A.k.a. Atkinson-cycle (1882): https://en.wikipedia.org/wiki/Atkinson_cycle
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.
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
Disclosure: I have a small investment in them.
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...
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...
https://www.motortrend.com/features/what-is-an-erev-extended...
the ICE extender was an option.
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.
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.
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.
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.
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.
And yes the Atkinson cycle helps
For comparison, the full classic gasoline engine with manual gearbox consumes less gasoline than the e-Power one. This is just some pure greenwashing, that isn't even explained at car dealerships and people can't say anything about it, when you ask for information.
Works like (?) an EV, it isn't an EV.
You surely mean that it is not recognized as plug-in hybrid vehicle.
tl;dw: constant RPM and a weird stroke geometry where the power stroke is longer than the other strokes to extract more energy from the expanding gasses.