In case you thought the gas-powered internal combustion engine was running out of tricks, Mazda has proven that this old dog isn't ready to sit and stay just yet.

Mazda on Tuesday unveiled a compression-ignition gas engine as part of its "Sustainable Zoom-Zoom 2030" plan, which lays out Mazda's long-term plans for technology development. This new family of gas engines will reportedly power the next-generation Mazda3, which could make an appearance in concept form as early as the Tokyo Motor Show in October. For now, Mazda has not said what car this new engine would occupy, only that it would hit the market in 2019.

Enlarge Image Nick Miotke/Roadshow

The engine is technically called a homogenous charge compression ignition (HCCI) engine, which Mazda will call Skyactiv-X for marketing's sake. The engine will function like a traditional gas engine at low revs, using spark plugs to ignite the air-fuel mixture in the combustion chamber. At higher revs, though, the plugs will deactivate and the gas will ignite under piston compression alone.

In case you're keeping track at home, that's how diesel engines function, using compression to ignite the air-fuel mixture.

HCCI is believed to produce a more efficient combustion, which keeps fuel economy high and emissions low. It should also reduce the chance for the air-fuel mixture to combust prematurely, which is known as knocking. Mazda claims that, in conjunction with a supercharger, the Skyactiv-X engine could deliver "unprecedented" engine response and increase torque by 10 to 30 percent over the current family of gas engines. This technology can also improve engine efficiency by 20 to 30 percent compared to the current Skyactiv-G gas engine.

The rest of Mazda's sustainability report focuses on ways to make the company itself cleaner. Mazda wants to reduce total "well to wheel" carbon dioxide emissions -- meaning the net carbon dioxide output from raw materials to finished vehicle -- to 50 percent of 2010 levels by 2030. By 2050, it wants to reduce emissions up to 90 percent of 2010 levels.

Starting in 2019, the company wants to begin introducing electrified vehicles in its lineup, including both actual electric vehicles and "other electric drive technologies," likely referring to hybridization. It also plans to start testing its semiautonomous driving technologies in 2020, hoping to make the stuff standard by 2025.

In the interim, Mazda wants to continue focusing on the basics. It wants to keep advancing its suite of active and passive safety systems, starting by making some of them standard as early as 2018 (Mazda has already done this with the 2018 Mazda3). Mazda also believes more progress can be made on what it calls the fundamentals, including "correct driving position, pedal layout and good visibility," which the automaker wants to standardize across its lineup.

Mazda isn't the only automaker getting weird with the gas engine. Infiniti rolled out the VC-Turbo engine at the 2016 Paris Motor Show. A complicated linkage system in the block allows the engine to change the piston's stroke at will, which will vary its compression ratio between 8.0:1 and 14.0:1. Infiniti believes its four-cylinder VC-Turbo will be 27 percent more fuel-efficient than a similarly capable gas V6.

Update, Aug. 8: Added more detail following the official release of Mazda's sustainability report.