Mazda Rotary engine returning in 2020...but not for direct power.

mmcartalk

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The long-awaited return of the Mazda rotary will apparently come next year...but not as a direct power plant. Instead, the plans are, for now, to use it as a range-extender for EVs and to keep the batteries charged. To me, that makes at least some sense, given the rotary's compact size (it can fit almost anywhere), its marked lack of torque at low speeds, and its tendency to use both oil and gas. Might as well use it, instead, just periodically, to keep the electric motor going.


http://www.thedrive.com/news/23970/mazda-announces-the-return-of-the-rotary-as-an-ev-range-extender

Mazda has been teasing the topic for quite some time, publishing various patents and ideas on how it could revive its defunct Wankel rotary engine, but now, it's officially official: the Japanese automaker will bring back its famous rotary engine in 2020.

Before you celebrate, we should note that the revived rotary won't be used in the traditional sense of powering a car, at least not yet. Instead, Mazda plans to raise its iconic powerplant from the grave to give it new life as a method to extend the range on its upcoming electric cars.

The details of Mazda's grand scheme were revealed on Tuesday as the automaker published information pertaining to its plans for electrifications. Like many manufacturers, Mazda has become infatuated with the idea of diving head-first into electrifying its entire lineup of vehicles but despite its existing electrifying partnership with Toyota, it doesn't quite have the footing in the battery market like certain other automakers.


Using the rotary engine as a supplementary form of electric charging, vehicles will be able to effectively extend their range without plugging in to charge. Essentially, Mazda is trusting the rotary engine to utilize its small, lightweight form factor and generally quiet operation to make electrified driving undisruptive to vehicle owners.

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An accessory rotary engine drives range-extending generator

By 2030, Mazda expects its entire lineup to be electrified in some way, though it plans on Battery Electric Vehicles (BEVs) making up only five percent of its fleet. Instead, the automaker is heavily banking on hybridization of its vehicles, prioritizing the internal combustion engine with supplementary electric drive systems.

This approach is very Mazda-like, as the company has long said its approach to automotive design is human-centric. The automaker, though not nearly as conservative with its technologies as Toyota, has been historically withdrawn from changes to the typical stop-and-go of automaking. Perhaps Mazda is afraid to burden the consumer with the potential inconvenience of waiting for a vehicle to charge, or maybe battery technology simply isn't its forte.

Regardless of its reasoning on the rotary's return or lack of enthusiast-focused application, we're humbled to know that Mazda is welcoming the technology back with open arms. Now it's time to anxiously await the launch of the platform in 2020 and hope that it leads to Mazda using the rotary in other applications.
 

spwolf

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there was some PR news few months ago that Toyota will use Mazda's rotary engine as range extender in their vehicle... This might be limited to new EV coming from new Plant in USA, JV between Mazda and Toyota, or it might be wide spread.
 

ssun30

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Well a rotary sustainer could be a stop gap solution before they commercialize the free-piston linear generator. Compactness really is key here.
 

ssun30

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In short what you need to know:
ロータリー = rotary/Wankel engine. He was mentioning Mazda reserved space to package in a rotary range extender, which we know has been in the works for a while.
The CX-30 e-TPV has a 33.5 kWh battery powering a 105 kW motor. There is no mentioning of range. But he wrote that Norway has an extensive charging network so such a moderate battery size may still be sufficient. The size makes sense for a USDM EREV. EPA requires EREVs to have at least 50% of usable energy from the battery only. So in this case the range-extended CX-30 will have up to 67 kWh of energy, which is standard for this segment.
The Acoustic Vehicle Alerting System mimics two overlapping Inline-3 engines which makes it sound like a weird V6.

Other comments are just what you expect from any EV review. Praise about improved handling and ride quality due to lower center of gravity and extra weight in the chassis, quietness and smoothness etc.
 

Sulu

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I found some of the analysis in the following article interesting.
  1. Battery capacity, at 35.5 kWh, is on the low side (good enough for approximately 200 km / 125 miles), but that may be the ideal capacity, so the theory goes: Few people require the 100 kWh needed for 500 km / 310 miles of range; and that extra 60+ kWh is a waste. If more EV makers used the ideal capacity of 30 to 40 kWh, instead of 100+ kWh, 3 EVs could be placed on the roads rather than 1 large-energy capacity EV.
  2. A range-extender will be available, and this being a Mazda, it will be a Wankel rotary engine. Wankels are not known to be efficient as a primary power source but in a serial-hybrid vehicle, where it would be running at constant rpm, it should be very efficient, both in size and fuel efficiency.

Motor Mouth: Is Mazda's e-TPV the perfect electric vehicle?
Mazda bursts onto the EV scene with a car with zero emissions, multiple energy sources and fine handling to boot

OSLO, Norway — As electric vehicle powerhouses go, Mazda is an extremely unlikely candidate. Heretofore resolutely dedicated to internal combustion – for such a relatively small manufacturer, they’ve managed an incredible number of ICE breakthroughs – the Zoom-Zoom company has barely ventured into electric, and is one of the few mainstream automakers selling neither electric vehicle nor hybrid of any kind in North America.

And yet, not five minutes into the presentation from Mazda’s head of vehicle development and product planning, Hiroyuki Matsumoto, in the Amerikalinjen hotel in Oslo, Norway, I knew I was looking at exactly the electric vehicle I would be designing, were I still using my now-45-year-old engineering degree.

Let’s start with the basics. Mazda has calculated the optimal battery size is 35.5 kilowatt-hours. Now, that may seem an awfully precise and, more importantly, small rating for an EV’s battery, but thanks to some efficiencies it was unwilling to volunteer at this juncture – the final spec of the company’s first electric car won’t be released until this year’s Tokyo Motor Show – that’s good enough for around 200 kilometres of inner-city driving.

Why not go for a Tesla-like 500 kilometres of range, you ask? After all, that’s the main battlefield these days for electric vehicle supremacy, automakers competing to cram as many lithium-ions into their increasingly expensive EVs that they might alleviate our range anxieties.

Well, there are two reasons. The first – and this has been proclaimed by every EV-maker from Tesla to Toyota, not to mention pretty much every amateur commenter on Motor Mouth – people seldom use anywhere near the required 100 kWh needed to guarantee 500 clicks of autonomy. And fewer kilowatt-hours means less weight, reduced cost and dramatically better handling in any EV.

It is also, according to an increasing number of voices, including electrification-powerhouse Toyota, an inefficient use of lithium. The theory being espoused is that increasing the size of a car’s battery brings diminishing returns in terms of greenhouse gas reduction. Essentially, go the calculations, putting one kWh into 100 hybrids will reduce more CO2 – 100 times 40 per cent, or the equivalent of 40 purely ICE cars – than ladling 100 kWh into one Tesla, which is only equivalent to getting one ICE-powered vehicle off the road.

According to the projections I have seen, the break-even point – more accurately, the size of battery beyond which there is very little benefit in CO2 reduction – is somewhere between 30 and 40 kWh, pretty much in line with Mazda’s determination.

Of course, that means the basic e-TPV – electric-Technology Prove-out Vehicle – is largely an urban runabout. Oh, its 200-or-so-kilometre range will be just fine for suburban forays and the like that will almost assuredly cover most consumers’ daily drives, but it isn’t the range-monster that is going to get someone across the Prairies on a cross-Canada excursion. That’s why Mazda’s production EV, due late in 2020, will offer —

A range extender. And not just any range extender, but a rotary-powered generator.

Now, I don’t think I need to remind anyone reading Driving.ca that “Mazda” and “rotary” are fairly synonymously entwined, the company being the last automaker to produce a rotary-engined car, the 2012 RX-8, for North American consumption. What you may not know is that Wankel engines are extremely efficient in both size – the U.S. Defense department has experimented with a three-kW rotary generator small enough to fit in a backpack – and fuel consumption.

(Though greedy when revved to their extremely high redline, they are more efficient than piston engines when maintaining a constant rpm).

In other words, their small size – important when you’re trying to stuff 355 volts of battery, an inverter and a range extender into a compact crossover – serves a range-extended EV perfectly.
Mazda’s electric-Technology Prove-out Vehicle Mazda

But, so far, the e-TPV sounds a lot like a budget version of the Polestar 1, an interesting Tesla alternative that, while both entertaining and ground-breaking, is hardly perfect. The Mazda, however, gets closer to that perfection when Matsumoto announces the TPV’s rotary range extender can run on hydrogen. That’s right: Zero-emissions, greenhouse gas-friendly hydrogen.

For all you BEV proponents out there ready to decry any hybrid’s lack of purity, that means, save for a few hydrocarbons that squeak past a rotor seal – the equivalent of a piston engine’s rings – Mazda’s range-extended rotary would be as emissions-free as any ludicrous Tesla. And, in fact, Mazda already has experience with hydrogen-fueled rotaries, having produced a fleet of H2-powered RX-8s for Norway’s “hydrogen highway” experiment (supposedly King Harald V, who kicked off the program, was a big fan).

“But,” I can already hear Tesla fans screaming, “there is no hydrogen highway!” Putting aside the fact hydrogen stations are finally starting to pop up everywhere, Mazda’s last little trick is that the rotary could be – and, to be clear, is not yet – dual-powered. That is, future Mazda range-extended EVs could run on both gasoline and hydrogen. And, here again, Mazda has already experimented with dual-fuel hydrogen/gasoline rotaries, having produced the RX-8 RE in 2003.

So, at some point in the now-much-nearer future, I will be able to drive a Mazda that will fulfill all my daily driving needs emissions-free via a convenient charging port at home, drive in between cities without poisoning the atmosphere when H2 refueling stations are available and then, if I find hydrogen not available in some far-flung rural location, I can squeak by with a dash of gasoline.

In fact, for those still trumpeting Tesla superiority, hear this: A dual-fuel, range-extended Mazda means that, in the best of circumstances, I will have completely eliminated my tailpipe carbon footprint. In a worst-case scenario, my automotive CO2 production will have been reduced by some 80 per cent.

And all this without having to visit one slower-than-molasses, my-God-the-lineups-will-be-worse-than-the-1973-oil-crisis Supercharger station.

That’s what I call the perfect electric vehicle.

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