PHEVs to Rule Trucks?

[NorCalPete]

Motor Trend published an article discussing the advantages and disadvantages of EREVs -- nothing earth-shattering, but it does provide a decent overview of EREVs for anyone unfamiliar with them. Naturally, the Ramcharger got a mention. They also identified the Chevy Volt as a close cousin to EREVs but, as usual, no mention was made of the Honda Clarity.

 

[Landshark]

The differences are often subtle and frequently go unrecognized or misunderstood. A number of my otherwise intelligent associates were under the impression that the original Prius needed to be plugged in. One commented that he wouldn’t buy a Clarity because he needed a gas car.

That said, the term Extended Range Electric Vehicle is a misnomer. Any vehicle that is burning gasoline or diesel to generate electricity to charge batteries or send that electricity directly, more or less, to a motor, is no longer operating as an Electric Vehicle, Extended Range or otherwise, simply because there isn’t a direct connection between the engine and wheels. It is a plug-hybrid.

 

[ENirogus]

The differences are often subtle and frequently go unrecognized or misunderstood. A number of my otherwise intelligent associates were under the impression that the original Prius needed to be plugged in. One commented that he wouldn’t buy a Clarity because he needed a gas car.

That said, the term Extended Range Electric Vehicle is a misnomer. Any vehicle that is burning gasoline or diesel to generate electricity to charge batteries or send that electricity directly, more or less, to a motor, is no longer operating as an Electric Vehicle, Extended Range or otherwise, simply because there isn’t a direct connection between the engine and wheels. It is a plug-hybrid.

I am with you, but i do see a need for a different classification for vehicles that really don't lend themselves to use as primarily a gasoline vehicle. Now the current crop of PHEVs may not fit that bill, but if we have a non know nothing gov't in the future, a classification with large battery and small fuel tank ought to be in the same conversation as pure electric vehicles. I see a lot of use for this category in the next 10 years, and longer for trucks.

 

[insightman]

Motor Trend published an article discussing the advantages and disadvantages of EREVs

That Motor Trend article claims:
EREVs also have the potential to be more efficient than plug-in hybrids. Because that engine only charges the battery, it can be optimized for running in a narrow rpm range. It doesn't need to provide good throttle response or drivability, and parasitic losses from the transmission are minimized. The net result? You get more energy out of a given gallon of gasoline, which is better for both the environment and your wallet.

This setup also removes a lot of mechanical complexity from the equation. Traditional automotive hybrid systems often rely on complex transmissions with planetary gears to manage the hand-off of power between the motor(s) and engine. In an EREV, the power driving the car only ever comes from the electric motors.

It wasn't just on a whim that Honda added the mechanical complexity (and added expense and weight) of a clutch and gears to occassionally connect the engine to the drive wheels. The Clarity's Engine Drive Mode certainly isn't in any way an attempt to "provide good throttle response or drivability" as the Motor Trend article asserts.

Contrary to MT's claims, I believe increased efficiency is the only explanation why Honda (and Chevy) added parallel-hybrid capability to their plug-in hybrids rather than making them strictly serial hybrids.

Also, some drivers complain about the Clarity's engine running at speeds that don't vary according to the road speed. In a recent press release about the Honda S+ Shift next-gen e:HEV technology, Honda is addressing drivers' dissatisfaction with this disparity:

The newly developed Honda S+ Shift is a new function designed to pursue the “joy of driving” that further accentuates the sense of oneness between the driver and the vehicle, while fully leveraging the characteristics of the e:HEV system. The further advancement was made to the Linear Shift Control synchronizing vehicle speed with engine sound

It would seem an EREV's battery-charging ICE "running in a narrow rpm range" would run counter to the experience Honda believes drivers desire. Many Clarity drivers would agree--even if reports are true that the Ramcharger's 3.6L Pentastar V6 engine will run at a pokey 2,000 rpm when doing its thing.

 

[David Towle]

That Motor Trend article claims:
EREVs also have the potential to be more efficient than plug-in hybrids. Because that engine only charges the battery, it can be optimized for running in a narrow rpm range. It doesn't need to provide good throttle response or drivability, and parasitic losses from the transmission are minimized. The net result? You get more energy out of a given gallon of gasoline, which is better for both the environment and your wallet.

They may have the potential to be more efficient but I don't think its been realized. In every test I've seen comparing Hondas ( which are more like EREVs without the large battery) versus Toyotas (which integrate the electric and ICE power sources) the Toyota always gets substantially better gas mpg. Why I don't know.

 

[Landshark]

Honda claims that, under certain conditions, the Clarity is more fuel efficient when the engine drives the wheels directly through a transmission, aka: as a conventional ICE vehicle.

Motor Trend, and/or Stellantis, claim that the Ramcharger, or a similar Plug-in Hybrid, is more fuel efficient than a conventional ICE vehicle because the engine generates electricity, which charges a battery, which sends current to the motor(s). Of course, the Ramcharger lacks the ability to drive the wheels directly via the ICE, so what else would we expect to hear from the manufacturer about fuel efficiency?

Most likely, Honda is correct in that sometimes it is more efficient to operate as an electric vehicle and sometimes it is more efficient to operate as a conventional ICE vehicle, which is why they manufactured a vehicle that can do both.

A Series Plug-in Hybrid can’t do both, even if we call it an Extended Range Electric Vehicle.

 

[NorCalPete]

...even if reports are true that the Ramcharger's 3.6L Pentastar V6 engine will run at a pokey 2,000 rpm when doing its thing.

Ram reportedly will be implementing it's version of the "joy of driving" approach for the Ramcharger (as discussed in post #60). I'll be curious to see how both companies implement it and the overall impact on efficiency, which I assume will be less than running the engines at their optimum rpm.

 

[Landshark]

even if reports are true that the Ramcharger's 3.6L Pentastar V6 engine will run at a pokey 2,000 rpm when doing its thing.

Where have you seen these reports? Stellantis indicated that the engine would provide “intuitive” feedback. Presumably under acceleration, it would simulate an automatic transmission shifting through gears. In all probability, when lower power demand is called for, the engine would run at a steady rpm while charging the battery. I just haven’t seen any articles that mention 2000 rpm specifically.

 

[insightman]

Where have you seen these reports? Stellantis indicated that the engine would provide “intuitive” feedback. Presumably under acceleration, it would simulate an automatic transmission shifting through gears. In all probability, when lower power demand is called for, the engine would run at a steady rpm while charging the battery. I just haven’t seen any articles that mention 2000 rpm specifically.

I should have written the 2,000 RPM number I saw was speculation on Reddit. If my search for actual specs from Stellantis had been successful, I would have included a link.

As @NorCalPete pointed out, his post #60 is the most detailed information I've seen from a Stellantis employee regarding the Ram Ramcharger's anti-droning technology for this EREV's engine.

With the news that Ford is going to compete in the EREV arena, perhaps Stellantis will be more forthcoming with information in an effort to prove they're way ahead of Ford.

 

[Landshark]

I should have written the 2,000 RPM number I saw was speculation on Reddit. If my search for actual specs from Stellantis had been successful, I would have included a link.

With the news that Ford is going to compete in the EREV arena, perhaps Stellantis will be more forthcoming with information in an effort to prove they're way ahead of Ford

Thanks for clarifying that the reports are just forum speculation. What specs were you looking for? Something that that showed the engine rpm’s of the V-6? All information to date suggests that engine rpm’s will be variable based on charging needs and creating an intuitive feel for the driver. I’d interpret that to mean anything from idle to redline. Peak generator output could be achieved well below the engines maximum power rating which could allow the rpm’s and power output to be limited to align with generator output. Maybe they’ll limit rpm’s to 3500, or whatever speed coincides with max generator output. That would certainly allow the engine to rev up, then “shift” and rev up again when accelerating. Many newer trucks and SUV’s are equipped with 8-10 speed transmissions which makes the shifts almost imperceptible, unlike my 1999 GMC truck, so I’m not certain what sort of automatic transmission shifting experience Stellantis is attempting to create.

Stellantis is already ahead of Ford in the PHEV arena. The Jeep 4xe models are now in their 4th year of production and have been the top selling PHEV in America. The addition of the Ramcharger to their PHEV lineup, as a Series Plug-in Hybrid, puts them ahead of not just Ford, but every other auto manufacturer as well. They also have Harrison Ford promoting Jeeps. Ford didn’t see that coming.

 

[ENirogus]

I dunno, while my wife's old Nissan SUV, and a previous Subaru had that odd single speed CVT, so what?
Seriously, why do you car what the engine is doing, unless it is being annoying.
A true generator has one optimum speed. One could sound deaden such that you barely know the engine was running at whatever that speed is.
This is not a 73 Toyota thrashing wildly to create 12 horsepower

 

[TC1782]

Thanks for clarifying that the reports are just forum speculation. What specs were you looking for? Something that that showed the engine rpm’s of the V-6? All information to date suggests that engine rpm’s will be variable based on charging needs and creating an intuitive feel for the driver. I’d interpret that to mean anything from idle to redline. Peak generator output could be achieved well below the engines maximum power rating which could allow the rpm’s and power output to be limited to align with generator output. Maybe they’ll limit rpm’s to 3500, or whatever speed coincides with max generator output. That would certainly allow the engine to rev up, then “shift” and rev up again when accelerating. Many newer trucks and SUV’s are equipped with 8-10 speed transmissions which makes the shifts almost imperceptible, unlike my 1999 GMC truck, so I’m not certain what sort of automatic transmission shifting experience Stellantis is attempting to create.

Stellantis is already ahead of Ford in the PHEV arena. The Jeep 4xe models are now in their 4th year of production and have been the top selling PHEV in America. The addition of the Ramcharger to their PHEV lineup, as a Series Plug-in Hybrid, puts them ahead of not just Ford, but every other auto manufacturer as well. They also have Harrison Ford promoting Jeeps. Ford didn’t see that coming.

If it is a series hybrid, they will make the generator size up to the engines max power output. Limiting the engine to 3500RPM (presumably below where the engine makes max power) would make little sense. If the engine makes max power at 6000 RPM, they will limit the engine to 6100 RPM.

 

[ENirogus]

If it is a series hybrid, they will make the generator size up to the engines max power output. Limiting the engine to 3500RPM (presumably below where the engine makes max power) would make little sense. If the engine makes max power at 6000 RPM, they will limit the engine to 6100 RPM.

Well, remember that a series hybrid needs no power curve. One could design and engine [cams fuel delivery pistons] to deliver max power at a lower rpm, a single lower rpm. Less efficient in several ways. They only reason for the torque peak/horsepower peak spread we are used to seeing is fixed ratio transmissions
Wind up to a higher rpm, shift, still have adequate torque after the upshift
Think of Diesels, they shift at, what, 500 rpm spreads

 

[Landshark]

If it is a series hybrid, they will make the generator size up to the engines max power output. Limiting the engine to 3500RPM (presumably below where the engine makes max power) would make little sense.

It is a series hybrid with a 130kw generator and an engine rated between 211-224kw. It appears that Stellantis isn’t following your theory. Ninety percent of maximum torque is available at 1800rpm, so there isn’t much need to spin the engine up to 6000rpm in this application.

FWIW: Fixed speed generators run at 1800 or 3600 rpm’s, depending on whether they have an alternator with 4 poles or 2. A 20K generator will run all day at 3600 rpm even if the load is only 2K. That’s not a formula for efficiency.

More commonly we see inverter (or variable speed) generators that are capable of adjusting engine speed, and hence generator output, to meet changing power demands. A 20K inverter generator might run at 1000rpm to meet a 2K load, thereby reducing fuel consumption compared to an engine that always runs at 3600rpm.

A similar principle applies to the Ramcharger. While the current from the generator can supplement current from the battery to produce additional power from the motor, the generator’s primary function is to maintain the battery’s level of charge. The system is more advanced than a generator meeting immediate demands. It can allow the battery to be depleted somewhat and then restore that energy over time. Point being, the engine and generator output do not align as you’ve suggested.

 

[insightman]

It is a series hybrid with a 130kw generator and an engine rated between 211-224kw. It appears that Stellantis isn’t following your theory. Ninety percent of maximum torque is available at 1800rpm, so there isn’t much need to spin the engine up to 6000rpm in this application.

FWIW: Fixed speed generators run at 1800 or 3600 rpm’s, depending on whether they have an alternator with 4 poles or 2. A 20K generator will run all day at 3600 rpm even if the load is only 2K. That’s not a formula for efficiency.

More commonly we see inverter (or variable speed) generators that are capable of adjusting engine speed, and hence generator output, to meet changing power demands. A 20K inverter generator might run at 1000rpm to meet a 2K load, thereby reducing fuel consumption compared to an engine that always runs at 3600rpm.

A similar principle applies to the Ramcharger. While the current from the generator can supplement current from the battery to produce additional power from the motor, the generator’s primary function is to maintain the battery’s level of charge. The system is more advanced than a generator meeting immediate demands. It can allow the battery to be depleted somewhat and then restore that energy over time. Point being, the engine and generator output do not align as you’ve suggested.

The special logo for Stellantis' EREV (or in Stellantis-speak "electric pickup") and BEV (or in Stellantis-speak "REV" for "Revolution Electric Vehicle") vehicles was revealed more than a year ago. Hopefully, before 12/31/25, Stellantis will take an automotive journalist for a ride and we'll learn more about the Ramcharger than what Car and Driver has sussed out so far.

 

[leop]

One of the important things to consider when designing a series hybrid is the brake-specific fuel consumption (BSFC) of the internal combustion engine. This is a measure of power output per amount of fuel used. Of course the engine must be able to produce sufficient power to keep the battery charged on average but also the power needed, if there is a direct connect between the generator and traction motor, to supplement the maxumum power available from the battery. The usual design is to have the engine sized to operate at the maximum BSFC when producing the power needed maintain, on average, the battery charge. This maximum BSFC operating point is also usually not the maximum power operating point but usually an operating point at less rpm.

Honda appears to have done a very good job designing the PHEV Clarity to meet the above design needs, including the use of the engine-drive-mode.

LeoP

 

[Landshark]

Hopefully, before 12/31/25, Stellantis will take an automotive journalist for a ride and we'll learn more about the Ramcharger than what Car and Driver has sussed out so far.

As mentioned previously, production is scheduled to begin on 4/14/25 at the Sterling Heights factory. Dealer deliveries are expected in May. The 2025 MY production run will end on 6/6/25. Production for the 2026 MY will begin on 6/16/25.

 

[Landshark]

Apparently BSFC does not apply to the Ramcharger since it has been adorned as an Electric Vehicle.

 

[Landshark]

I'll be curious to see how both companies implement it and the overall impact on efficiency, which I assume will be less than running the engines at their optimum rpm.

How would we be able to determine the overall impact on efficiency without a sample vehicle that is engineered to have an engine that only runs at its optimum rpm?

Would it be worth the effort to try to calculate the difference in fuel consumption between an actual vehicle and a fantasy vehicle? Is anyone who might buy this truck going to have a meltdown because it could have achieved 20mpg, but only gets 19mpg?

 

[ENirogus]

One of the important things to consider when designing a series hybrid is the brake-specific fuel consumption (BSFC) of the internal combustion engine. This is a measure of power output per amount of fuel used. Of course the engine must be able to produce sufficient power to keep the battery charged on average but also the power needed, if there is a direct connect between the generator and traction motor, to supplement the maxumum power available from the battery. The usual design is to have the engine sized to operate at the maximum BSFC when producing the power needed maintain, on average, the battery charge. This maximum BSFC operating point is also usually not the maximum power operating point but usually an operating point at less rpm.

Honda appears to have done a very good job designing the PHEV Clarity to meet the above design needs, including the use of the engine-drive-mode.

LeoP

I don't believe this vehicle will have any connection between the ICE and the wheels, but I could be wrong
The engine currently specified is so much larger than required for engineering reasons, I don't think things like BSFC come into play. The engine is sized for NVH and marketing reasons, not technical reasons, but I suppose one could say that about most vehicles, since my Kia rarely uses its sub 7 second 0-60 and your 1970 average Caddy with a 500 rarely used that performance.
If people are really driving this truck primarily on gas, they are wasting their money.
Super super useful for long range and especially towing, and should out perform most pure ICE trucks in economy doing that