Why are Mazda persisting with the Rotary Wankel engine?

[RayTay]

Toyota, with about 15 others have been doing R&D on the free-piston linear generator for range-extender applications. R&D had been ongoing in some places for 15 years. Toyota made a prototype and issued details and drawings. No one has cracked it yet. It is clear Toyota are turning to the rotary engine as a range extender teaming up with Mazda.

The latest tweak to the Prius now gives about 30 miles on a full battery charge, now using Lith batteries, then the large engine, in physical size and displacement, will kick in to drive the car via the power splitter (this is not an in-line transmission as we know it) and recharge the batteries as well. The car is driven via electric traction then internal combustion traction. It can also be driven a combination of both via the power spitter.

The whole bulky Prius setup is now 20 years old and was superb for its time when battery technology was less than what we have now. Toyota now need a major step up. The rotary will given them a true generator, not driving the car directly via the power splitter. Toyota are aware that the rotary is very efficient at constant speeds and matches the requirements for a part time range-extender.

http://www.caradvice.com.au/500011/mazda-to-introd...

http://www.digitaltrends.com/cars/mazda-electric-c...

https://www.ft.com/content/fec96dfe-8bd4-11e6-8aa5...

https://www.ft.com/content/149ca550-7e30-11e5-a1fe...

Edited by RayTay on Thursday 15th December 14:20

[Mave]

RayTay said:

The whole bulky Prius setup is now 20 years old and was superb for its time when battery technology was less than what we have now. Toyota now need a major step up. The rotary will given them a true generator, not driving the car directly via the power splitter. Toyota are aware that the rotary is very efficient at constant speeds and matches the requirements for a part time range-extender.

http://www.digitaltrends.com/cars/mazda-electric-c...

https://www.ft.com/content/fec96dfe-8bd4-11e6-8aa5...

I can't open the second article - but the first makes no mention of the rotary being very efficient at constant speeds.

[Krikkit]

Mave said:

RayTay said:

The whole bulky Prius setup is now 20 years old and was superb for its time when battery technology was less than what we have now. Toyota now need a major step up. The rotary will given them a true generator, not driving the car directly via the power splitter. Toyota are aware that the rotary is very efficient at constant speeds and matches the requirements for a part time range-extender.

http://www.digitaltrends.com/cars/mazda-electric-c...

https://www.ft.com/content/fec96dfe-8bd4-11e6-8aa5...

I can't open the second article - but the first makes no mention of the rotary being very efficient at constant speeds.

But, if you follow it through to the Mazda 2 EV/Range extender that they look at, the claimed max range is 600km with a full charge and 20L of fuel... That's pretty good!

[RayTay]

Krikkit said:

But, if you follow it through to the Mazda 2 EV/Range extender that they look at, the claimed max range is 600km with a full charge and 20L of fuel... That's pretty good!

That is very good indeed. Here are journos driving a Mazda 2 prototype three years ago. The are impressed. They say what will stop it advancing is the price of the cars. Things have moved on. What will promote them is that Paris, Madrid, Mexico City, and Athens, will be free of diesel vehicles by 2025. London and others will follow suit. Many will also be ultra low emissions. London has congestion charges, hence why lots of hybrids are seen in the city because they do not pay congestion charges and pay zero to low road tax.
http://www.drive.com.au/new-car-reviews/mazda2-ev-...

As battery technology moves on giving greater range, the range-extender will cut in far less. Even if a range-extender is slightly below par in efficiency, for the few times it cuts in it doesn't matter too much when calculating the energy use of the vehicle over a year. Makers ideally want physically small and quiet range-extenders for superior packaging.

https://www.ft.com/content/149ca550-7e30-11e5-a1fe...

Edited by RayTay on Thursday 22 December 15:54

[Mave]

Krikkit said:

But, if you follow it through to the Mazda 2 EV/Range extender that they look at, the claimed max range is 600km with a full charge and 20L of fuel... That's pretty good!

Sure, but that doesn't tell you anything about the efficiencies of the constituent parts.

[Mr2Mike]

Krikkit said:

But, if you follow it through to the Mazda 2 EV/Range extender that they look at, the claimed max range is 600km with a full charge and 20L of fuel... That's pretty good!

The range extender engine makes less than 30bhp. Performance with low battery charge may not be too impressive in something weighing ~1350kg.

[RayTay]

Mr2Mike said:

The range extender engine makes less than 30bhp. Performance with low battery charge may not be too impressive in something weighing ~1350kg.

It was actually a prototype from 3 years ago. Those who test drove it were impressed enough even when the battery was run down. Mazda deliberately ran down the battery for them to drive. The finished article will be nothing like that car. But it does show the way ahead. The recent link up with Toyota should bring out something interesting.

Edited by RayTay on Thursday 22 December 15:56

[RayTay]

Appears to be progress on the rotary/hybrid front:

New Mazda patents:
http://www.thedrive.com/sheetmetal/8618/mazda-pate...

https://uk.motor1.com/news/140271/mazda-rotary-pos...

https://www.digitaltrends.com/cars/mazda-wankel-ra...

[RayTay]

In 2019 Mazda will introduce a rotary hybrid car. 2020 is their centenary so a rotary must be on the sale list.
https://www.motoring.com.au/mazda3-hybrid-still-no...

[GSX]

Yes I know this is a year old but I was Googling stuff and started reading...not all 39 pages but a few..

Ive got an "8" outside, aswell as a 530d (gearbox needed), Golf 1.9tdi and Fiesta 1.4 Zetec (clutch needed), they all have their character and don't know what I prefer truth be told. When in the 8 as I was today it kinda makes me feel good but at the same a bit of flash dick. When in the Golf and Fiesta I obviously blend in, 530d I don't know yet apart from another old BM otr to blend in if/when it gets fixed.


As for the 39 page debate on the rotary, my god and I certainly don't have anything worth saying to contribute apart from saying - yes I know a lot bang on about it's mpg, it is what it is, no you don't have a sports/sporty car and expect 40odd but I too would like a bit more than 15ish and or course cheaper tax than the 555 (well nearly 6 as I pay up)…..but hey ho.


And as we all know Mazda dropped the rotary back in 2010,11 or 12 I think I guess they couldn't do anything else with it to get better mpg/emissions for the Eurocrap/tree huggers. But reading Ray's posts above...oh well..

Edited by GSX on Monday 22 October 01:13

[GSX]

Yes I know this is a year old but I was Googling stuff and started reading...not all 39 pages but a few..

Ive got an "8" outside, aswell as a 530d (gearbox needed), Golf 1.9tdi and Fiesta 1.4 Zetec (clutch needed), they all have their character and don't know what I prefer truth be told. When in the 8 as I was today it kinda makes me feel good but at the same a bit of flash dick. When in the Golf and Fiesta I obviously blend in, 530d I don't know yet apart from another old BM otr to blend in if/when it gets fixed.


As for the 39 page debate on the rotary, my god and I certainly don't have anything worth saying to contribute apart from saying - yes I know a lot bang on about it's mpg, it is what it is, no you don't have a sports/sporty car and expect 40odd but I too would like a bit more than 15ish and or course cheaper tax than the 555 (well nearly 6 as I pay up)…..but hey ho.


And as we all know Mazda dropped the rotary back in 2010,11 or 12 I think I guess they couldn't do anything else with it to get better mpg/emissions for the Eurocrap/tree huggers. But reading Ray's posts above...oh well..

Edited by GSX on Monday 22 October 01:21

[RayTay]

Mazda has confirmed that it will launch its first two electrified cars in 2020: a full battery EV and a rotary-engined hybrid range extender.
https://www.autocar.co.uk/car-news/motor-shows-par...

The engine will also “burn liquefied petroleum gas and provide a source of electricity in emergencies." Handy indeed.
https://www.autoexpress.co.uk/mazda/98958/mazda-co...

Edited by RayTay on Thursday 6th December 18:13

[RayTay]

Nice video on a hydrogen powered rotary:
https://www.youtube.com/watch?v=U-n5L0cXcpg

[RayTay]

23% greater fuel efficiency using hydrogen fuel rather than gasoline, with near zero emissions.
https://www.cder.dz/A2H2/Medias/Download/Proc%20PD...

Four-stroke reciprocating piston engines are poorly suited for conversion to hydrogen fuel. The hydrogen/air fuel mix can misfire on hot parts of the engine like the exhaust valve and spark plugs, as all four stroke operations occur in the same chamber.

Hydrogen/air fuel mixtures are quicker to ignite with a faster burning rate than gasoline. In a rotary engine each power pulse of the Otto cycle occurs in different chambers. The rotary has no exhaust valves that may remain hot that sometimes give backfiring in piston engines. The rotaries intake chamber is separated from the combustion chamber, keeping the air/fuel mixture away hot spots. All this lends the rotary engine highly suitable for the use of hydrogen without pre-ignition or backfire.

As hydrogen/air fuel mixtures are quicker to ignite than petrol mixtures with a high burning (flash) rate, resulting in all the fuel being burnt with no unburnt fuel being ejected into the exhaust stream as is the case using petrol fuel in rotary engines. Emissions are near zero, even with oil lubrication of apex seals. All these points lends the wankel engine ideal for hydrogen fuel burning.

But Mazda has developed SPCCI ignition, which they say burns up all of the petrol/air mixture, raising efficiency greatly. Mazda say the engine can now compete with piston engines in economy and emissions. They say it gives the advantages of both petrol and diesel engines.

Many predict that Hydrogen will be used for large vehicles like trucks, buses, trains (already used trains) and ships. Expect to see rotaries filling the bill in some as the small size and weight will impact, but with EVs for cars.

Edited by RayTay on Monday 29th April 22:01

[RayTay]

23% greater fuel efficiency using hydrogen fuel rather than gasoline, with near zero emissions.
https://www.cder.dz/A2H2/Medias/Download/Proc%20PD...

Four-stroke reciprocating piston engines are poorly suited for conversion to hydrogen fuel. The hydrogen/air fuel mix can misfire on hot parts of the engine like the exhaust valve and spark plugs, as all four stroke operations occur in the same chamber.

Hydrogen/air fuel mixtures are quicker to ignite with a faster burning rate than gasoline. In a rotary engine each power pulse of the Otto cycle occurs in different chambers. The rotary has no exhaust valves that may remain hot that sometimes give backfiring in piston engines. The rotaries intake chamber is separated from the combustion chamber, keeping the air/fuel mixture away hot spots. All this lends the rotary engine highly suitable for the use of hydrogen without pre-ignition or backfire.

As hydrogen/air fuel mixtures are quicker to ignite than petrol mixtures with a high burning (flash) rate, resulting in all the fuel being burnt with no unburnt fuel being ejected into the exhaust stream as is the case using petrol fuel in rotary engines. Emissions are near zero, even with oil lubrication of apex seals. All these points lends the wankel engine ideal for hydrogen fuel burning.

But Mazda has developed SPCCI ignition, which they say burns up all of the petrol/air mixture, raising efficiency greatly. Mazda say the engine can now compete with piston engines in economy and emissions. They say it gives the advantages of both petrol and diesel engines.

Many predict that Hydrogen will be used for large vehicles like trucks, buses, trains (already used in trains) and ships. Expect to see rotaries filling the bill in some as the small size and weight will impact, but with EVs for cars.

Edited by RayTay on Wednesday 1st May 14:50

[rayyan171]

RayTay said:

23% greater fuel efficiency using hydrogen fuel rather than gasoline, with near zero emissions.
https://www.cder.dz/A2H2/Medias/Download/Proc%20PD...

Four-stroke reciprocating piston engines are poorly suited for conversion to hydrogen fuel. The hydrogen/air fuel mix can misfire on hot parts of the engine like the exhaust valve and spark plugs, as all four stroke operations occur in the same chamber.

Hydrogen/air fuel mixtures are quicker to ignite with a faster burning rate than gasoline. In a rotary engine each power pulse of the Otto cycle occurs in different chambers. The rotary has no exhaust valves that may remain hot that sometimes give backfiring in piston engines. The rotaries intake chamber is separated from the combustion chamber, keeping the air/fuel mixture away hot spots. All this lends the rotary engine highly suitable for the use of hydrogen without pre-ignition or backfire.

As hydrogen/air fuel mixtures are quicker to ignite than petrol mixtures with a high burning (flash) rate, resulting in all the fuel being burnt with no unburnt fuel being ejected into the exhaust stream as is the case using petrol fuel in rotary engines. Emissions are near zero, even with oil lubrication of apex seals. All these points lends the wankel engine ideal for hydrogen fuel burning.

But Mazda has developed SPCCI ignition, which they say burns up all of the petrol/air mixture, raising efficiency greatly. Mazda say the engine can now compete with piston engines in economy and emissions. They say it gives the advantages of both petrol and diesel engines.

Many predict that Hydrogen will be used for large vehicles like trucks, buses, trains (already used trains) and ships. Expect to see rotaries filling the bill in some as the small size and weight will impact, but with EVs for cars.

Edited by RayTay on Monday 29th April 22:01

Already is some hydrogen buses around London. Would be a good idea for a hydrogen engine from something light. Only real issue is storage of hydrogen, it is fine for buses/trucks as they are so big but for compact cars, they are a problem to store. Storage solutions are very heavy as well, apparently.

[RayTay]

Cars and lighter commercial vehicles look like they will most certainly be EVs.
For large vehicles there is the option of hydrogen fuels cells or direct burning in ICE engines. Large vehicles tend to have depots which can store the hydrogen. This is where the rotary shines as all the fuel mixture is burnt using hydrogen fuel. The biggest rotary ever made had a rotor diameter of 1 metre. Running on hydrogen these larger rotaries can fill the bill.

I cannot see hydrogen used in ICEs in trains, as the electric motor drive is far superior.

Edited by RayTay on Wednesday 1st May 15:05

[RayTay]

Mazda are to launch a rotary engine as a range extender. The best use for this engine.

https://www.gearpatrol.com/cars/a34315143/mazda-ro...

[otolith]

It's not a bad use for them, given their packaging advantages, but it's a very boring use for them.

[NMNeil]

I haven't read all the postings, so this may have already been covered, but there's a new take on the wankel which is supposed to be far better.
https://www.youtube.com/watch?v=jLtyNtf9_ew
https://www.liquidpiston.com/