Mazda has revealed a 503bhp sports saloon with a rotary-electric powertrain that promises up to 500 miles of combined range.

The Vision X-Coupé – star of the brand's stage at the Tokyo motor show - is a sleek, rakish four-door that's clearly evolved from the striking Iconic SP sports car concept that Mazda revealed at the Tokyo show two years ago.

It is also, visually and conceptually, evolved from the 2015 RX-Vision concept, which set the tone for the Kodo design language the firm still deploys today and previewed plans for a new generation of powertrain based around a rotary petrol engine.

Mazda has not given any firm specifications of the new concept but says it uses a turbocharged two-rotor engine as part of a plug-in hybrid system - which is said to be capable of travelling 100 miles with the engine off.

The concept is also said to be capable of running on a carbon-neutral fuel derived from micro algae and is equipped with a "mobile carbon capture" device so "contributes to reducing atmospheric CO2 the more it is driven".

Mazda uses a rotary-electric powertrain in the MX-30 crossover already and has previously said it plans to put the 370bhp Iconic SP into production with the same technology - hinting at the technical viability of the Vision X-Coupé.

Unlike the mid-engined SP, though, this new four-door concept has its engine mounted at the front, under a long, probing bonnet that's a signature of the Kodo language. 

Overall, the new concept measures 5050mm long and 1480mm tall, making it the same sort of size as the similarly shaped Polestar 5 and Lotus Emeya.

The company has also been vocal about the potential for synthetic fuels to reduce the environmental impact of combustion engines and has invested in their development while EV uptake has faltered in many of its key markets.

Ultimately, with carbon capture and synthetic fuel capability in its future cars, Mazda has said it could even "evolve into a carbon-negative manufacturer" - meaning it captures more CO2 than it emits overall.