We have to hand it to Mazda. Lately, the small Japanese automaker has punched well above its weight with the announcement it would bring a gasoline Homogenous Charge Compression Ignition (HCCI) to market in 2019, dubbed Skyactiv-X.

But, what's this? Another piece of news surrounding a future Mazda engine and it doesn't seem to be related to the HCCI engine. It's a gasoline-powered internal-combustion engine with two turbochargers and an electric supercharger. The patent images clearly show two exhaust-driven turbos plus a single supercharger powered by electricity. The patent goes on to describe the forced induction's role as well. The electric supercharger would supply low-end power while the traditional turbos spool up. What's unclear is how Mazda plans to power the electric supercharger.

Something else that's intriguing about this patent: it's shown fitted in a rear-wheel-drive application. The only rear-wheel-drive vehicle Mazda currently builds is the MX-5 Miata, which leaves us wondering what the automaker is cooking up. Digging even deeper shows Mazda has also patented a near-identical engine that's described to run on diesel fuel as well.

Mazda previously said its Skyactiv-X engine would use a supercharger, but turbos weren't mentioned in the initial announcement, which only intrigues us further as to what's going on here. Automakers often patent solutions without the intention of actually bringing whatever the system or product is to market, but we hope to see more of whatever this particular engine is in the future.