Last month, Mazda announced that it would be introducing the world’s first production petrol engine with compression ignition technology, dubbed SkyActiv-X, in 2019. At the company’s recent global tech forum last week, Hiroshima revealed more details about the new mill and explained in plainer terms how it works.

Compression ignition allows for a much leaner air-fuel ratio (more than 30:1 as opposed to the stoichiometric ratio of 14.7:1 on a typical petrol engine, Mazda claims), which vastly improves efficiency. The only problem is that there is no way to control the timing of the ignition, so it can really only be used under very light loads.

To solve this, Mazda reduced the compression ratio of the engine just enough so that the fuel doesn’t spontaneously ignite. To kickstart the combustion process, a spark plug ignites a small amount of rich mixture around it; the resulting flame kernel raises the pressure within the combustion chamber, burning the rest of the mixture that is leaner. Mazda calls this Spark Controlled Compression Ignition (SPCCI).

With this technology, Mazda claims the engine can run on compression ignition more than 90% of the time, increasing engine efficiency by between 20 and 30% over the current SkyActiv-G engine and between 35 and 40% over a Mazda petrol engine of a similar capacity from 2008.

The technology is so effective, the company says, that the 2.0 litre SkyActiv-X engine achieves fuel efficiency that equals or even exceeds that of the 1.5 litre SkyActiv-D diesel engine. The mill is also fitted with a supercharger and is claimed to offer improved response and between 10 to 30% more torque compared to the 2.0 litre SkyActiv-G engine, which Mazda says is equivalent to the larger 2.5 litre motor.

As a result, the engine is said to be highly efficient across a wide range of engine speeds and loads, enabling a much larger spread in terms of gear ratio selection – this, Mazda says, provides superior fuel economy and driving performance.

Also announced is the company’s next-generation platform, which is expected to be used on the next Mazda 3. Developed with greater focus on a human-centred concept, it is claimed to offer a more comfortable and less tiring drive, optimising the body, suspension, seats and even the tyres to enable drivers to respond quickly to environmental changes, using the human body’s “natural ability to balance itself.”

To do this, the seats have been redesigned to keep the pelvis upright and maintain the spine’s natural S-curve, and even the mounts and other components have been made more rigid – as has the seat structure itself – to transfer inputs from the sprung mass (i.e. the vehicle body) to the driver’s body in a smoother, quicker and more direct manner.

With that settled, engineers moved on to the rest of the car to achieve the perfect response and a more direct jinba ittai driving feel. The body has been made more rigid across all four wheels by the addition of frames connected not just vertically and laterally, but also fore and aft – this creates multi-directional ring structures that enable the transfer of inputs without delay.

The chassis has also been redesigned to optimise the functional distribution of the suspension, tyres, arms and dampers, enabling each part to work interactively to smoothly control the transfer of energy to the sprung mass. Noise, vibration and harshness (NVH) has been improved through the use of damping nodes, damping bonds and other efficient damping structures at high-strain energy areas.

Although the new Mazda 3 won’t arrive until 2019, a concept previewing the next-generation C-segment model is expected to be unveiled at the 2017 Tokyo Motor Show in October.