A new development has surfaced regarding the will-they-won’t-they of Mazda’s speculated resurrection of the rotary engine. The US Patent & Trademark Office has just received two patent applications from Mazda Motor Corporation, both related to new innovations for rotary engines.
One patent features the rotary engine serving as a range-extending generator for an electric vehicle whilst the other is for the auto start/stop function for a direct-injected rotary engine. It is not explicitly stated if the two patents are for the same engine, although there is no reason to assume they are not.
This development ties in with earlier reports quoting a senior Mazda official that the company is planning to develop a new rotary engine for use in a range-extender EV by 2019.
Images attached with the patent application show the rough diagram of a front-wheel driven vehicle with a front-mounted motor but its range-extending generator, fuel tank, and battery placed at the rear.
We tested an early prototype operating such a configuration on the body of a previous-generation Mazda 2 in 2013. It was an effective demonstration on the rotary engine’s suitability for range-extender duty on account of its compact sizing.
Traditional concerns on the rotary engine’s notoriously poor economy and emissions also do not apply in this instance, as the motor will be locked to operate at a fixed engine speed (around 4,000 to 5,000rpm) with its fuel usage optimized to the best possible degree.
Mazda’s idea of using a rotary engine to serve as an electric vehicle’s range extender is unusual and intriguing in equal measure, but there’s no guarantee that even with a patent application that the final product will make it to production.
Don't even hold your breath for a new generation rotary sports car just yet.