Angry Bees" situations.
 
It will depend on the amount of horsepower and torque that can be delivered in EDM, even with 2 speeds. The Clarity disengages EDM almost immediately when anything more than light acceleration is called for.

Of course, we’re comparing a mild hybrid with a 1.1KWh battery to a PHEV with a 17kWh battery. This makes the mild hybrid much more dependent on the ICE. Honda engineers, being Honda engineers, may decide that the hybrid drivetrain is unsuitable or unnecessary in a PHEV.
 
Agzand said:
The main improvement is that the direct drive mode now accommodates two ratios, instead of a single ratio before. This should be helpful in "Angry Bees" situations.
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I'm surprised we didn't read a name for this new motor-off-driveshaft-axis hybrid configuration.

The Japanese Kurama Motor Vehicle News reported on the Chinese CR-V Sport Hybrid e+ (a PHEV) employs Honda’s twin-motor hybrid system “e:HEV” (formerly known as i-MMD), so it doesn't sound like it's as advanced as this unnamed off-axis hybrid configuration.

The Kurama article says the Chinese CR-V PHEV has an electric range of 53 miles (surely not an EPA 53 miles). This Inf.news article says the Chinese CR-V PHEV has a 16.3 kWh battery.

I'm once again amused that the motor in Honda's next-gen CR-V Hybrid is rated at their hybrid-standard 181-HP and the total output is their mysterious hybrid-standard 212 HP, regardless of the engine's HP.
 
Agzand said:
Based on my experience the bees happen when speed is lower than what is needed to engage the direct drive. At higher speeds the engine was working hard, but it was not doing crazy RPMs (you cannot have angry bees in direct drive unless you are doing 100 mph or so). Having a lower ratio will allow the engine to engage at lower speeds of 25-45 mph that you encounter at steep upgrades.
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I had my first experience with the bees this week, after about 4 months and 9K miles of ownership/operations. It occurred at 70-75 MPH with the ICE turning 5,100+ rpm and sucking fuel at a rate above 6 gph. I think your premise may be in err. I should add that this occurred on more or less level terrain after steady 70-75 mph cruise in sport mode that gradually depleted the HV battery.
 
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AHolbro1 said:
I had my first experience with the bees this week, after about 4 months and 9K miles of ownership/operations. It occurred at 70-75 MPH with the ICE turning 5,100+ rpm and sucking fuel at a rate above 6 gph. I think your premise may be in err. I should add that this occurred on more or less level terrain after steady 70-75 mph cruise in sport mode that gradually depleted the HV battery.
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That is certainly possible if your battery is depleted. The engine needs to generate as much electricity as it can to move the car at 75 mph. If you slow down a bit to allow the direct drive mode to engage, it should go away. The angry bees situation that I am talking about happens with a relatively full battery when the car is in hold state of charge mode.

Anyway, it looks like Honda has acknowledged this problem and the new two-speed setup allows the engine to engage directly at lower speeds needed for steep inclines.
 
I'm admittedly new to the car, only 4 months and 9k+ miles in, but I drive it every weekday 51 miles in HV mode, battery hanging in the 89%-92% SOC, mostly, but not all, freeway speeds, 55-75 mph, and have yet to experience angry bees in that regime. Up until about 3 weeks ago, I'd do the return trip of 51 miles in normal mode until SOC had decreased to about 20%, then engage HV mode until EV range was equal to remaining trip distance + 2 mi, then return to default mode. Since then, I've just been launching from work in Sport, battery hits zero range at about 11% SOC about 17 miles from destination and falls to 5%-7% after ICE activates at about 10% SOC, it is thereafter maintained 8%-10% SOC for the remainder of the trip. This methodology delivered my first angry bees experience and although I didn't take specific note, my working postulate is that occurrence was the first time that initial activation of the ICE was concurrent to battery depletion, as I usually trigger it much earlier in the evolution during a challenging merge situation. In that case, SOC dipped to 1%, ICE hit 5k rpm and fuel rate topped 6 gph. I left it in cruise control mode, didn't change anything and the event lasted maybe 30 sec, or so, at which point HV battery was above 5% and things returned to normal.
 
AHolbro1 said:
I'm admittedly new to the car, only 4 months and 9k+ miles in, but I drive it every weekday 51 miles in HV mode, battery hanging in the 89%-92% SOC, mostly, but not all, freeway speeds, 55-75 mph, and have yet to experience angry bees in that regime. Up until about 3 weeks ago, I'd do the return trip of 51 miles in normal mode until SOC had decreased to about 20%, then engage HV mode until EV range was equal to remaining trip distance + 2 mi, then return to default mode. Since then, I've just been launching from work in Sport, battery hits zero range at about 11% SOC about 17 miles from destination and falls to 5%-7% after ICE activates at about 10% SOC, it is thereafter maintained 8%-10% SOC for the remainder of the trip. This methodology delivered my first angry bees experience and although I didn't take specific note, my working postulate is that occurrence was the first time that initial activation of the ICE was concurrent to battery depletion, as I usually trigger it much earlier in the evolution during a challenging merge situation. In that case, SOC dipped to 1%, ICE hit 5k rpm and fuel rate topped 6 gph. I left it in cruise control mode, didn't change anything and the event lasted maybe 30 sec, or so, at which point HV battery was above 5% and things returned to normal.
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It's great to have another scientifically-minded Clarity driver like you in this forum!
 
In the Clarity, high engine RPM’s occur when power demand exceeds that which can be delivered from the traction battery. This can occur at any battery SOC and at any speed. Try it for yourself and see.

FWIW: 100hp converts to 75kW. A 75kW generator at full load will consume approximately 6.1gph. This is essentially what the engine in the Clarity is doing at 5100rpm.

Finally, automotive journalists frequently make inaccurate statements when reviewing new vehicles.
 
Agzand said:
Looks like the new Accord hybrid will have the same powertrain:

https://www.caranddriver.com/news/a41912905/2023-honda-accord-revealed/
Click to expand...

Car and Driver writes:
Combined power output is 204 horsepower and 247 pound-feet of torque, and Honda claims it will feel more responsive than the previous system.

The 2022 Accord Hybrid offers 212 hp @ 6,200 RPM and 129 lb-ft @ 3,500 RPM. I thought it was a Honda rule to claim every non-Insight hybrid they made (including the new CR-V hybrid), regardless of engine and motor, produced 212 hp. I'm shocked, shocked Honda says the 2023 Accord Hybrid will put out only 204 hp. Perhaps there are unrevealed differences between the 2023 CR-V and Accord hybrid powertrains.

However, the torque boost from 129 lb-ft to 247 lb-ft is very impressive. That's even more than the 232 lb-ft our mighty Claritys churn out.
 
Some random thoughts that came to me while reading this thread:

The name of the hybrid drive system is iMMD. The new CR-V uses the fourth generation of iMMD. (1st=2014 Accord PHEV, 2nd=not mass produced, 3rd=2017+ hybrids). The line of cars that use it is called e:HEV.

In Engine Drive, the ICE's rpm is 37*MPH in the Accord. At least similar, and probably the same in the Clarity. But I'm not sure. It is used only in low-power situations, when the car needs less than the power of the engine operating at its most efficient. That's 34 HP in the Accord, and probably about 25 HP for the Clarity.

High power requires Hybrid Drive. "Angry Bees" happens at when high power requires high rpm. That is, when running the ICE at that power level is far short of the needs of the car. The sound is due to high rpm, close to 6000 rpm.

Motors do not produce power, they convert electrical power to mechanical power. Their role in HEVs and BEVs is closer to the role of a conventional car's the transmission (which, at most speeds, converts high-rpm mechanical power to low-rpm mechanical power) than the engine.

The energy sources in an iMMD system are gasoline and the battery. Power is extracted from them by the ICE and Power Control Unit (PCU), respectively. This is what a car's power rating should reflect. Despite what the marketing department puts on spec sheets ("Total system horsepower [is] measured by the peak, concurrent output of the two electric motors and gasoline engine"), there is nothing "concurrent" about the output of those three devices when the iMMD runs in Hybrid Drive. "Concurrent" means "operating in parallel," and those devices operate in series. Adding them when a Clarity is running at max power would come to almost 400 HP, and be meaningless since the motor-generators are just converting the power of another.

It is not "non-Insight" hybrids that are (were) rated at 212 HP combined. It was those that used the 181 HP traction motor. Because 181/0.85=212. The Insight used a 129 HP motor, and has a 151 HP "combined" rating because 129/0.85=151. The City/Jazz hybrid also uses that formula, but I don't have its specs handy.

The reason for this is that there is a rule of thumb, that the max power at the wheels of a conventional car is 85% of the power the ICE can produce. Yes, I know this is inaccurate - here is a site that discusses it. All I'm saying is that it exists, and that Honda quite clear;ly uses this rule-of-thumb to back-estimate the power needed by the traction motor. The generator+battery are probably more capable, but this is saying no more will ever be used.

That was when there wasn't a standard for HEVs. Now apparently there is. The new CR-V is rated at only 204 HP, but that is actually a slight increase in power, since the 212 HP Accord and CR-V would have been rated at 201 HP with this standard. I have no idea what the Clarity would get, but there is no longer a reason to expect it is the same.

Finally, I have seen mixed reports about the two-speed lock-up in the new CR-V. Some say it is for towing, and some say it is for lower speeds. I think I saw somewhere that it doubles the gear ratio, but I also don't have that handy. My point is that I don't know for sure if the Accord will get it.
 
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