Mazda News: Mazda Creates "RE Development Group" to Work on Rotary Engines

[Anthony Fongaro]

Last year, Mazda brought back the rotary engine for the MX-30 EV crossover. Unlike before, the rotary engine now serves as a range extender in a serial-hybrid configuration. Mazda also showed off the beautiful Mazda Iconic SP Concept, which has a rotary engine working as a generator to charge the batteries. Now, Mazda is leaning into rotary engine technology again with a dedicated team. This "RE Development Group", previously disbanded in 2018, has 36 engineers to develop a next-generation rotary engine for EV use.

The last rotary-engine Mazda was in 2012 for the Japanese Domestic Market (JDM)-exclusive RX-8 Spirit R, and teased it again in the 2015 Mazda RX-Vision Concept. However, Mazda isn't looking to use the rotary in pure internal combustion vehicles. Instead, they are aiming for "attractive cars that excite customers with our challenger spirit."

There is a chance that something similar to the Iconic SP coupe will lead into production.  At the 2024 Tokyo Auto Salon last month, Mazda President and CEO Katsuhiro Moro is quoted as saying: "I am very happy and deeply moved by all the support and encouragement I have received for the compact sports car concept. I would like to take this opportunity to thank you all. With your encouragement, we are launching a rotary engine development group on February 1 to move closer to this dream."

A press release in February 2024 makes it clear that the rotary engine in the Iconic SP is only a generator. Unlike past RX models, future Mazda vehicles, such as the Iconic SP, use a two-rotor engine that powers up a battery. Rotary engines can run on gasoline, hydrogen, and renewable fuels. Although Mazda hasn't released the size of the battery pack, it can be charged from a domestic socket. Although producing the Iconic SP would take at least a few years, this would be Mazda's 13th vehicle to have a rotary engine. 

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[Drew Dowdell]

Rotaries are the perfect ICE for EV regenerators.  They are comfortable at the higher rpm that the generators need without causing noise and vibration to the passengers. No one likes a 3-cylinder or 4-cylinder screaming at them at 2,750 rpm, but a rotary at that speed is like nothing.

Plus, they're quite compact so they can fit in smaller vehicles like the Icon SP above or MX-30, or they can fit in something larger like the CX-90.

[G. David Felt]

COMPLEXITY, Right, not what the public wants, but some will say Hybrid is better than pure EV. 

I will acknowledge that for some a Hybrid will be better than a pure EV and this will probably be the last Hurrah for the Rotary till we get proper deep solid-state batteries into production.

[surreal1272]

Sorry but given the nature of Rotary engines (and the high costs of getting those engines serviced), all I can come up with is "why bother?". A two mode set up is already overly complex and now Mazda thinks it's a good idea to make it even more complex? Um, no. Just no.

[Drew Dowdell]

1 hour ago, David said:

COMPLEXITY, Right, not what the public wants, but some will say Hybrid is better than pure EV. 

I will acknowledge that for some a Hybrid will be better than a pure EV and this will probably be the last Hurrah for the Rotary till we get proper deep solid-state batteries into production.

It's a stop-gap.  It also lets Mazda produce low-medium range EVs with a range extender for those people who want mostly an EV but might have issues with the charging end of things and don't want the range anxiety.  Imagine a Leaf range but with a REV. There's a segment of the EV market that would go for it.

34 minutes ago, surreal1272 said:

Sorry but given the nature of Rotary engines (and the high costs of getting those engines serviced), all I can come up with is "why bother?". A two mode set up is already overly complex and now Mazda thinks it's a good idea to make it even more complex? Um, no. Just no.

What two-mode are you referring to?  I think the point here is that technology has progressed significantly since Mazda last went all in on a rotary.  I'm sure materials and design can improve on the old issues.  Additionally, since acting as a REV, the Rotary would be at a far less variable RPM which brings some advantages for durability.

[surreal1272]

19 minutes ago, Drew Dowdell said:

It's a stop-gap.

They have been trying to do something with the rotary engine for years now since the RX-8 and apparently they love beating that dead horse. A “stop gap” doesn’t normally involve a new ICE to go with the new EV powertrain. They have 4 banger options that they wouldn’t have to pour too much money into to create a true “stop gap” car. Thats my point here. Why the extra costs of a rotary engine development to go along with the extra costs of servicing said rotary engine, now the added bonus of an electric powertrain to deal with? Rotaries have never been known for long term durability  

 

And “two mode” may be the wrong term here but they are trying the RAM playbook only RAM was smart enough to leave in an already existing powertrain as opposed to slapping in a totally new one. Again, the costs are going to be stratospheric here. 

Edited February 5 by surreal1272

[Drew Dowdell]

18 minutes ago, surreal1272 said:

They have been trying to do something with the rotary engine for years now since the RX-8 and apparently they love beating that dead horse. A “stop gap” doesn’t normally involve a new ICE to go with the new EV powertrain. They have 4 banger options that they wouldn’t have to pour too much money into to create a true “stop gap” car. Thats my point here. Why the extra costs of a rotary engine development to go along with the extra costs of servicing said rotary engine, now the added bonus of an electric powertrain to deal with? Rotaries have never been known for long term durability 

The last Renesis was designed 20+ years ago for release in 2004.  The issue with the 4-cylinder options is size. The previous renesis was capable of over 230hp in a 1.3-liter engine that was physically smaller than any 1.3-liter out there.

20 minutes ago, surreal1272 said:

And “two mode” may be the wrong term here but they are trying the RAM playbook only RAM was smart enough to leave in an already existing powertrain as opposed to slapping in a totally new one. Again, the costs are going to be stratospheric here. 

Ah yea, you mean REV, range-extended vehicle.  That playbook goes back to the Bolt.

The way I am viewing this is that this will allow Mazda to range extend their smallest cars like the CX-30 and even the Miata.  I know there will be much wailing and gnashing of teeth when the Miata does go electric, but that is going to be an amazingly fun go-cart.

[G. David Felt]

2 hours ago, surreal1272 said:

And “two mode” may be the wrong term here but they are trying the RAM playbook only RAM was smart enough to leave in an already existing powertrain as opposed to slapping in a totally new one. Again, the costs are going to be stratospheric here. 

Do you mean dual rotor rotary motor which was in the RX-8 compared to this single rotor rotary generator?

[Drew Dowdell]

1 hour ago, David said:

Do you mean dual rotor rotary motor which was in the RX-8 compared to this single rotor rotary generator?

This is a dual rotor.

[G. David Felt]

17 hours ago, Drew Dowdell said:

This is a dual rotor.

Yes the MX30 concept is a dual but then Mazda talks about the future being a single rotor generator is how I took it, but then I could totally be off base due to the way they talk about it.

[Drew Dowdell]

27 minutes ago, David said:

Yes the MX30 concept is a dual but then Mazda talks about the future being a single rotor generator is how I took it, but then I could totally be off base due to the way they talk about it.

There are some smoothness concerns with a single rotor setup.  I could only see that being something they did for low cost hybrids. Not the luxury push they are going for.