Mazda is committed to petrol-powered cars in the medium term, having invested heavily in a revolutionary technology likely to arrive in its next generation of small cars.

The technology, known as homogenous charge compression ignition, or HCCI, combines petrol and diesel engine traits in an efficient package. Any car enthusiast can tell you that the main point of difference between diesel and petrol engines is that a petrol motor uses spark plugs to ignite petroleum, whereas diesel engines apply brute force, compressing oil-rich diesel fuel to the point of combustion.

Engines that operate using HCCI are capable of detonating petrol under extremely high compression without the use of spark plugs. Several manufacturers including General Motors, Honda, Hyundai and Mercedes-Benz have experimented with the technology as a means of increasing fuel efficiency.

But Mazda is expected to be the first to sell it to the public, and the brand is expected to offer an important insight into its HCCI program in August. 

Senior Mazda engineer Kenichiro Saruwatari told Drive the next-gen engine’s introduction is “top secret”, saying only that it will be available “sometime in the near future”.

Industry speculation suggests it will arrive in the next-generation Mazda2 or Mazda3 hatchbacks.

Saruwatari says Mazda has revisited the “traditional idea” of HCCI, which has been around since the 19th century.

The engineer says his brand “always thinks about how to make the combustion more efficient”, and that Mazda will build on its current Skyactiv technology with a motor capable of running both as a regular four-stroke petrol engine with spark plugs, or through HCCI in some circumstances.

While other brands have done so in concept form, he says it is not possible to make a production engine run purely on an HCCI cycle.

“It is very difficult to use the use the HCCI at all times,” Saruwatari says. 

“In certain area it needs to use the combustion area with the sparkplug – it is mixed.

“At high RPM, high load there is no sparkplug.”

Mazda isn’t alone in pushing boundaries with compression ratios in production engines.

Infiniti is set to offer a variable-compression engine in future models that allows it to minimise fuel use and maximise power outputs according to driver demand.

It is too early to say when the technologies will arrive in Australia. Local fuel quality may be a sticking point, as Australia’s notoriously sulphur-rich fuel is well below world-class standards, which carmakers say could limit the introduction of high-tech engines in the future.

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