While many carmakers continue to explore alternative fuels like hydrogen and refine battery-electric powertrains, Mazda is confident that there's still more efficiency that can be squeezed out of the venerable internal-combustion engine.
According to a report by Automotive News, the Japanese company aims to make its second generation of Skyactiv engines around 30 percent more efficient than the current generation - which already boast an admirably low thirst for fuel.
The diesels fare even better, with the Mazda6 consuming just 5.4 l/100km when equipped with the 2.2 litre Skyactiv-D turbo diesel.
If Mazda successfuly lops 30 percent off the consumption figures of its Skyactiv engine range, we could see a petrol-powered SUV with average fuel economy in the high 4 l/100km range, while the diesel Mazda6 could consume as little as 3.5-4.0 l/100km.
How will they do it? According to Mazda's powertrain boss Mitsuo Hitomi, refinements to the combustion process will net the results they're after.
"If we want to dramatically improve fuel economy from here, the only route is through lean burning," Hitomi said.
Lean burning means a reduction in the amount of fuel injected into each cylinder for a given amount of air, a technique that can produce more power with less fuel, but requires careful tuning to avoid engine longevity issues and emissions of harmful gasses.
An increase in compression ratio will also boost power and torque without impacting fuel consumption, and Mazda reportedly plans to take the petrol Skyactiv engines from an already high 14:1 compression ratio to an unbelievable 18:1.
And all this without a turbocharger in sight, either.
A timeline for the introduction of the Skyactiv 2 engine range has yet to be announced, however Hitomi hints that Mazda will need the new tech if it is to comply with tough European emissions legislation scheduled to come into effect in 2020.