Good! Competition is good!

the tiny rotary engine would be easier to package.

and they have demonstrated the rotary engine fueled by hydrogen.

but the RX-8 (the only rotary-engined new car being sold today), has exceptionally poor fuel efficiency. worse than it's traditionally-engined counterparts, despite being a lighter vehicle.

RX-8: 18 mpg 3050 lbs
350Z: 20 mpg 3600 lbs

is this an inherent efficiency problem for rotary engines?

Rotaries burn a lot of oil too, afaik. But I guess if you have a decent battery range and the rotary only kicks in a few times a month, the lower weight might be worth it.

You have to carry that engine all the time even when it's off, so it matters.

If they make this vehicle a PHEV I may just drool all the way to the dealership for my first car ownership in years.

A Wankel rotary engine as a generator and all electric drive :D

A Wankel rotary engine to power a battery pack is a good idea.

The engine should be run occasionally and only in specified RPM ranges; at specified RPM bands Wankel engines can be very efficient and Wankel engines have much less weight.

AS for the oil burning -- I believe that there have been seal tests to reduce the oil consumption of Wankel engines but the could not find seal that worked well under all engine running conditions. They may finally be able to put that research to use with a Wankel engine working as a generator.

The more companies get involved, the faster adoption and improvement will be. Yay!

This is interesting. The Wankel has always been an engine in search of a purpose. Mazda has kept using it despite its dendency to be inefficient and unreliable, but in this case both may be offset by the contribution of its low mass to the vehicle's overall efficiency and its infrequent use.

Further, it may have potential to be more efficient and reliable in this application than it is in the RX-8, as the RX-8 is a sports car, so focus on the engine tuning is on making power. As a range extender it wouldn't need to make nearly as much power, so a lot of performance could be sacrificed for the sake of efficiency and reliability.

I believe the rotary design at a set rpm is more efficient than a piston engine, and the oil burning was more of a high-rpm issue. So I'm THINKING if it were developed for a generator, it might have some good specs!

Indeed, the seal problem that faces the wankel is an RPM dependent deal which is really a shame: the near perfect balance of the wankel allows it to rev very high very easily.

Here is what I see for the wankel PHEV: a 400cc twin rotor turbocharged unit. The turbo will be setup to provide full boost pressure under 3000rpm. They will restrict the engines to about 3000rpm and run it at a high load (the crank will easily be able to take it). Aluminum construction. The whole thing might make 70hp and weigh ~100lbs.

NICE! GO MAZDA GO!

Actually, I'm certain it would be a MUCH smaller displacement than the RX-8, and thus negate the concerns about MPG.

Mazda has supplied several small displacement Wankel engines for decades in the domestic market in Japan, for everything from utility carts to forklifts.

It in fact would most likely have a relatively light load, turning the generator, and also, probably not directly, but through gearing that would improve the RPM demands on the engine. Frankly, I think it's a much better choice for this kind of application than the traditional straight or V cylinder configurations.

A key issue I have with hybrids is replacement battery cost. Batteries have a finite life as well as a limited amount of times they can be charged and will therefore eventually have to be replaced. Toyota recognized this when they made the Prius (that's why the engine is the primary drive) All the conversions to PHEV and circuit changes do is increase battery usage. (Did I mention that these batteries aren't cheap? Think laptop battery times 100+ for the whole car) Top line batteries store only about 1% as much energy as gasoline pound for pound. Yes the electric drive can use it more efficiently than a gas engine so the battery disadvantage is more like a factor of 30. For the same range you can carry 70 pounds of gas or 2100 pounds of batteries. Batteries are heavier than gas per cubic unit and so you only need about ten times the amount of space for the energy equivalent of 11 ¼ gallons of gas.

Cars need to get lighter (carbon fiber anyone?) and more aerodynamic so that the energy needed to move them is reduced.
Putting glorified laptop batteries in a conventionally constructed (read: steel) automobile isn't the answer. Scooters and motorcycles get decent MPG numbers not because of some magic engine, but because they don't weigh nearly as much as a car. Some could argue that pound for pound they're less efficient than a car.

So, in my view, I'll skip the Volt and the Mazda Wankel platform and concentrate on cars like the Honda Fit for those occasions when we need something more than our bicycles, city buses, and Amtrak can provide.

If the Zebra battery were mass produced the costs could be reduced to about $2,000 per unit. This would be a very good introduction battery for electric cars despite its limitations.

A mature electric car market would increase research on better batteries.

Having this Mazda working on batteries, with or without the range extender Wankel, is a great idea. I hope it gets into production very very soon.

"A key issue I have with hybrids is replacement battery cost. Batteries
have a finite life as well as a limited amount of times they can be charged
and will therefore eventually have to be replaced"

Batteries in hybrids are tested for the life of the car. Some cabs have put over 300,000 miles on Priuses without problems.

That's why they never charge and discharge them completely, to extend life. Shouldn't be a problem.

Anon 8/31 11:08PM said:

"Batteries in hybrids are tested for the life of the car. Some cabs have put over 300,000 miles on Priuses without problems.

That's why they never charge and discharge them completely, to extend life. Shouldn't be a problem."

I'm sure you believe that oh one who refuses to identify thyself on the internet, but it ain't necessarily so.

Rechargeable batteries work via a chemical reaction. During charging, the positive active material is oxidized, producing electrons, and the negative material is reduced, consuming electrons. These electrons constitute the current flow in the external circuit. The electrolyte may serve as a simple buffer for ion flow between the electrodes, as in lithium-ion and nickel-cadmium cells, or it may be an active participant in the electrochemical reaction, as in lead-acid cells.

I'm sure nobody has ever replaced a car battery or a laptop battery in their lives..... These current gen battery packs are nothing more than a bunch of laptop batteries wired together.

Battery packs and extra generators are heavy and cost a lot. I would rather have a e85 powerd ultra light car with decent cargo room.

Really Rob?

Do you honestly know how crappy corn ethanol is in reality? That it actually takes oil to produce it in the form of fertilizer? That it's a primary reason why the prices of breads and grain products have been jacked up lately due to farmers switching from wheat to the govt's greenwashed sweetheart corn? That it barely breaks even on the amount of energy it produces versus the energy required to make it in the first place (most of that coming from coal). No, E85 isn't the devil, (to borrow a character from Family Guy) it's the SuperDevil.