Does it produce more low end torque verses a traditional gasoline combustion engine? If not then why is it better suited for electrical generation? Is it more efficient with less load?
The article mostly makes it sound like Mazda just loves the wankle and wants to find any possibly way to bring it back - even though it has “high” emissions… so coupling it with a hybrid electric motor makes it happen..
That can’t be the whole story?
I used to own the first gen electric i3 with its tiny range. I didn’t wish to have the hybrid ICE version to drive further, but I did wish for more electric range and more fast chargers along the road.
Nowadays, I have a cheaper car with a lot more range, almost 4 times more in real life conditions, and plenty of fast chargers everywhere. I don’t see why I would bother with an ICE. It makes no sense for me.
It’s because I live around Oslo in Norway, a place where it’s the age of electric cars.
I think ICE for cars has a very limited future in the age of electric cars. I see it reserved for specific applications where the energy density is a must, and some car enthusiasts activities.
Hybrids are some kind of temporary solutions for places where the EV infrastructure aren’t good enough yet. Once the infrastructure is good enough, some people will still buy ICE for a little while as they are unsure, but most switch to full electric eventually. At least that what happened around Oslo and happens now in the country side of Norway.
I have never understood why the Volt Series Hybrid idea never took off. It is more efficient to turn gasoline into electricity and then drive the car with that than to directly connect the engine to the wheels. Is it perhaps that the cost involved is just too much more than a plugin hybrid to make the small extra fuel savings worth it?
It's worth mentioning that serial hybrids, like the BMW i3 rx, might not be able to drive on the freeway on the output of their generator. That's why it's a "range extender" - at some point you have to pull over and charge.
EDIT: this is a big secret that none of the marketing materials (want to) make clear.
I'm uncertain the output of the wankel, but maybe with its power-to-weight it might get closer to being able to drive on gasoline in a self-sufficient way.
I was always impressed by this engine in my childhood, but it never really caught on. Here is a variation I've seen on the internet, i'm not sure how practible it would be. https://arstechnica.com/cars/2023/11/this-inside-out-design-...
Mazda and Toyota formed an alliance to share technologies to fill gaps they each had. I'm guessing this is fruit of that partnership.
The problem with the Wankel is and has always been apex seals. You need to rebuild it at least once during a vehicle lifetime. I would not say it is safe from this fate, even with modern seals and a hybrid application.
The fortnine video about this type of engine is quite interesting:https://youtu.be/-3HBAvkc4a0?feature=shared Mazda might be one company with the expertise to make it work. The range extender, not directly driving wheels, can work in its optimum temperature, rpm and on a pretty constant load. The ability to work with multiple types of fuel adds to its versatility as a range extender. Since Mazda has alliances with other Japanese car makers, if it is indeed a good proposition, I reckon it would appear on other Japanese cars too, and maybe in BMW as well.
Almost feel bad for GM, the article did not mention the Volt when talking about series hybrids. But I guess it is a Japan-focused news source.
I like the LiquidPiston engine technology as an inverse Wankel engine. A lot more efficient.
A good article.
It barely addresses the elephant in the room however: The Toyota Prius and its Atkinson engine.
The Atkinson engine is 99% the same as a regular engine (aka: Otto cycle), except the timing is different. Instead of closing the valves when the piston+cylinder is full of gasoline+air mix... the Atkinson engine waits a bit and "leaks" some gasoline+air back out before closing the intake valve, effectively burning only 70% of the fuel, but getting maybe 85%+ of the power of a regular Otto-cycle engine. Its a simple and cheap tweak to a traditional engine that grossly improves efficiency (but at huge costs to low-end torque).
Basically, any regular ol' carmaker who is mass producing Otto cycle / regular ICE engines can easily tune their piston timing to be an Atkinson engine instead. I believe Toyota even has computerized controls today that switches between efficient Atkinson (lower-power but higher efficiency) modes and powerful Otto cycle (higher power but lower efficiency) modes, though this control isn't really used too often in practice.
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This article makes a good point that Mazda has a culture of this... rotary engine. It does compare it (somewhat unfairly) to the Atkinson engine though (inside the Prius and RAV4), I don't think anyone expects any traditional engine (Otto or Rotary) to keep up with Atkinson Engine efficiency.
Its a good try however. But it does raise the question of what benefits can this rotary engine give over other engine types.
What was the purpose of using the rotary engine in the first place, for ICE cars? From the comments it seems it's maybe lighter for a given power output. Is that it, other than just the novelty of it?
> NSU and Mazda are the only manufacturers ever to have mass-produced rotary engine vehicles.
Not quite true. Suzuki also made and sold a rotary engined vehicle--specifically the RE5 motorcycle.
One of the cool things about this engine is that it can run on hydrogen with minimal modifications. Not sure if the article mentions this, I don't have time to read it now. But that could make it more interesting when renewable hydrogen becomes common (right now it's not)
I think I heard this pitched by Neil Diamond 15 years ago. He had an f body or similar old big body car from the early 80 retrofitted with a rotary engine charging the battery… I’m so glad to hear this finally making production.
I have so many bad memories from this engine. I finally brought them to court to win. But all this to say Mazda has been out of the game so long living on dreams with this engine.
The mid-90s RX-7 was sexy as hell.
But the RX-8 just wasn't.
A cool engine still needs to be wrapped in a car that people want to drive.
The MX-30 doesn't quite fit the bill... just seems so mundane to look at.
Can you buy it as an EV and then drop in the generator later? It makes a big difference for registration in some places.
Instead of a Wankel, why not use a small custom turbogenerator, like the APU in aircraft?
> Despite all this, though, the MX-30 R-EV still falls somewhat short, with a catalog fuel efficiency of 15.4 kilometers per liter (as measured in WLTC mode). With no similar vehicles on the market, like-for-like comparison is not possible, although the Toyota RAV4 plug-in hybrid gets 22.2 km/l, while the Prius plug-in hybrid gets 26.0 km/l. The MX-30 R-EV is clearly inferior in terms of its fuel economy.
That's because the engine serves an entirely different purpose. The Prius plug-in hybrid is a 13.6kWh battery mated to a regular engine. The MX-30 R-EV is a 17.8 kWh battery mated to a tiny ultralight emergency range extender.
As to similar designed cars, um, hello, the BMW I3 Hybrid? Exactly the same design.
The failing of the MX-30 R-EV is that its battery size is pathetically small for what amounts to an EV with a range extender. It is an embarrassment.
Is the rotary better or worst with pollution ?
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I've always seen rotary engines as one of the best examples of a particular approach to design that solves something very elegantly but relies too much on one critical component where all the pressure of the design is applied. In the case of a rotary engine, it's the apex seals.
They're a great warning for designers/architects/engineers to not get too enamored with the elegance of a system if parts of it are not yet completely solved. It's so easy when designing to try to shove aside some complex problem and say you'll solve it later, or play some shell game where every time you hit some hard to solve problem you wind up shuffling it around to someplace else [1], but that kind of instinct ultimately leads to unworkable things in practice.
[1]: 'we'll solve the seals problem later.. maybe materials has an answer' or 'just add oil in the mix to protect the seals there, we'll solve emissions later'