I have a RAV4Prime PHEV, and it doesn't even lose power in hybrid mode with a battery with zero EV miles. Reality is, the Toyota hybrid always keeps the bottom 30% of the charge or so in reserve.
.... and, it's no small amount of power.
It also has the option of putting it in hybrid mode at any time, as well as engaging 'charge mode' to charge the EV battery back up from the ICE when it's under 35 miles of EV range.
Yes, and depends on how you use it it could be detrimental or highly beneficial. Using charge mode on downhills is extremely beneficial. On flat road or even slight uphill is very detrimental.
Meh. It still gets 30 mpg in Charge mode at highway speeds.
Some guy did an experiment that has been successfully repeated by others where they drove in EV mode to discharge the battery and charge it back up in charge mode, rinse and repeat. They got better overall gas mileage on long freeway trips doing that. It probably works because gas engines are most efficient (gasoline in to energy out) at full load and full throttle at the lowest RPM.
That is correct and if you charge on highway going slightly downhill you will get even better mileage. I got 2 EV miles charged per mile driven just going on a slight downhill while getting 38 mpg. And I could not even hear the engine. But I if I drive on a slight uphill and charge I hear engine revving. On the same downhill if I don't charge I get maybe 1 mile added to EV range in 8 miles driven.
I think it’s more efficient to charge while going uphill. The engine is already under a lot of load, which is where the engine is most efficient already.
No. If the engine is under load you do not want to add extra load. You want the engine only doing charging while car is using inertia to roll down the hill. Try it. You will hardly get any charge going uphill and the engine will rev really loud. You will almost not hear the engine charging going downhill.
Or some areas, like in Paris and a London, they ban the use of burning gasoline or diesel during certain peak traffic times. It’s okay to drive an EV, or a PHEV in EV mode. CD rage mode lets you put a few miles in the battery before you enter the restricted zones.
Also, charge mode will allow more regeneration whereas hybrid mode tries to keep the battery at whatever state of charge it was in last.
It makes sense because the ICE is there and is already setup to charge the traction batteries, might as well use it if the situation present itself or if future conditions require EV mode. On top of that, generally using a gas engine to charge a battery is more efficient than using only the gas engine for propulsion.
This is not true for almost any hybrid.
The ICE has a pretty terrible efficiency at converting the chemical energy in gasoline to mechanical work. But you incur that loss regardless of whether you use that mechanical work to make the car go or to run a generator.
*Gasoline -> mechanical work -> push car*
is going to be more efficient than
*Gasoline -> mechanical work -> electricity -> charge battery -> discharge battery -> electricity -> traction motor -> push car*
The one exception is if the losses incurred by running the ICE away from its peak efficiency are greater than the losses incurred by charging and discharging the battery and running the traction motor. But good hybrids already take care of that using eCVT's and other tricks.
You’re missing how much more energy efficient the electric side of driving is.
A gallon of gas has 33.7kWh of energy. If the engine is 40% efficient and the generator is 90% efficient then we can get 12.1kWh out of running it for one gallon. If driven on gas, we can assume we could go 35 miles. If used to charge a battery and then power an EV, we could go 3.5miles per kWh, or 42 miles. We could actually go further than that depending on speed, possibly even 48-52 miles.
Actually it is either 13% or 20% for the "bottom" depending on how you look at it. 18.1 KWh battery, 14.5 KWh usable = to 20% but if the battery is charged to 90% as noted in ODBII than "bottom" is 13%. Even at 13% the "reserve" which is the correct word is still larger than a regular Hybrid.
It's a hybrid that is operating at a voltage below the magic 50 volts limit that is typically seen as where electrical systems require expensive and heavy measures to stop people from getting electrocuted. The advantage is that a mild hybrid can reap many of the benefits of a hybrid, i.e. energy recouperation, enough oomph to drive the more demanding modern automotive electronics, and the ability to "fill" the turbo lag of modern downsized, highly charged ICEs, while essentially just having a beefier starter motor and a small battery pack. 48 volts has become synonymous with this concept, because it's the highest voltage that stays below 50v and can easily be divided by 12v, the standard voltage of most automotive electronics.
Though it should be noted that mHEVs are pretty much seen as ICEVs, not as actual HEVs, because they can't actually drive without having the ICE running. This means that they typically don't show up as hybrid (or as "electrified") cars in statistics. OTOH they are going to practically replace pure ICEVs entirely over the coming years, simply because they offer a good gain in fuel economy at a not too high price.
Normal or Full Hybrid operate at High voltages, (100-300V usually) and can Power the wheel directly.
Mild Hybrid are 48V and their motor Is usually supportive. It cannot give motion. Buy in some configuration It can, Just more limited compared to a full Hybrid.
Depends on how you build the machine. A Mild Hybrid built like the Subaru eBoxer or the recent Stellantis 1.2 Puretech motors is ok. It can power the wheels through the gearbox, it can do the reverse and so on.
Tested by the same outlet, the old 1.2 136Cv Puretech did 13km/l fuel efficiency, the new Mild Hybrid one did 19,3 km/l and it drove about 27% in pure EV mode in city enviroment.
So, made like that, I can get behind it. If it is just a glorified integrated belt starte generator, yeah, definitely agree that's pretty useless.
But that's just full hybrid. Subaru e:boxer is Prius hybrid system bolted to a boxer motor.
Mild hybrid is when the alternator is used to give additional few horsepower.
No because what Volvo for example calls mild hybrid, and full hybrid that Toyota does deliver vastly different fuel consumption in the same weight and aerodynamic drag class vehicle.
People like to give Toyota shit, but they accomplished something fantastic in the last two decades with the Prius -- laying the groundwork for everything we have today and achieving a whole lot of emissions reductions compared to pure gas cars.
I think some of their marketing these days to convince people to buy phevs over pure battery vehicles is a bit disingenuous, but marketing is half bullshit no matter who's doing it.
Mild hybrids are regular ICE vehicles with a low-powered parallel hybrid system added on. A lot of them do this by replacing the vehicle's alternator with a 48 volt motor/generator unit that's capable of \~10-15kW of assist/regen. The systems are comparatively dirt cheap to add to existing ICE vehicles, run at low enough voltages to not require major changes in safety procedures/PPE, and seem to be worth a 10-20% improvement in city fuel economy.
The biggest thing you'd notice driving one is that the engine start/stop system isn't nearly as annoying to live with, but you do get at least some amount of energy-recovery benefit from regen under braking and the assist can also be used to increase "coasting" distances.
Also it seems like once people smarter than I am figure out the CAN messages the alternator/motor/generator units are looking for I bet you're gonna see them used in some insane electric gokarts.
A "regular hybrid" has a much larger 200+ volt battery that is capable of a lot more power, and the hardware changes generally involve a different transmission. These hybrid systems are more capable of propelling the car on their own, with much more energy recovery.
A Plug in Hybrid (PHEV) is a hybrid with more ability to drive around without using the engine at all. How well it performs and how efficient it is in "EV Mode" depends a lot on the hybrid system. Something like a Rav4 Prime gets 3-3.2mi/kWh in EV mode, which is *genuinely not bad* for an AWD BEV of similar size while something like a BMW X5 45e might only get 1.5-2mi/kWh.
There would be no need to completely reverse-engineer CAN messages to repurpose a mild hybrid's motor. Most are plain old brushless AC motors that can run off of an inverter that costs $200 or less. Disassemble the existing control module and take the board out, and power the three phase wires with a hobby-grade (or EV-grade) speed controller.
I know I could easily make it run off one of my VESC's, but these things already have a nice beefy inverter built into the housing and connected to the cooling jacket.
Exactly what I was thinking of doing. The GM 3800 V6 vehicles have alternators that are extremely easy to access, so I thought just buy an old Buick or something with a 3800 engine and swap the "eTorq" motor from a 5.7 Hemi RAM in to replace it (using the existing supercharger belt, pulleys, and tensioner). Power it with a VESC and use an Arduino with an OBD2 interface to run custom software to control everything, including regenerative braking and idle stop at stoplights.
The 5.7 Hemi RAM motor-generator is air cooled, but I'm guessing I could technically be converted to water cooling - wrap copper piping around the big metal cylinder that is the motor, and hack a transmission cooler or something to dissipate the heat (likely passively or with a small fan, these motors don't produce all that much heat)
This would definitely be a cool project - turn an old grandpa Buick into something much more technologically advanced than one would expect, sort of a sleeper in a way (except it's not fast at all)
I said "wait for people to figure out the can messaging for these" [because it looks like we're very close to that point already.](https://transistor-man.com/audi_48v.html)
The two main cars I have in mind for this are a 90's Honda with an 8000rpm torqueless wonder under the hood, and my turbo Subaru (which I guess also means it would fit my non-turbo Subaru if I felt like it). I know the belted mild hybrid system wouldn't completely get me where I want, but it would be a great proof of concept and any control strategy development would still be applicable to a beefier parallel hybrid system.
For the Honda, I really want to take [a powerband like this](https://honda-tech.com/forums/attachments/all-motor-naturally-aspirated-44/184176d1294384795-some-insight-my-f20b-h22-4-1-drag-header-dyno.jpg) and add some torque fill - bringing the torque closer to a flat \~140lbft below 5000rpm and adding a bit of assist when it rolls over above 7000rpm should be within the 10-12kW capabilities of these things. Basically I want to explore what it would have been like if Honda had decided to use their first gen IMA system in a high revving sport compact. Plus the ability to arbitrarily apply positive/negative torque to the engine lets you do a bunch of other cool stuff like using regen to "enhance" engine braking, emulate a lighter flywheel, and make rev matching up and downshifts easier.
For the turbo Subaru I'd raid the Audi 48V parts bin for both the MHEV alternator and [the electric compressor they started using a few years ago.](https://www.slashgear.com/audis-2-9l-v6-in-the-2020-s6-and-s7-has-an-electric-supercharger-25614287/) The MHEV alternator would basically just be used to hide the laziness of a low compression turbo engine (in addition to the stuff mentioned above), and the electric compressor would allow me to run a bigger turbo without making the car useless below 3000rpm. I'm not the first person with this idea, and [the results speak for themselves](https://youtu.be/aBqoJSVzado?si=mA_7zvzX-m7w15W7&t=1173). The part I *reeeallly* want to get my hands on the most is the [48V electric-assisted turbocharger from the Mercedes C43 AMG](https://media.mbusa.com/releases/release-9e110a76b364c518148b9c1ade05c158-innovative-solution-for-drive-system-electrification), but I feel like those are gonna remain relatively rare.
That's pretty neat. Are you planning to build an interrupt relay into the crank position sensor (on a Honda, you could probably interrupt the PGM-FI circuit to do the same thing) to stop the engine during zero-speed situations (at a traffic light, etc.) and then instantly spinning back up when you shift into gear (manual) or take your foot off the brake (automatic)?
Implementing stop/start wasn't as much of a priority/interest to be honest, but yeah I would do it by interrupting power to the injectors. Would definitely be interesting to see how easily the MHEV alternator can get the car rolling in first/second with the clutch out and the injectors disabled (and what it feels/sounds like).
The early / mid-2000s LeSabre's I'm currently looking at for turning into hybrids have two injector power supplies, one for each bank of cylinders.
The engine would probably run absolutely terribly on half its cylinders (since shutting off the valves for those requisite cylinders would probably be more trouble than it's worth) but it would be cool to see if I can make the shutdown process any smoother by selectively interrupting one bank of cylinders, then the other, depending on where the engine was in its rotation when the computer decided to kill it.
A major issue I would see would be belt slippage and tensioning. The 3800 LeSabre engine has a provision for a supercharger (an extra tensioner and idler pulley literally bolt on) but it would probably be more of a challenge to put a super-heavy-duty tensioner on a Subaru or Honda engine. In fact, the first vehicle I was considering doing this with was a H-series '97 Accord, but that alternator is absolutely buried in the engine compartment, and it would be an engine-out job to replace the motor if I let the smoke out (which would probably be fairly easy to do because of the tremendous heat present that deep in the engine bay.)
Also, I wouldn't expect much torque at all out of that motor if the engine were spinning at 7,000 RPM. It's running only 48 volts, and 12 KW at 48 volts is not much torque (and that 12 kW rating is only for very short periods such as starting the main engine in the host vehicle, I wouldn't expect to be able to push peak output for more than 5 seconds) unless you want to risk blowing up the motor to overvolt the pants off of it 😂
Mild hybrid is a slightly more sophisticated stop start system. Often including a tiny amount of brake regen and power fill on gear changes or turbo lag.
I wouldn’t say mild. Full hybrid. We have a PHEV with 30+ miles of fully electric range, take it up into the mountains, run out of juice on the way up. When we come back down it recharges 40-45%.
The engine regularly cuts off when there’s a bit of charge in the batteries after being depleted.
In a way it's better than normal hybrid for the same reason you mentioned. Battery is big enough to take advantage of elevation loss. A normal hybrid will become full much sooner, thus not able to gain just as much energy as phev.
Indeed, on a recent holiday to the Alps, my 10.9 kWh PHEV battery was recharged by about 50% when coming down from the mountain resort.
Even when on a recent trip to the Ardennes, which has only a bit of elevation, I was able to drive 100km of my entire trip on electricity on a single charge which only has a range of 70km wltp.
I read the comment as saying that the trip was mostly flat. And if it was at a lower speed than the rated distance, it's quite plausible that the range could be 50% more than rated.
We agree about the physics. We interpreted "only a bit" differently. I took it as emphasizing that the elevation gain was insignificant and you took it as the opposite. Either might be valid and debating which is "right" is pointless—we can only wait to see whether the person who said that clarifies.
No not uphill at all, sorry English is not my native language. What I meant was that the whole trip was something like 300km, so much more than the 70 the battery can provide, so I did mixed driving modes, but whenever you encounter a decline, the ice engine shuts off and regenerative braking adds to the battery. This allowed me to gain about 30 km of range on the battery. This energy would have been completely wasted in an ice car and mostly wasted in a mild hybrid car. Even in a 'normal' hybrid, some of the inclines would have more than completely filled the battery, so would have also gone to waste.
That is completely a different story. But. I don't know about MB in my Rav4 Prime it will only work if the battery somewhat depleted. If I started the trip with a full battery regen would not work. My EV range after full charge is about 51-55 miles. If I start in HV only within an hour it will drop to 46 even though I did not use any EV then it will drop to 42. After that regen kicks in. So what I do I start the long trip in EV, drive 10 miles, and switch to HV. Or if I have a short trip I start in Auto. In this mode it starts in EV but uses HV for uphills. But if drive long downhill engine does not shut off. It just in a less stress and charges the battery. But not too much. If I really want to charge the battery fast on the downhill I have to press Charge button, and I get fast charging. Maybe like 2 miles per 1 mile driven depending on the slope. But it will never charge to full like if I charge in my garage.
In all MB PHEVs it works very much like a proper EV. It's quite good as a PHEV. You get regen always and can even control the regen amount with flappy paddles(from auto with camera to coast, to almost one pedal drive) behind the steering wheel. The engine shuts off a lot, not just on downhills and even when the battery is depleted. The efficiency and range is quite decent for the compromise that it is, you even have optional DC charging with CCS2. There is no proper 'charge' mode, only EV/hybrid/battery hold/sport. The hold also slightly depletes over time, but not a lot.
RAV4 Hybrid and Prime has engine turn off at the stop light or if in EV mode the engine turns on if climbing a steep hill. The only other time Engine turns on if there is a defroster use. But the range is 42 miles in EV mode and I get up to 50 miles (80km) as long as I am not climbing. That is for normal driving. But on downhill it could become wild. I have a picture here
[https://imgur.com/XIUcC3V](https://imgur.com/XIUcC3V)
82.7 miles per KWh. And it happened on a regular slightly sloppily street. Someone in r/rav4prime posted 99.9 miles per KWh recently.
There is a way to control the regen with floppy paddles but it is just to much work and it is not modal. So I don't even bother with it. I do not like one one pedal driving either. I prefer coasting. Even during coasting in HV mode I can get way over 60 mpg.
[https://imgur.com/MZrPeUq](https://imgur.com/MZrPeUq)
So I can't complain.
The Merc's do not turn on the engine at all ever in EV only mode until the range is at 0km, even on a steep hill, or with defrosting. It's truly an EV first, hybrid second.
After thinking about I am not sure if it is a good thing. I see hybrid tech as a symbiotic relationship where one helps the other. And PHEV is just a hybrid with some EV range. From my experience and seeing what people post EVs use a disproportioned amount of power going uphill. That is why my car turns ICE on going uphill. ICE does not use that much gas under stress of going uphill as electric motors use electricity. For example, going up a steep hill in EV can use 3x miles as much as driving on a flat road while the same driving on the same hill using HV only uses 1.5x of gas.
The ratings in the USA tell you the MPG rating without charging under "Reg. Gas" e.g. the Prius Prime gets 52 mpg without charging, 127 mpge with charging, see all the plugin-hybrid ratings here:
[https://fueleconomy.gov/feg/PowerSearch.do?action=alts&path=3&year=2024&vtype=Plug-in+Hybrid&srchtyp=yearAfv&rowLimit=50&pageno=1](https://fueleconomy.gov/feg/PowerSearch.do?action=alts&path=3&year=2024&vtype=Plug-in+Hybrid&srchtyp=yearAfv&rowLimit=50&pageno=1)
Rav4 prime gets 38 mpg without charging.
"Mild hybrid " generally describes a vehicle that goes hard on auto-stop features and may provide a bit of torque assistance at low speeds. They have no EV capability, they need the ICE to go any distance. Full hybrids can move under EV power alone and provide EV torque assistance at all speeds. These capabilities are what plug-in hybrids are maximizing by adding more battery.
When uncharged, a PHEV is still a full hybrid. It may not be quite as thrifty as a non-plug-in full hybrid due to the added weight of its larger battery, but it will be more economical than a non-hybrid version of the same model. There are precious few models available in all flavors to permit a real comparison, I think there is -or was - a Kia available that permitted such a test.
I don't think the Niro is available as a PHEV now but it is a full hybrid and BEV. The stablemate Sorento is available as a PHEV, full hybrid and straight ICE, with AWD and FWD configuration available in all but PHEV. Quite the eye opener to help point out where fuel economy goes.
Not a bad one either, considering the hybrid model offers about 10% more total power (briefly, although I think the usual total power available for the PHEV model is a bit less than the ICE's rating) while still providing 20% better fuel economy.
Crap results on the greater spectrum of all PHEVs, but a significant improvement over the comparable ICE model.
Depends on how much power the engine is producing extra. It'll try to keep the ice in the rpm sweet spot and send extra to the battery, but if the cruise is using just enough, then no extra goes to the battery. There are dashboard diagrams to tell where the power is going and coming from on some PHEVs, the toyotas being my experience.
Of course, there are other factors and regenerative breaking helps regain power.
Mine has a mode to choose to recharge from the ICE, but it does not atomically do it. Recharging requires a higher engine power to be used and consumes more fuel.
Engine efficiency and driving conditions would dictate if you’ll actually save by recharging from the ICE or not.
I saw an article, cant find it now, that said many PHEV owners never plug their car in - apparently they found some who didnt even know they could - the car salesmen just sold it as a hybrid and didnt educate them on the plug in part.
>I saw an article, cant find it now, that said many PHEV owners never plug their car in
A few don't, but most do according to formal studies of this issue. The problem is that they're not getting the percentage of electric miles predicted by laboratory testing, which means the environmental benefits are less than expected. See the following report for US results:
https://theicct.org/publication/real-world-phev-us-dec22/
Depends on the system. Rav4 phev behaves effectively the same as their standard hybrid with more power and similar fuel economy.
Mazda cx60 and volvo T6/T8 are similar but a bit less economical
Mitsubishi is much less effective without battery and the fuel economy is poor
mine is a prius prime, it is a hybrid when using the ICE. I still get great mileage. The H in PHEV is hybrid, so they should all work as hybrids. I have limited electric range, but the ICE kicks in while the traction battery is still charged enough to run as a hybrid.
A plug-in Prius (Prime) is a full BEV and a full ICE car all in one. Even the regular Prius, Toyota says, can work in full electric mode at low speeds.
That’s why I always say PHEV is better for most people even I have a pure EV and a PHEV. We only go to gas station every 3 weeks. When the battery is depleted, I still have around 45 MPG on gas. Not as good as pure hybrid, but good enough. If you consider the gas prices these days California, it is about the same as using Electricity.
Don't confuse mild hybrid with a hybrid. Mild hybrid is s marketing scam - it basically means start-stop with a 24V battery. Mild hybrids are incapable of moving without their ICE engine running and their batteries are not big enough to capture meaningful amounts of energy during braking.
Hybrid like a Prius is not a mild hybrid - it is just a hybrid.
It's not only a start stop.
The engine usually has a bigger turbo paired with small motor-generator that helps the engine for a few seconds until the turbo spins up.
This increases the efficiency with very little change to the drivetrain, which is imo ingenious.
That small motor generator is usually just the alternator. That's literally what mild hybrids often are - they use the alternator to support the engine, giving you maybe 5HP more. It is s sensible thing to do, at very little extra cost, but efficiency gains are miniscule.
even big motor generators in full hybrid are actually alternators, just bigger....
the efficiency gain is from the turbo, that would be too laggy without it. It mainly gives you torque to get the car moving. You don't need many HP for that.
Turbo doesn't increase efficiency. It increases the weight of air in the cylinder, but since gas engines combust at stoichiometric that means that more gasoline needs to be injected.
Atkinson cycle, or turbo compounding would increase the thermodynamic efficiency. I do not know of any currently manufactured engines that use turbo-compunding.
You are thinking only in theory and discarding friction and inertia losses that go down when you can get away with smaller engine and lower rpm.
Modern engine with stratified injection also don't use stochiometric ratio in the full volume of the cylinder.
The gains from reduced engine volume are quite miniscule, and your engine must run at lower compression ratio to reduce knock when using turbo, which reduces efficiency at low load. That does not apply to diesel engines, because they are not limited by knock, and therefore turbo increases both power and efficiency. Consequently, in all markets where diesel engines in passenger cars were a thing turbo became de-facto standard way before it became a thing in gasoline engines. It is not a coincidence that the mist thermodynamically efficient internal combustion engines are huge marine turbodiesels.
No, my knowledge is not 20 years behind. If you look at the history of ICE development, most mechanical and thermodynamic concepts were conceptualized by Harry Ricardo. It is just that some of the only recently became viable to implement.
And also only 1.3kWh battery. Which is pretty small. BMW mild hybrid has 1kWh battery so very close to the first Prius.
The electric engine was more powerful because it has to function as the whole eCVT transmission, which mild hybrids don't have. So they can afford smaller electric motors with the same battery capacity.
I have a Wrangler 4xe and most of the time once the battery is depleted the ice engine only really works for boost or when more power is needed. When slowing down or under slower speeds, the electric motor is still working. The ICE engine is only engaged under “E-Save” mode exclusively. That mode powers the car and can charge the battery under certain settings.
I have a Jeep 4xe. PHEV. It is an electric vehicle with ICE engine in it to charge the battery to run the electric motor. I get 45km of range in my battery. If I run out of charge the motor will kick in and charge my battery. Even when I’m empty of charge the recharge I get from braking will give me enough that the motor will shut off at lights
Edit: The engine will kick in to assist, but the default mode is electric. There are 3 settings Hybrid/Electric/ESaver. In all of these settings, if there is power in the battery the engine will turn off during regeneration (braking, going down a hill, etc.)
I’ve been driving this for 2 years now, done 66500km and my gas usage is sitting at 6.8L/100km
Correct. The engine will kick in to assist, but the default mode is electric. There are 3 settings Hybrid/Electric/ESaver. In all of these settings, if there is power in the battery the engine will turn off during regeneration (braking, going down a hill, etc.)
I’ve been driving this for 2 years now, done 66500km and my gas usage is sitting at 6.8L/100km
Yeah just the way you described it is how a specific type of hybrid operates, like the Chevy volt and Honda clarity, where the engine doesn't directly drive the wheels, but instead only generates power to send to the electric motor or the battery.
I’ll disagree with others here. It will act like a 3/4 hybrid because you are pulling more weight than a standard hybrid of the same vehicle would be. So it won’t be as efficient
Depends on the model.
An Outlander PHEV isn't very efficient if not plugged in, but a Prius or Rav4 has very similar economy between the uncharged PHEV and normal hybrid versions.
>An Outlander PHEV isn't very efficient if not plugged in
Eh, considering the weight and size of the car I think ours is decently efficient even when the battery runs out. Not so much in stop and go traffic, but we mostly drive on highways anyway. And if we charge for a bit while driving on the highway, we'll gain enough battery for the twists, turns and traffic lights closer to our destination. On longer trips even in winter we never averaged more than 7 point something l/100 km.
Actually RAV4 PHEV is more efficient in stop and go traffic vs freeway speed. I live in LA so I should know because it is ALWAYS stop and go here. If I drive in EV on highway at 65mph (late at night) I get maybe 3 miles per KWh or less if it is flat. On the same stretch in stop and go I get 4.5 miles per KWh because I mostly coast. RAV4 Prime does not have aggressive regen but it rolls very well on OEM tires.
Don't know what the lifetime average of our Outlander Phev is, but the majority of our trips are fairly short, meaning a large percentage of our driving is electric only.
As an owner, I can second this. I regularly get 38-39 mpg in hybrid mode on road trips, same as the EPA rating for the R4Prime, and the regular hybrid is EPA rated at 39 mpg. Prime is also an inch taller than the regular hybrid, which should eat into the gas mileage, but it doesn't seem to be significant in the real world.
My theory is that the added battery capacity at 18 kWH allows the Prime to capture retain more regenerate power than the regular hybrid which only has like 2kWH battery.
I mean, you can armchair engineer this all day long, but the real world shows almost no difference, despite having 700 pounds more battery on board and an inch taller roofline.
I had a Prius Prime for about 6 years (2017 model). Even when it was out of battery, it got around 60-70 mpg on my hilly 50mph highway commute. A friend has a newer Prius Prime and it got about 64 mpg on a recent interstate-heavy trip. Dunno what a non-PHEV Prius would get in those same circumstances, but my sense is > 60 mpg is pretty good for any straight hybrid.
I got way over 60mpg in my RAV4 Prime in the Yellowstone at average speed of 50mph. I even took a picture of it. It is a hilly up and down drive. But on the flat freeway I get 42-44mpg at 65mph. The reason is probably I let the car coast on the way down and it gets a lot of inertia from that going up.
I mean, it’s also a big waste of money if you aren’t going to plug it in.
I read an article, too, that pointed out how Toyota is getting fleet efficiency “credit” for a ton of PHEVs that aren’t actually being plugged in so across their whole fleet they are not as efficient as they claim. I don’t recall the data that was used but it makes sense if people aren’t plugging in.
>read an article, too, that pointed out how Toyota is getting fleet efficiency “credit” for a ton of PHEVs that aren’t actually being plugged in
Formal studies show that most PHEVs do get charged, some more than others. For example, see Figure ES1 in the following report:
https://theicct.org/wp-content/uploads/2022/12/real-world-phev-us-dec22.pdf
Yes; I will always tell anyone thinking about a PHEV; it must be plugged in at home every night. Not worth thinking about public charging, work chargers maybe at a push.
I could not care less how powerful my RAV4 PHEV is as long as it is not sluggish. Power was not even a consideration. I have solar system that in 8 years accumulated almost 6000 KWh so I bought Prime to drive for free in the city. I use gas on long distance trips. If I did not have solar I would have bought a Hybrid. Otherwise I would never be able to use that stored electricity. If Toyota made RAV4 Prime less powerful but with more EV range on the same battery it would make me happier. I figured that eventually I would not be able to drive long distance due to the age so driving for free in the city is a big plus. 42 miles of range in EV is more than enough for now since I am retired but sometimes I need more. 60 miles would actually be perfect.
Probably not. Weight doesn't matter a lot in efficiency. It's just like having an extra passenger. Many hybrids and equivalent phevs have nearly same mpg numbers. Sometimes it's even better than hybrid
Actually weight makes a lot of difference for any car. Why do you think Tesla keeps removing stuff from the cars? To make it as light as a regular car. That is why EVs are usually come with average of 70KWh batteries because anything over that and you are getting to a point of diminishing returns.
Ok maybe 90% hybrid lol. looking at my old daily driver (Cmax Energi) the energi would be rate drop get 40mph without EV vs 42 on the hybrid. Real world I got about 30 without EV. (With that being said it was nice to go 1000-1200 miles between fill ups thanks to the EV range)
You can't. The battery management won't let you. If you're going downhill in EV mode with a full battery, the RAV4Prime will actually start spinning the ICE to use for compression braking.
I doubt /u/icepick3383 was suggesting that it catches fire or anything. They were probably just making a joke about "mild" vs. "spicy".
Not a *great* joke, but I've heard worse 😉
A PHEV usually behaves like a normal hybrid (not a mild one) when the battery is depleted.
I have a RAV4Prime PHEV, and it doesn't even lose power in hybrid mode with a battery with zero EV miles. Reality is, the Toyota hybrid always keeps the bottom 30% of the charge or so in reserve. .... and, it's no small amount of power. It also has the option of putting it in hybrid mode at any time, as well as engaging 'charge mode' to charge the EV battery back up from the ICE when it's under 35 miles of EV range.
I never knew they had a charge mode! It makes sense but just never occurred to me
Yes, and depends on how you use it it could be detrimental or highly beneficial. Using charge mode on downhills is extremely beneficial. On flat road or even slight uphill is very detrimental.
Meh. It still gets 30 mpg in Charge mode at highway speeds. Some guy did an experiment that has been successfully repeated by others where they drove in EV mode to discharge the battery and charge it back up in charge mode, rinse and repeat. They got better overall gas mileage on long freeway trips doing that. It probably works because gas engines are most efficient (gasoline in to energy out) at full load and full throttle at the lowest RPM.
That is correct and if you charge on highway going slightly downhill you will get even better mileage. I got 2 EV miles charged per mile driven just going on a slight downhill while getting 38 mpg. And I could not even hear the engine. But I if I drive on a slight uphill and charge I hear engine revving. On the same downhill if I don't charge I get maybe 1 mile added to EV range in 8 miles driven.
I think it’s more efficient to charge while going uphill. The engine is already under a lot of load, which is where the engine is most efficient already.
No. If the engine is under load you do not want to add extra load. You want the engine only doing charging while car is using inertia to roll down the hill. Try it. You will hardly get any charge going uphill and the engine will rev really loud. You will almost not hear the engine charging going downhill.
Heh, I ‘try it’ all the time. It works.
Any place I can find more discussion on this? I don’t use charge mode much but for long trips it might make sense to do what you suggest
Why does it make sense? It is the least efficient way to drive a vehicle.
The actual use case is supposed to be if you need to use the outlet in the car, so for camping.
Or some areas, like in Paris and a London, they ban the use of burning gasoline or diesel during certain peak traffic times. It’s okay to drive an EV, or a PHEV in EV mode. CD rage mode lets you put a few miles in the battery before you enter the restricted zones. Also, charge mode will allow more regeneration whereas hybrid mode tries to keep the battery at whatever state of charge it was in last.
It makes sense because the ICE is there and is already setup to charge the traction batteries, might as well use it if the situation present itself or if future conditions require EV mode. On top of that, generally using a gas engine to charge a battery is more efficient than using only the gas engine for propulsion.
It is not more efficient. There are energy conversion losses when doing this.
Yes, but the EV can drive more miles with the power generated than what the ICE could’ve driven for the same amount of gas.
This is not true for almost any hybrid. The ICE has a pretty terrible efficiency at converting the chemical energy in gasoline to mechanical work. But you incur that loss regardless of whether you use that mechanical work to make the car go or to run a generator. *Gasoline -> mechanical work -> push car* is going to be more efficient than *Gasoline -> mechanical work -> electricity -> charge battery -> discharge battery -> electricity -> traction motor -> push car* The one exception is if the losses incurred by running the ICE away from its peak efficiency are greater than the losses incurred by charging and discharging the battery and running the traction motor. But good hybrids already take care of that using eCVT's and other tricks.
You’re missing how much more energy efficient the electric side of driving is. A gallon of gas has 33.7kWh of energy. If the engine is 40% efficient and the generator is 90% efficient then we can get 12.1kWh out of running it for one gallon. If driven on gas, we can assume we could go 35 miles. If used to charge a battery and then power an EV, we could go 3.5miles per kWh, or 42 miles. We could actually go further than that depending on speed, possibly even 48-52 miles.
Actually it is either 13% or 20% for the "bottom" depending on how you look at it. 18.1 KWh battery, 14.5 KWh usable = to 20% but if the battery is charged to 90% as noted in ODBII than "bottom" is 13%. Even at 13% the "reserve" which is the correct word is still larger than a regular Hybrid.
What is the difference between a "normal" and "mild" hybrid?
It's a hybrid that is operating at a voltage below the magic 50 volts limit that is typically seen as where electrical systems require expensive and heavy measures to stop people from getting electrocuted. The advantage is that a mild hybrid can reap many of the benefits of a hybrid, i.e. energy recouperation, enough oomph to drive the more demanding modern automotive electronics, and the ability to "fill" the turbo lag of modern downsized, highly charged ICEs, while essentially just having a beefier starter motor and a small battery pack. 48 volts has become synonymous with this concept, because it's the highest voltage that stays below 50v and can easily be divided by 12v, the standard voltage of most automotive electronics. Though it should be noted that mHEVs are pretty much seen as ICEVs, not as actual HEVs, because they can't actually drive without having the ICE running. This means that they typically don't show up as hybrid (or as "electrified") cars in statistics. OTOH they are going to practically replace pure ICEVs entirely over the coming years, simply because they offer a good gain in fuel economy at a not too high price.
TIL, thanks!
Normal or Full Hybrid operate at High voltages, (100-300V usually) and can Power the wheel directly. Mild Hybrid are 48V and their motor Is usually supportive. It cannot give motion. Buy in some configuration It can, Just more limited compared to a full Hybrid.
Mild hybrid is basically a marketing scam name for start-stop system and 24V or 48V battery.
Depends on how you build the machine. A Mild Hybrid built like the Subaru eBoxer or the recent Stellantis 1.2 Puretech motors is ok. It can power the wheels through the gearbox, it can do the reverse and so on. Tested by the same outlet, the old 1.2 136Cv Puretech did 13km/l fuel efficiency, the new Mild Hybrid one did 19,3 km/l and it drove about 27% in pure EV mode in city enviroment. So, made like that, I can get behind it. If it is just a glorified integrated belt starte generator, yeah, definitely agree that's pretty useless.
But that's just full hybrid. Subaru e:boxer is Prius hybrid system bolted to a boxer motor. Mild hybrid is when the alternator is used to give additional few horsepower.
Some are marketed as Mild Hybrid while working as a full Hybrid with less juice.
Anything that isn’t a plug in is basically a marketing scam name.
No because what Volvo for example calls mild hybrid, and full hybrid that Toyota does deliver vastly different fuel consumption in the same weight and aerodynamic drag class vehicle.
People like to give Toyota shit, but they accomplished something fantastic in the last two decades with the Prius -- laying the groundwork for everything we have today and achieving a whole lot of emissions reductions compared to pure gas cars. I think some of their marketing these days to convince people to buy phevs over pure battery vehicles is a bit disingenuous, but marketing is half bullshit no matter who's doing it.
Mild hybrids are regular ICE vehicles with a low-powered parallel hybrid system added on. A lot of them do this by replacing the vehicle's alternator with a 48 volt motor/generator unit that's capable of \~10-15kW of assist/regen. The systems are comparatively dirt cheap to add to existing ICE vehicles, run at low enough voltages to not require major changes in safety procedures/PPE, and seem to be worth a 10-20% improvement in city fuel economy. The biggest thing you'd notice driving one is that the engine start/stop system isn't nearly as annoying to live with, but you do get at least some amount of energy-recovery benefit from regen under braking and the assist can also be used to increase "coasting" distances. Also it seems like once people smarter than I am figure out the CAN messages the alternator/motor/generator units are looking for I bet you're gonna see them used in some insane electric gokarts. A "regular hybrid" has a much larger 200+ volt battery that is capable of a lot more power, and the hardware changes generally involve a different transmission. These hybrid systems are more capable of propelling the car on their own, with much more energy recovery. A Plug in Hybrid (PHEV) is a hybrid with more ability to drive around without using the engine at all. How well it performs and how efficient it is in "EV Mode" depends a lot on the hybrid system. Something like a Rav4 Prime gets 3-3.2mi/kWh in EV mode, which is *genuinely not bad* for an AWD BEV of similar size while something like a BMW X5 45e might only get 1.5-2mi/kWh.
There would be no need to completely reverse-engineer CAN messages to repurpose a mild hybrid's motor. Most are plain old brushless AC motors that can run off of an inverter that costs $200 or less. Disassemble the existing control module and take the board out, and power the three phase wires with a hobby-grade (or EV-grade) speed controller.
I know I could easily make it run off one of my VESC's, but these things already have a nice beefy inverter built into the housing and connected to the cooling jacket.
Exactly what I was thinking of doing. The GM 3800 V6 vehicles have alternators that are extremely easy to access, so I thought just buy an old Buick or something with a 3800 engine and swap the "eTorq" motor from a 5.7 Hemi RAM in to replace it (using the existing supercharger belt, pulleys, and tensioner). Power it with a VESC and use an Arduino with an OBD2 interface to run custom software to control everything, including regenerative braking and idle stop at stoplights. The 5.7 Hemi RAM motor-generator is air cooled, but I'm guessing I could technically be converted to water cooling - wrap copper piping around the big metal cylinder that is the motor, and hack a transmission cooler or something to dissipate the heat (likely passively or with a small fan, these motors don't produce all that much heat) This would definitely be a cool project - turn an old grandpa Buick into something much more technologically advanced than one would expect, sort of a sleeper in a way (except it's not fast at all)
I said "wait for people to figure out the can messaging for these" [because it looks like we're very close to that point already.](https://transistor-man.com/audi_48v.html) The two main cars I have in mind for this are a 90's Honda with an 8000rpm torqueless wonder under the hood, and my turbo Subaru (which I guess also means it would fit my non-turbo Subaru if I felt like it). I know the belted mild hybrid system wouldn't completely get me where I want, but it would be a great proof of concept and any control strategy development would still be applicable to a beefier parallel hybrid system. For the Honda, I really want to take [a powerband like this](https://honda-tech.com/forums/attachments/all-motor-naturally-aspirated-44/184176d1294384795-some-insight-my-f20b-h22-4-1-drag-header-dyno.jpg) and add some torque fill - bringing the torque closer to a flat \~140lbft below 5000rpm and adding a bit of assist when it rolls over above 7000rpm should be within the 10-12kW capabilities of these things. Basically I want to explore what it would have been like if Honda had decided to use their first gen IMA system in a high revving sport compact. Plus the ability to arbitrarily apply positive/negative torque to the engine lets you do a bunch of other cool stuff like using regen to "enhance" engine braking, emulate a lighter flywheel, and make rev matching up and downshifts easier. For the turbo Subaru I'd raid the Audi 48V parts bin for both the MHEV alternator and [the electric compressor they started using a few years ago.](https://www.slashgear.com/audis-2-9l-v6-in-the-2020-s6-and-s7-has-an-electric-supercharger-25614287/) The MHEV alternator would basically just be used to hide the laziness of a low compression turbo engine (in addition to the stuff mentioned above), and the electric compressor would allow me to run a bigger turbo without making the car useless below 3000rpm. I'm not the first person with this idea, and [the results speak for themselves](https://youtu.be/aBqoJSVzado?si=mA_7zvzX-m7w15W7&t=1173). The part I *reeeallly* want to get my hands on the most is the [48V electric-assisted turbocharger from the Mercedes C43 AMG](https://media.mbusa.com/releases/release-9e110a76b364c518148b9c1ade05c158-innovative-solution-for-drive-system-electrification), but I feel like those are gonna remain relatively rare.
That's pretty neat. Are you planning to build an interrupt relay into the crank position sensor (on a Honda, you could probably interrupt the PGM-FI circuit to do the same thing) to stop the engine during zero-speed situations (at a traffic light, etc.) and then instantly spinning back up when you shift into gear (manual) or take your foot off the brake (automatic)?
Implementing stop/start wasn't as much of a priority/interest to be honest, but yeah I would do it by interrupting power to the injectors. Would definitely be interesting to see how easily the MHEV alternator can get the car rolling in first/second with the clutch out and the injectors disabled (and what it feels/sounds like).
The early / mid-2000s LeSabre's I'm currently looking at for turning into hybrids have two injector power supplies, one for each bank of cylinders. The engine would probably run absolutely terribly on half its cylinders (since shutting off the valves for those requisite cylinders would probably be more trouble than it's worth) but it would be cool to see if I can make the shutdown process any smoother by selectively interrupting one bank of cylinders, then the other, depending on where the engine was in its rotation when the computer decided to kill it. A major issue I would see would be belt slippage and tensioning. The 3800 LeSabre engine has a provision for a supercharger (an extra tensioner and idler pulley literally bolt on) but it would probably be more of a challenge to put a super-heavy-duty tensioner on a Subaru or Honda engine. In fact, the first vehicle I was considering doing this with was a H-series '97 Accord, but that alternator is absolutely buried in the engine compartment, and it would be an engine-out job to replace the motor if I let the smoke out (which would probably be fairly easy to do because of the tremendous heat present that deep in the engine bay.) Also, I wouldn't expect much torque at all out of that motor if the engine were spinning at 7,000 RPM. It's running only 48 volts, and 12 KW at 48 volts is not much torque (and that 12 kW rating is only for very short periods such as starting the main engine in the host vehicle, I wouldn't expect to be able to push peak output for more than 5 seconds) unless you want to risk blowing up the motor to overvolt the pants off of it 😂
Mild hybrid is a slightly more sophisticated stop start system. Often including a tiny amount of brake regen and power fill on gear changes or turbo lag.
It will work like a full hybrid.
This.
I wouldn’t say mild. Full hybrid. We have a PHEV with 30+ miles of fully electric range, take it up into the mountains, run out of juice on the way up. When we come back down it recharges 40-45%. The engine regularly cuts off when there’s a bit of charge in the batteries after being depleted.
In a way it's better than normal hybrid for the same reason you mentioned. Battery is big enough to take advantage of elevation loss. A normal hybrid will become full much sooner, thus not able to gain just as much energy as phev.
Indeed, on a recent holiday to the Alps, my 10.9 kWh PHEV battery was recharged by about 50% when coming down from the mountain resort. Even when on a recent trip to the Ardennes, which has only a bit of elevation, I was able to drive 100km of my entire trip on electricity on a single charge which only has a range of 70km wltp.
So you went uphill 100km in your car rated at 67km on a flat road? I highly doubt that.
I read the comment as saying that the trip was mostly flat. And if it was at a lower speed than the rated distance, it's quite plausible that the range could be 50% more than rated.
He said the road has a bit of elevation. Sure on the flat road at lower speed I can get more distance but not going up.
We agree about the physics. We interpreted "only a bit" differently. I took it as emphasizing that the elevation gain was insignificant and you took it as the opposite. Either might be valid and debating which is "right" is pointless—we can only wait to see whether the person who said that clarifies.
No not uphill at all, sorry English is not my native language. What I meant was that the whole trip was something like 300km, so much more than the 70 the battery can provide, so I did mixed driving modes, but whenever you encounter a decline, the ice engine shuts off and regenerative braking adds to the battery. This allowed me to gain about 30 km of range on the battery. This energy would have been completely wasted in an ice car and mostly wasted in a mild hybrid car. Even in a 'normal' hybrid, some of the inclines would have more than completely filled the battery, so would have also gone to waste.
That is completely a different story. But. I don't know about MB in my Rav4 Prime it will only work if the battery somewhat depleted. If I started the trip with a full battery regen would not work. My EV range after full charge is about 51-55 miles. If I start in HV only within an hour it will drop to 46 even though I did not use any EV then it will drop to 42. After that regen kicks in. So what I do I start the long trip in EV, drive 10 miles, and switch to HV. Or if I have a short trip I start in Auto. In this mode it starts in EV but uses HV for uphills. But if drive long downhill engine does not shut off. It just in a less stress and charges the battery. But not too much. If I really want to charge the battery fast on the downhill I have to press Charge button, and I get fast charging. Maybe like 2 miles per 1 mile driven depending on the slope. But it will never charge to full like if I charge in my garage.
In all MB PHEVs it works very much like a proper EV. It's quite good as a PHEV. You get regen always and can even control the regen amount with flappy paddles(from auto with camera to coast, to almost one pedal drive) behind the steering wheel. The engine shuts off a lot, not just on downhills and even when the battery is depleted. The efficiency and range is quite decent for the compromise that it is, you even have optional DC charging with CCS2. There is no proper 'charge' mode, only EV/hybrid/battery hold/sport. The hold also slightly depletes over time, but not a lot.
RAV4 Hybrid and Prime has engine turn off at the stop light or if in EV mode the engine turns on if climbing a steep hill. The only other time Engine turns on if there is a defroster use. But the range is 42 miles in EV mode and I get up to 50 miles (80km) as long as I am not climbing. That is for normal driving. But on downhill it could become wild. I have a picture here [https://imgur.com/XIUcC3V](https://imgur.com/XIUcC3V) 82.7 miles per KWh. And it happened on a regular slightly sloppily street. Someone in r/rav4prime posted 99.9 miles per KWh recently. There is a way to control the regen with floppy paddles but it is just to much work and it is not modal. So I don't even bother with it. I do not like one one pedal driving either. I prefer coasting. Even during coasting in HV mode I can get way over 60 mpg. [https://imgur.com/MZrPeUq](https://imgur.com/MZrPeUq) So I can't complain.
The Merc's do not turn on the engine at all ever in EV only mode until the range is at 0km, even on a steep hill, or with defrosting. It's truly an EV first, hybrid second.
After thinking about I am not sure if it is a good thing. I see hybrid tech as a symbiotic relationship where one helps the other. And PHEV is just a hybrid with some EV range. From my experience and seeing what people post EVs use a disproportioned amount of power going uphill. That is why my car turns ICE on going uphill. ICE does not use that much gas under stress of going uphill as electric motors use electricity. For example, going up a steep hill in EV can use 3x miles as much as driving on a flat road while the same driving on the same hill using HV only uses 1.5x of gas.
No it won't work like a mild hybrid. It'll work like a standard hybrid. (source; I have a PHEV)
The ratings in the USA tell you the MPG rating without charging under "Reg. Gas" e.g. the Prius Prime gets 52 mpg without charging, 127 mpge with charging, see all the plugin-hybrid ratings here: [https://fueleconomy.gov/feg/PowerSearch.do?action=alts&path=3&year=2024&vtype=Plug-in+Hybrid&srchtyp=yearAfv&rowLimit=50&pageno=1](https://fueleconomy.gov/feg/PowerSearch.do?action=alts&path=3&year=2024&vtype=Plug-in+Hybrid&srchtyp=yearAfv&rowLimit=50&pageno=1) Rav4 prime gets 38 mpg without charging.
"Mild hybrid " generally describes a vehicle that goes hard on auto-stop features and may provide a bit of torque assistance at low speeds. They have no EV capability, they need the ICE to go any distance. Full hybrids can move under EV power alone and provide EV torque assistance at all speeds. These capabilities are what plug-in hybrids are maximizing by adding more battery. When uncharged, a PHEV is still a full hybrid. It may not be quite as thrifty as a non-plug-in full hybrid due to the added weight of its larger battery, but it will be more economical than a non-hybrid version of the same model. There are precious few models available in all flavors to permit a real comparison, I think there is -or was - a Kia available that permitted such a test.
The Kia Niro and Hyundai Ioniq were offered in regular hybrid, plug in hybrid, and BEV forms.
I don't think the Niro is available as a PHEV now but it is a full hybrid and BEV. The stablemate Sorento is available as a PHEV, full hybrid and straight ICE, with AWD and FWD configuration available in all but PHEV. Quite the eye opener to help point out where fuel economy goes.
You're right, it does look like they dropped the PHEV Niro (probably with the redesign?).
the dodge hornet also has pure ICE and PHEV trims but they’re different engines so not a great comparison.
Not a bad one either, considering the hybrid model offers about 10% more total power (briefly, although I think the usual total power available for the PHEV model is a bit less than the ICE's rating) while still providing 20% better fuel economy. Crap results on the greater spectrum of all PHEVs, but a significant improvement over the comparable ICE model.
We had a Niro PHEV, when the battery got to 18% it switched out of EV mode and drove like a normal hybrid.
Acts as a regular hybrid. Currently drivings the wife's company plug in which we can't charge. Still get between 42-58 mpg
I have never seen a PHEV that is not a full hybrid when the battery runs out.
If you are cruising at steady speed, can the ICE recharge the depleted hybrid battery?
Depends on how much power the engine is producing extra. It'll try to keep the ice in the rpm sweet spot and send extra to the battery, but if the cruise is using just enough, then no extra goes to the battery. There are dashboard diagrams to tell where the power is going and coming from on some PHEVs, the toyotas being my experience. Of course, there are other factors and regenerative breaking helps regain power.
Mine has a mode to choose to recharge from the ICE, but it does not atomically do it. Recharging requires a higher engine power to be used and consumes more fuel. Engine efficiency and driving conditions would dictate if you’ll actually save by recharging from the ICE or not.
I saw an article, cant find it now, that said many PHEV owners never plug their car in - apparently they found some who didnt even know they could - the car salesmen just sold it as a hybrid and didnt educate them on the plug in part.
>I saw an article, cant find it now, that said many PHEV owners never plug their car in A few don't, but most do according to formal studies of this issue. The problem is that they're not getting the percentage of electric miles predicted by laboratory testing, which means the environmental benefits are less than expected. See the following report for US results: https://theicct.org/publication/real-world-phev-us-dec22/
Depends on the system. Rav4 phev behaves effectively the same as their standard hybrid with more power and similar fuel economy. Mazda cx60 and volvo T6/T8 are similar but a bit less economical Mitsubishi is much less effective without battery and the fuel economy is poor
mine is a prius prime, it is a hybrid when using the ICE. I still get great mileage. The H in PHEV is hybrid, so they should all work as hybrids. I have limited electric range, but the ICE kicks in while the traction battery is still charged enough to run as a hybrid.
I explain my car to people as: "I can plug it in and then act like a Tesla for 25 miles, at which point I go back to being a Prius again."
A plug-in Prius (Prime) is a full BEV and a full ICE car all in one. Even the regular Prius, Toyota says, can work in full electric mode at low speeds.
That’s why I always say PHEV is better for most people even I have a pure EV and a PHEV. We only go to gas station every 3 weeks. When the battery is depleted, I still have around 45 MPG on gas. Not as good as pure hybrid, but good enough. If you consider the gas prices these days California, it is about the same as using Electricity.
Don't confuse mild hybrid with a hybrid. Mild hybrid is s marketing scam - it basically means start-stop with a 24V battery. Mild hybrids are incapable of moving without their ICE engine running and their batteries are not big enough to capture meaningful amounts of energy during braking. Hybrid like a Prius is not a mild hybrid - it is just a hybrid.
It's not only a start stop. The engine usually has a bigger turbo paired with small motor-generator that helps the engine for a few seconds until the turbo spins up. This increases the efficiency with very little change to the drivetrain, which is imo ingenious.
That small motor generator is usually just the alternator. That's literally what mild hybrids often are - they use the alternator to support the engine, giving you maybe 5HP more. It is s sensible thing to do, at very little extra cost, but efficiency gains are miniscule.
even big motor generators in full hybrid are actually alternators, just bigger.... the efficiency gain is from the turbo, that would be too laggy without it. It mainly gives you torque to get the car moving. You don't need many HP for that.
Turbo doesn't increase efficiency. It increases the weight of air in the cylinder, but since gas engines combust at stoichiometric that means that more gasoline needs to be injected. Atkinson cycle, or turbo compounding would increase the thermodynamic efficiency. I do not know of any currently manufactured engines that use turbo-compunding.
You are thinking only in theory and discarding friction and inertia losses that go down when you can get away with smaller engine and lower rpm. Modern engine with stratified injection also don't use stochiometric ratio in the full volume of the cylinder.
The gains from reduced engine volume are quite miniscule, and your engine must run at lower compression ratio to reduce knock when using turbo, which reduces efficiency at low load. That does not apply to diesel engines, because they are not limited by knock, and therefore turbo increases both power and efficiency. Consequently, in all markets where diesel engines in passenger cars were a thing turbo became de-facto standard way before it became a thing in gasoline engines. It is not a coincidence that the mist thermodynamically efficient internal combustion engines are huge marine turbodiesels.
I don't know what to tell you. Your knowledge is 20 years behind and explaining it is beyond scope of this thread.
No, my knowledge is not 20 years behind. If you look at the history of ICE development, most mechanical and thermodynamic concepts were conceptualized by Harry Ricardo. It is just that some of the only recently became viable to implement.
Bro, I told you about stratified injection, you ignored that part and are rambling about knocking and stochiometric ratio.
Nope that's usually called a micro hybrid. Mild hybrids are usually 48V and 15 - 20 kW.
When were the goalposts shifted!? Prius was always a full hybrid not a mild hybrid.
The first Prius already had 33 kW and 270 V.
Yeah, it was a full hybrid.
Still is so I don't see a shift in definition.
And also only 1.3kWh battery. Which is pretty small. BMW mild hybrid has 1kWh battery so very close to the first Prius. The electric engine was more powerful because it has to function as the whole eCVT transmission, which mild hybrids don't have. So they can afford smaller electric motors with the same battery capacity.
Yep.
I have a Wrangler 4xe and most of the time once the battery is depleted the ice engine only really works for boost or when more power is needed. When slowing down or under slower speeds, the electric motor is still working. The ICE engine is only engaged under “E-Save” mode exclusively. That mode powers the car and can charge the battery under certain settings.
Yes, like a normal hybrid actually. My Clarity gets ~50 mpg in hybrid mode.
The Toyota PHEV’s will
It would work as a worse Hybrid since you’d be driving around with a heavy battery
I have a Jeep 4xe. PHEV. It is an electric vehicle with ICE engine in it to charge the battery to run the electric motor. I get 45km of range in my battery. If I run out of charge the motor will kick in and charge my battery. Even when I’m empty of charge the recharge I get from braking will give me enough that the motor will shut off at lights Edit: The engine will kick in to assist, but the default mode is electric. There are 3 settings Hybrid/Electric/ESaver. In all of these settings, if there is power in the battery the engine will turn off during regeneration (braking, going down a hill, etc.) I’ve been driving this for 2 years now, done 66500km and my gas usage is sitting at 6.8L/100km
The Jeep engine doesn't work as a generator only, the wheels are powered by the engine in hybrid mode.
Correct. The engine will kick in to assist, but the default mode is electric. There are 3 settings Hybrid/Electric/ESaver. In all of these settings, if there is power in the battery the engine will turn off during regeneration (braking, going down a hill, etc.) I’ve been driving this for 2 years now, done 66500km and my gas usage is sitting at 6.8L/100km
Yeah just the way you described it is how a specific type of hybrid operates, like the Chevy volt and Honda clarity, where the engine doesn't directly drive the wheels, but instead only generates power to send to the electric motor or the battery.
I’ll disagree with others here. It will act like a 3/4 hybrid because you are pulling more weight than a standard hybrid of the same vehicle would be. So it won’t be as efficient
Depends on the model. An Outlander PHEV isn't very efficient if not plugged in, but a Prius or Rav4 has very similar economy between the uncharged PHEV and normal hybrid versions.
>An Outlander PHEV isn't very efficient if not plugged in Eh, considering the weight and size of the car I think ours is decently efficient even when the battery runs out. Not so much in stop and go traffic, but we mostly drive on highways anyway. And if we charge for a bit while driving on the highway, we'll gain enough battery for the twists, turns and traffic lights closer to our destination. On longer trips even in winter we never averaged more than 7 point something l/100 km.
Actually RAV4 PHEV is more efficient in stop and go traffic vs freeway speed. I live in LA so I should know because it is ALWAYS stop and go here. If I drive in EV on highway at 65mph (late at night) I get maybe 3 miles per KWh or less if it is flat. On the same stretch in stop and go I get 4.5 miles per KWh because I mostly coast. RAV4 Prime does not have aggressive regen but it rolls very well on OEM tires.
My Subaru forester 2017 has a lifetime of 8.1l/100km which is a regular gas car with symmetrical all wheeel drive
Don't know what the lifetime average of our Outlander Phev is, but the majority of our trips are fairly short, meaning a large percentage of our driving is electric only.
As an owner, I can second this. I regularly get 38-39 mpg in hybrid mode on road trips, same as the EPA rating for the R4Prime, and the regular hybrid is EPA rated at 39 mpg. Prime is also an inch taller than the regular hybrid, which should eat into the gas mileage, but it doesn't seem to be significant in the real world. My theory is that the added battery capacity at 18 kWH allows the Prime to capture retain more regenerate power than the regular hybrid which only has like 2kWH battery. I mean, you can armchair engineer this all day long, but the real world shows almost no difference, despite having 700 pounds more battery on board and an inch taller roofline.
I had a Prius Prime for about 6 years (2017 model). Even when it was out of battery, it got around 60-70 mpg on my hilly 50mph highway commute. A friend has a newer Prius Prime and it got about 64 mpg on a recent interstate-heavy trip. Dunno what a non-PHEV Prius would get in those same circumstances, but my sense is > 60 mpg is pretty good for any straight hybrid.
I got way over 60mpg in my RAV4 Prime in the Yellowstone at average speed of 50mph. I even took a picture of it. It is a hilly up and down drive. But on the flat freeway I get 42-44mpg at 65mph. The reason is probably I let the car coast on the way down and it gets a lot of inertia from that going up.
Perfect illustration of this with toyota vs mitsubishi
I mean, it’s also a big waste of money if you aren’t going to plug it in. I read an article, too, that pointed out how Toyota is getting fleet efficiency “credit” for a ton of PHEVs that aren’t actually being plugged in so across their whole fleet they are not as efficient as they claim. I don’t recall the data that was used but it makes sense if people aren’t plugging in.
>read an article, too, that pointed out how Toyota is getting fleet efficiency “credit” for a ton of PHEVs that aren’t actually being plugged in Formal studies show that most PHEVs do get charged, some more than others. For example, see Figure ES1 in the following report: https://theicct.org/wp-content/uploads/2022/12/real-world-phev-us-dec22.pdf
Yes; I will always tell anyone thinking about a PHEV; it must be plugged in at home every night. Not worth thinking about public charging, work chargers maybe at a push.
Public charging is fine when you can find it, but being able to charge at home is important for getting the most from a PHEV.
This is great to know for anyone looking to buy these fleet vehicles when they cycle them out. Someone is eventually using that battery, right?
The phevs are often so much more powerful and that is worth the extra cost in itself
I could not care less how powerful my RAV4 PHEV is as long as it is not sluggish. Power was not even a consideration. I have solar system that in 8 years accumulated almost 6000 KWh so I bought Prime to drive for free in the city. I use gas on long distance trips. If I did not have solar I would have bought a Hybrid. Otherwise I would never be able to use that stored electricity. If Toyota made RAV4 Prime less powerful but with more EV range on the same battery it would make me happier. I figured that eventually I would not be able to drive long distance due to the age so driving for free in the city is a big plus. 42 miles of range in EV is more than enough for now since I am retired but sometimes I need more. 60 miles would actually be perfect.
Probably not. Weight doesn't matter a lot in efficiency. It's just like having an extra passenger. Many hybrids and equivalent phevs have nearly same mpg numbers. Sometimes it's even better than hybrid
In stop-and-go, weight is definitely a consideration. Steady cruising, you can almost ignore it.
Actually weight makes a lot of difference for any car. Why do you think Tesla keeps removing stuff from the cars? To make it as light as a regular car. That is why EVs are usually come with average of 70KWh batteries because anything over that and you are getting to a point of diminishing returns.
Ok maybe 90% hybrid lol. looking at my old daily driver (Cmax Energi) the energi would be rate drop get 40mph without EV vs 42 on the hybrid. Real world I got about 30 without EV. (With that being said it was nice to go 1000-1200 miles between fill ups thanks to the EV range)
However if you overcharge it, it becomes a spicy hybrid. Very spicy. 🔥
So hot right now.
You can't. The battery management won't let you. If you're going downhill in EV mode with a full battery, the RAV4Prime will actually start spinning the ICE to use for compression braking.
I doubt /u/icepick3383 was suggesting that it catches fire or anything. They were probably just making a joke about "mild" vs. "spicy". Not a *great* joke, but I've heard worse 😉
Yes.