Tokyo show: Turbo likely for Mazda rotary

MAZDA’S reborn rotary engine could eventually be offered with turbocharging or hybrid power options, according to the company’s research and development chief.

The Japanese car-maker lifted the lid on its RX-Vision Concept at the Tokyo motor show, revealing a sinuous sportscar study that uses the latest version of an engine type that is synonymous with Mazda.

Speaking with Australian journalists at the motor show, Mazda Motor Corporation managing executive officer in charge of research and development, Kiyoshi Fujiwara, said that the rotary powertrain his team have been working on is based on the same 16X unit under the bonnet of the 2007 Taiki concept.

Discussing the potential for electrification or turbocharging technology to be paired with the rotary, Fujiwara-san said his aim is to first ensure the rotary unit is capable enough on its own.

“If we can produce this kind of engine and this kind of product (RX-Vision) with a rotary engine, I would like to introduce a complete rotary engine itself – no electrification,” he said. “Because if we add some help of electrification, people will say this electrification helped the rotary engine.

“Therefore, personally, I want to introduce new rotary engine without electrification.”

Fujiwara-san said if CO2 emissions requirements become even stricter in the future, “then we continue to add electrification”, before suggesting that turbos will also feature down the track.

“Turbocharge (sic) is one of the big contributors to future rotary engine,” he affirmed.

He added that the company would use rotary powertrain technology to produce mass-market range extenders for use in other applications, such as electric vehicles. This was announced at the 2013 Tokyo motor show with the debut of the Mazda2/Demio EV concept.

Fujiwara-san said “some other brands” were interested in using Mazda’s range extender tech, but did not elaborate.

Fujiwara-san confirmed that the engine capacity will be 1.6 litres, the same as the 16X unit.

While the RX-Vision is yet to be officially confirmed for production, it is widely believed a rotary-powered sportscar will go on sale later this decade, possibly as a 2020 model year vehicle.

In terms of timing for production of the rotary powertrain, Fujiwara-san said prototype testing would commence “soon”.

“We have technical solutions on rotary engines, but we need time to validate the quality issues by an actual prototype vehicle with a prototype engine driving in an actual market like Australia or Asia,” he said.

Fujiwara-san also ruled out use of rotary power in anything other than a sportscar model, and added that the spend on the engine’s development had not come at the cost of any other projects.

“Ninety-nine per cent of R&D resources is used for SkyActiv gasoline, SkyActiv diesel and other SkyActiv transmissions,” he noted. “Only three or one per cent is just for use of rotary engine for this model.”

Fujiwara-san also acknowledged that the sharing of platforms between the discontinued RX-8 and previous-generation NC MX-5 was “not an ideal situation.” He said that the new-gen MX-5 platform will be only used for the drop-top.

The dimensions of the RX-Vision are 4389mm long, 1925mm wide and 1160mm high with a 2700mm wheelbase the exact length of the wheelbase of the CX-5 crossover. Despite this, Fujiwara-san said the RX-Vision would not be based on the SUV’s underpinnings.

“This kind of sportscar cannot use a current passenger car (platform), because it is quite low height and more lighter weight is required,” he said.

“Therefore we have to consider more clever solutions.” Fujiwara-san said that any future production sportscar would showcase the use of new high-tech lightweight materials in a similar way that the RX-8 led the way for the brand with aluminium and friction welding.

“Firstly, we use this kind of new technology on a sportscar, then this kind of technology can be delivered to new passenger cars,” he said. “Therefore this RX-Vision may have a new technology for body and chassis, including the material. Then technology will be delivered to next-generation passenger vehicles.”