Comment by jostmey
15 hours ago
I'm surprised there isn't more effort to create hybrids in reverse--an electric car with optional gas generator. The gas generator could run at constant speed, never changing RMP, while the battery handles constant changes in acceleration. The idea is not mine. I've heard about it in China
TFA is exactly that...
I think it's also because EREVs need a performant generator that isn't much different from the drive motor. So you'll have a full ICE+EV drivetrain on top of an EV as its battery for it to work, which is not ideal.
Compared to that, other hybrid systems like the motor-clutch combo packs that sit between the ICE and gearbox, as well as the fixed gear Toyota systems, can have motors that are weaker, lighter, and cheaper than the ICE, while being able to be additive to the ICE power output. That makes more efficient use of steel and copper than full serial setups.
BMW i3 had such EREV option, but it apparently used a cheap OEM bike engine(not like a BMW Motorrad engine) and also could not overcome power draw of the EV drive motor. So it literally just extended the range, not allowing it to run indefinitely at highway speeds with just refueling. Nissan e-POWER system is powerful enough to do that, but then the readers of comment will have to back to the line 3.
I've done some long trips with my i3. The key is to turn the engine on when the battery reaches 75%. The battery then absorbed the large power draws when accelerating or going up big hills. The engine does vary in RPM depending on my power draw, and by the end of my trip, the battery is usually not significantly lower, maybe around 60%. I usually turn off the engine when I'm almost at my destination so I can use the remaining battery energy.
People claim the EREV i3 won't do extended highway but I did Boston MA to Wichita KS in one shot in my 2014 with a hurt battery using Hold State Of Charge mode starting at a 75% battery charge and using a 7 gallon fuel cell in the frunk with a transfer pump to allow longer stretches between refueling. It worked a treat. I have since removed the additional fuel system once I got to Wichita and now it is my daily commuter and goes 2000+ miles between fillups.
Yeah. I'd love a decent plug-in EREV in the US. The 2027 Rogue appears to NOT have a plug-in option at the moment.
I can't fathom buying an EV and still only getting 40 MPG and needing to buy gas. Ninety percent of my trips are < 40 miles round trip and could be handled by a modest 15kWh battery. For that last ten percent, I'd happily use some gas to not have to worry about charging on the route.
Mazda had (has?) some cool EREVs using rotary engines as the power plant. Though sadly without plans to bring them to the US.
That is exactly what ePOWER is, that configuration is called a series hybrid and is more commonly seen in heavy industry like diesel trains or trucks in the mines (for better or worse).
More recently effort is also going into series hybrids for public road haulers, which I personally think is a great application for it since you can potentially put a lot of the equipment into a hot-swappable dolly.
I drove a Nissan Note (Nismo esition) with ePower and it could happily spin the wheels when taking off, not something you normally get out of a tiny economy hatchback. I think it has 140kw electric drivetrain? 140kw is pretty sporty when delivered instantly.
There’s a lot of good replies here but I’ll add mine too:
The simples reason is this. What you’re describing is having a gas motor spin a thing (the generator) -> charge battery -> discharge battery -> spin a thing (the wheels) to make car go. Each of those steps has efficiency losses.
That’s why most hybrids are parallel hybrids, where both the gas engine and the battery+motors can spin the wheels more or less directly, even at the same time.
you still basically get the engine spinning at a more constant rpm, and the battery kicks in for acceleration (and charges on deceleration), and now highway cruising doesn’t have any lossy conversion steps, while acceleration and braking uses the advantages of the electric drive chain.
What you are referring to is usually referred to as an EREV (Extended Range Electrical Vehicle). The reason legacy manufacturers market their less efficient plugin hybrid and non plugin hybrids (100% of the power comes from petrol) instead is because that's what they have and want to milk for as long as possible. In terms of drive train these are more complex to manufacture and more costly to maintain than an EREV. EREVs typically have slightly larger batteries than a typical PHEV as well. Typical electrical ranges are at least 80-100 miles or more in some cases. Usually the cars are available as without the range extender as well. This is less common for PHEVs and hybrids. Though of course some legacy manufacturers are still trying to push compromise cars. Like Nissan in this case.
Nissan has been really struggling for the last few years, this new hybrid engine doesn't look like it will turn things around for them to me.
EREVs are an idea that is not new and also relevant in shipping and aviation. Many modern large ships (oil tankers, cruise ships, etc.) are already EREVs effectively: an electrical motor drives the propeller and a generator powers the motor.
And there are are a few plane designs that are using small batteries + generators to power flight. It makes a lot of sense: electrical motors are a lot simpler, lighter and cheaper to maintain. Engine maintenance is very costly in aviation. And so is fuel. The recently announced X1 is a good example of a plane that does this. There are a few other manufacturers working on this as well. Early days but the potentially large fuel savings probably ensure this is going to happen one way or another.
EREVs aren't magic. They make sense for some applications but less efficient than mechanically coupling the engine to the wheels. If the user is going to run mostly on fossil fuels due to trip distance or lack of available battery chargers then a parallel hybrid design like the standard Toyota Prius model is generally a better design.
> In terms of drive train these are more complex to manufacture and more costly to maintain than an EREV
They really aren't, an EREV needs two electric motors and fixed gears connecting to the engine and wheels. Toyota-style hybrids (also Ford, Chrysler, Subaru, Mazda) need... two electric motors and fixed gears connecting to the engine and wheels. Everything else is quite similar, though the hybrid will obviously have much smaller and cheaper batteries, onboard chargers, battery temperature management systems, etc.
Range extender EVs made a lot more sense a decade a go when batteries were much more expensive, and fast chargers were not yet ubiquitous. Then range extenders were more affordable than EVs and could go to places EVs couldn't.
Now these EREVs are mostly luxury niche of big cars (where extra space taken by two power trains doesn't matter) for people who don't want to spend 20 minutes at rapid chargers on that yearly long trip they do. Or for people who live in some global warming ignoring backwater[1] that hasn't built out rapid charger yet.
[1] even China has ubiquitous fast charging network now
We just drove from the UK to Portugal (via ferry). They were in the electric car and anxious about the next charger almost entire time.
The only thing worse than the staple "all chargers except one broken, wait time 1h+", was the ghost charging station existing only on the map - they drove there only to see the empty field instead.
Needless to say we barely made it in time for the ferry (their refueling was about 3 hours total in the UK alone), and sadly won't make me getting EV as the main car anytime soon.
Second, small town car for errands, maybe, but that means having no comfort or equipment I'd like to have in the "main" car (and half of it is safety).
Also - note you seem to suggest the mythical ubiquity of the fast chargers is the solution to the range, but they're also so expensive to use that any savings from the local driving and charging at home (if someone is lucky enough to own a house with garage or off-street parking) is immediately burned on the first longer trip.
There exists a fringe of people who are constantly driving 5+ hours all the time in random directions and places.
These people stoke a lot of fear about EVs despite being a tiny fraction of the population.
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China is the first country I would expect to have ubiquitous fast charging. They are years ahead of the west in the EV rollout. Also high speed rail, robotics, high tech manufacturing in general is kind of their jam now.
> China is the first country I would expect to have ubiquitous fast charging.
Everywhere in China? China is a large place. My money would be on a small rich country that’s (almost) entirely a city. Monaco, Singapore, maybe Luxembourg.
Googling gives me https://transition-energetique.gouv.mc/en/themes/mobility/mo... which doesn’t mention fast C charging but says “Every Monegasque resident is now less than 200 metres from a free public charging point” ⇒ it wouldn’t surprise me if Monaco already meets your definition of “ubiquitous fast charging”
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I's already pretty ubiquitous in many western european countries
In America we don’t have enough chargers for roadtrips.
The capacity issue is specially evident on long weekends or sundays when everyone needs to use the same few chargers.
Just got a Tesla. I was worried about travel through western Iowa, it seemed fairly worst case looking at the map of my route, because I’m not on the interstate and the Tesla superchargers aren’t near my route. To my surprise, it was a non-issue. Modern EVs have enough range and there are indeed just enough chargers.
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Having done many road trips in a Tesla, I don't believe this is true. My trips were in the south west though. I'm sure there are areas where it is a problem but it depends.
I just got back from a Seattle to Yellowstone road trip with an EV and have to agree.
While it was possible to accomplish the mission, it wasn't exactly pleasant and required more planning and longer stops.
I road trip the east coast a few times per year. I haven’t had to wait at a charger for years.
I feel like this road trip thing is over exaggerated. What if we (as a society) rented a Toyota Sienna or something equally boring when we need to go on a road trip?
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Just a note: the Technology Connections video above goes over why this doesn't work well for cars (but does for train locomotives).
Chevrolet Volt (2011) https://en.wikipedia.org/wiki/Extended-range_electric_vehicl...
The Volt was promised to use the gas engine only for range extending but they ended up connecting it to the drivetrain for highway speeds...
The volt was never popular enough, unfortunately. Right around the time we were looking to buy a new car, and had the Volt high on our list, the retired the product line.
GM will go down in history as the auto maker that had nine lives and blew them all on canceling EV and high efficiency products.
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Ford and Ram are both doing this with their next generation electric pickups. Range and towing on pure electric was deemed too compromised.
https://www.motortrend.com/features/what-is-an-erev-extended...
Not for cars, but Edison Motors in Canada seems to be going this route right now for their heavy duty trucks and heavy-duty pickup truck conversions.
Disclosure: I have a small investment in them.
I really love what Edison are doing, I have no skin in the game I just think it's a great business ethos.
Feom a fictional perspective I also dig the rugged blend of electric industrial equipment and utilitarian design. Like a mad-max solar punk, rather than a utopian one.
I picture them pulling up to a makeshift solar outpost en-route, in the middle of the wasteland desert, covered in red dust, the thick sheet metal scarred from raiders...
I really like Edison's ethos as well, although I do worry they make some of the classic startup mistakes of getting a bit distracted on things that aren't important.
That's pretty much how the Chevy Volt worked. It was an incredibly good system in that car and GM did their usual thing and killed it
It seems to me you’re talking about a range extender, which lots of Chinese EV makers use. Many do buy them but sometimes you get the worst of both worlds: weighty like an EV and the heat, vibration, exhaust of a petro car. For most people the extended range is only needed very occasionally but you have to carry the ICE system the whole time.
Depending on the compromises you're willing to make, a small gas engine that doesn't run very often isn't a lot of excess weight, and it's not going to make heat, vibration, and exhaust except when it's running ... which could be 30 minutes a month (to keep it healthy) plus whenever you actually need the extended range.
Since it's just for range extension, you could maybe stuff the engine in the rear, so you don't have to pipe exhaust under the whole car. Although then you probably want to pipe coolant to a radiator in the front and have to protect that piping... but at least it's only coolant hot and not exhaust hot. The engine noise would be away from the driver at least.
You said you didn't want the heat of a gas car, but you might choose to run it a little bit more in the cold to help warm the interior on cold days (especially at startup).
Potentially, but not really likely, you could try to make it modular-ish... attach it when you need it, leave it in your garage otherwise. But I think it's going to be too heavy ... I have a 7200 W portable generator which is roughly half of what an EV uses at cruising speeds, and it takes two people to lift it. Automotive engineers do amazing things, but I don't think they're getting twice the power and less weight and easier to move...
The problem is all of that is competing with "just charge it". Over the lifetime of the vehicle now, whatever route you have that is underserved by chargers is likely to gain chargers soon.
the bmw i3 REx was this. it didn't sell well, for a variety of reasons.
The original/first BMW i3 (2013) was like this, full battery electric (with an admittedly small battery 80-160 miles range depending on model), with an "range extender" engine.
Personally I'm a big fan of the EREV (which only drives an alternator, rather than a PHEV which drives the wheels directly) due to the simpler mechanical design - however I'm not sure if it's a personal preference. I feel even a fairly small 30kw (40hp?) would make a huge difference to the utility of the vehicle, while still being small and economical.
You may be interested to read / watch videos of Audi's RS Q e-tron they raced in the Dakar Rally and even won with this type of powertrain - https://en.wikipedia.org/wiki/Audi_RS_Q_e-tron
The above comment’s video explains why.
You lose energy converting the the gas power to electrical power to mechanical power. Constant RPM doesn’t matter as much as you think.
There were several of them: the first and second generations of Chevy Volt, Fisker Karma, BMW i3, and a couple of Chinese brands.
They're less efficient than parallel hybrids at high speeds (on a freeway). And you also need a fairly sizeable engine to keep up with the consumption at freeway speed, so at this point you might as well just throw in a planetary gearbox.
The Chevy Volt (and it's predecessor the GM 2-mode hybrid, and the Allison power-split hybrid) was a work of art. It is fundamentally a planetary gearbox, with 2 motor-generators.
In ICE mode, under 35 MPH, it worked as a series hybrid. Above 35, the engine mechanically connected to the wheels. One motor-gen extracted power and fed it to the other, acting as a CVT in parallel. This provided the ratio changes needed for the small engine.
It was way too complicated and expensive the two times they tried it (2008, then the Volt). It was successful and lives on to this day in its original application: city buses.
Planetary gear plus 2 motor-generators is 'Toyota Synergy Drive' and also used by Ford and Stellantis in some hybrid models. At least the Ford C-Max and Chrysler Pacifica hybrids use this style drive train. I'm not on top of all the hybrids, but I'd guess if 4 car makers do it, there's others to be found.
It makes a lot of sense, works well, and is very durable... as long as Ford didn't forget to heat treat a bearing or whatever they messed up in early C-Maxes.
I had a 2012 Chevy Volt. It was indeed a delightful car!
But I believe that the series mode was a mistake. The later versions of Volts removed it entirely, improving the fuel economy.
> It was way too complicated and expensive the two times they tried it (2008, then the Volt). It was successful and lives on to this day in its original application: city buses.
I don't think that it was too complicated. Hybrids are using essentially the same system, except that they have a smaller battery and less powerful electric motors.
bmw I3s were this type of hybrid as far as I remember.
the ICE extender was an option.
And the range extender was underpowered. Drive up a hill on a freeway at 70 mph and the battery would deplete and the car would slow down to 25 mph which was the fastest the range extender could make it go up a gentle incline.
It's dangerous to do 25 mph on a freeway... There are some roads I'm too scared to drive my i3 on now.
If you pulled over to let it recharge, it wouldn't do so, since the range extender refuses to run at full throttle when the car isn't moving fast (perhaps no cooling fan??)
Yup, my friends had one and loved it despite the... unique styling.
They live in the Puget Sound area, and both work at the same place. It worked out to where they could do their commute, and ordinary errands entirely on battery, and only needed the range extender if they were going into downtown Seattle or on a road trip or such.
Theoretically couldn't you take an electric car and put an off-the-shelf generator in your frunk and wire it up to charge the battery as you drive?
My PHEV won't 'start' while plugged in. You'd need to bypass the usual charger mechanisms, and then the computer seems likely to get mad...
A minor inconvenience compared to the thousands of charger cables and wall boxes that would charge driving the cars for a very small moment.
>>and put an off-the-shelf generator
Even my really underpowered PHEV has a 65kW electric motor. No "off the shelf generator" can generate 65kW, in fact it would be a huge unit that could.
We could of course say - well, it doesn't need to match peak usage, it just has to charge the battery faster than it depletes - you still probably need around 20kW for steady motorway driving, and that's a pretty hefty generator.
I don't think you need to have it match the depletion rate. Even at say 10kW you'd doubling the effective range. The point is people want to be able to use their car for that twice a year road trip, or drive to the inlaws for Thanksgiving. If you can attach something that extends the range for these occasion then that's probably enough.
Furthermore, the generator can run 24/7, but realistically you will at most drive ~6 hours a day. So for a leisurely road-trip this may be enough to avoid needing stops at charging stations
20kw would be enough to maintain the battery though? So you could halve that and 'only' double the range in the worst case.
Already a big push with this. They call them EREV now, extended range electric vehicles.
You mean like a BMW i3 with a range extender? Little two-cylinder petrol that just spins a genny.
They work, they're not terribly efficient in terms of converting fuel to distance travelled, and really batteries are getting so good these days there's little point any more.
Isn’t that how diesel trains operate?
Honda's current hybrid system and this e-POWER both work this way mostly
The concept is called range extenders, and the video does explain why it’s one of those false great ideas and every production vehicle has failed: EVs with range extenders are at best bad EVs and at worst terrible hybrids.
Edison in Canada is doing diesel electric hybrid trucks
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Aka EREV, thats becoming majority of “PHEVs” now.
per wikipedia
>From mid-2025, EREV sales in China declined year-on-year for several consecutive months
just in time as Toyota decided to go all EREV https://electrek.co/2026/09/21/toyota-joins-extended-range-e...
>Toyota will make the EREV in China, aiming to produce 200,000 units in 2027. In 2028, production is expected to rise to around 400,000 units.
Hilarious, from promoting fail hydrogen fuel cells and producing anti EV propaganda to chasing fading trends. Anything but real EVs.
Yes, this is an "Extended-range electric vehicle" or EREV
> an electric vehicle fitted with a fuel-powered internal combustion engine, acting as a range extender that drives a generator
https://en.wikipedia.org/wiki/Extended-range_electric_vehicl...