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What Could Mazda be Cooking Up Behind Those Rotary Engine Rumours?

Daniel Wong September 23, 2015 16:39

If you haven’t been living under a rock, you might have heard about the rumours that are circulating around about Mazda working on a new rotary engine, and Mazda themselves have dropped some strong suggestions about what they have in store for the upcoming Tokyo Motor Show.

Rather coincidentally, during my recent trip to Hiroshima to visit Mazda’s production facilities, design studio, and sample their latest MX-5 last month, I came across a third-generation RX-7 parked in front of their design studio. It looked like any non-descript RX-7, except that it bore an R&D badge on its flanks, and didn’t have any registration plates.

With my curiosity piqued I took a quick glance inside and it looked like any other RX-7 interior save for research stickers being plastered around the base of its manual shifter. Being on the grounds of Mazda’s centre of operations, cameras were obviously barred from being used.

Seeing an RX-7 prowling around the factory lots of Mazda’s headquarters is a strange sight, considering its age and relevance to the Mazda. My suspicions were heightened when we went to Mazda’s Mine Proving Ground where we were told not to take any pictures except for those facing the circuit’s main straight. There wasn’t anything strange to be seen around the pit facilities.

But on the short tour of the circuit we sighted an open garage that held between five and six RX-7s wearing various pieces of body trim. Some with wings, and aerodynamic bits, some with headlight covers, some just left untouched.

On one hand it could look like cars that were kept that for the occasional one-make race series, or where local enthusiasts could come by and do some laps of the track.

But Mine (pronounced me-nay) has been designated as Mazda’s own vehicle testing facility and used to host Mazda’s CSR events on traffic safety and at times being used as the training ground for the Yamaguchi Prefectural Police. Not the sort of place you would randomly find a collection of ‘modern classics’ lying around sporting various body modifications.

Is Mazda Really Making a New Rotary Engine?  

It is highly possible that the number of RX-7s running around could be nothing more than a mere coincidence, after all it would be strange for Mazda to be using cars that it has discontinued 13 years ago as a development mule. A car that is famed for having an engine that requires frequent rebuilds and a fuel consumption that rivals that of a Ferrari.

The question of Mazda reviving the rotary engine is nothing new, and in fact it has been one of the industry’s most persistent rumours.

Companies like BMW constantly test different engine types to see if they can make it meet their internal standards. What’s more, Mazda has said on numerous occasions that they have continued development of the rotary engine in one way or the other, but won’t consider bringing it into production until they can get it to return the sort of fuel efficiency figures similar to that of a conventional piston engine, much less match those impressive figure achieved with their Skyactiv range of engines.

Mazda has been burned by rotaries before, their bet in adopting rotary engines in the 1970s brought the company to the brink of bankruptcy when the 1973 oil crisis hit the United States, Mazda’s main export market. In the meantime the company’s bet on Skyactiv fuel-efficienct technologies has worked wonders for the company’s image and fortunes, especially in today’s demand for low-emissions and fuel-efficient cars in markets such as Japan and Europe.

And yet, Mazda hasn’t totally forgotten their rotary engine heritage. Even though Mazda updated their museum installations to reflect Mazda’s current Kodo design language and Skyactiv technologies, in my recent visit I was surprised to find that they haven’t touched their entire rotary engine exhibit. It is still there today, even with educational installations extolling the merits of rotary technology, which seems all the more quaint in today’s context.

A screaming petrol guzzling engine might not make a modicum of sense anymore, especially in the context of Mazda’s long-term vision of “Sustainable Zoom-Zoom”. But what if it isn’t one in the spirit of the original lightweight and simple RX-7?

So How Could Mazda Realise a Rotary Engine?

Say that Mazda really is going to build a new RX series, one that adheres to the company’s focus on fuel-efficiency, how would Mazda get around to doing it?

One of the weak points of a rotary engine in today’s context is its low torque output, which gives it poor fuel consumption figures, especially when tested in standardised test cycles. The solution then would be to compensate for the lack in torque, and what better way to do it then attaching it to a hybrid system.

Think about it, a hybrid system can compensate for the engine’s lack of torque by taking over drive completely at low to medium speeds, giving a zero-emissions torque boost or even drive. And when more power is demanded, the rotary engine can be summoned in to deliver the power when needed.

In the meantime a rotary engine is remarkably light weight and compact compared to a conventional engine, allowing Mazda’s engineers to achieve their goal of engineering their cars to be lightweight, even with a heavy hybrid system on board. 

Introducing a hybrid system isn’t entirely excluded from Mazda’s plans for future products. After all Mazda does have a plan to boost the environmental performance of the cars by gradually adding electric drive technologies as they go along, with hybrids and electric vehicles are part of the plan as well.  

Alluding to our earlier post about the possible return of a rotary powertrain, the future does look possible for the rotary’s return, be it in a hybrid or plug-in hybrid form. Should it be a hybrid, the easiest hybrid powertrain to develop would be those with an electric motor mated to the transmission, which could be what was staring at my face at Mazda’s headquarters in Japan.

Imagine then a rotary-powered Mazda that takes after the hybrid sports car spirit such as the new Honda NSX, or take inspiration from the i8 plug-in hybrid. Interesting times are in store from Mazda indeed. 

About Daniel Wong

Born with a sizable cranium that is only humbled by Rubens Barrichello's, Daniel doesn't care much for numbers or figures but the immediate sensations and experiences one gets from a drive. To him a measure of a good car is one that does what it was set out to do well. A great car is one that draws a smile on your face with a quality that isn't quantifiable and keeps it there.


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