Mazda's renowned rotary Wankel engine has been a staple in some of the carmaker’s sports cars for the last 44 years, with its first appearance in 1965 and its continuing application in the current RX-8 model. Throughout that period the engine has gone through a number of significant changes, and it seems Mazda isn't finished fine tuning its rotary engine just yet, as a recent patent application shows the carmaker is planning to apply direct-injection technology to it.

Filed in October last year with the U.S. Patent and Trademarks Office, the design depicts a new direct-injection version of the trademark Wankel Rotary engine used by Mazda. Adding direct-injection into the mix may help the Wankel engine improve its efficiency in terms of fuel use - currently, the engine used in the Mazda RX-8 manages to muster an impressive 228hp from its tiny 1.3L displacement but regularly achieves fuel consumption figures of 18mpg (13L/100km).

Staff at Mazda's engine development unit have previously stated that improving power and reducing fuel consumption was one of their key focuses in building the new rotary engine, an intention confirmed by the fact that the patent application for the new twin-spark direct injection rotary engine features a diagram highlighting how fuel consumption will be decreased.

A new ‘RENESIS’ rotary engine has previously been confirmed by Mazda, known internally as the 16X engine. It’s expected to debut in a new high-performance sports car that many believe will be a successor to the FD RX-7. In addition to the new engine, the car will also feature a dual clutch transmission when it arrives in around three years.

While it’s not certain that the engine depicted in the patent applications will be going into production, it gives us a glimpse into how Mazda may be thinking about improving its rotary engine for the future, and with fuel consumption a major focus for the development team we should see the next Mazda rotary model significantly improved in this area.