Motoring: Mazda's Skyactiv-X the future of gasoline combustion engines

Header image for Interrobang article CREDIT: NAUMAN FAROOQ
Mazda's Skyactiv-X, is certainly something to look into and perhaps invest it when the time is right in the near future.

Mazda is a global company — its products are in just about every country on the planet. Mazda is mainstream — it does make lots of affordable vehicles that are bought by the masses.

However, Mazda is hardly conventional. This Hiroshima based, Japanese auto manufacturer might not be as big as Toyota or Ford, but it manages to develop new technologies that often surprises its competition.

For example, Mazda is the only company to have ever mass produced the rotary engine, and made it reliable — and it started out with that back in the mid-1960s.

In recent years, Mazda shook the engineering world, by coming out with a piston head design that was completely different from the norm — instead of being flat, the top portion of the piston has strategically shaped dips and peaks, to capture the energy from a combustion in a cylinder — and called it Skyactiv (the name comes from the motto given to the engineers, they were told, that the “sky is the limit” for developing these new engines).

But, Mazda wasn't done, it wanted to continue to innovate, so hence started looking at ways to improve comfort and handling of a vehicle. Mazda also studied how we sit in a car, and have been working on a seat that would provide a whole new level of comfort.

I was just in Irvine, California, at Mazda's North American Operations headquarters, and got to experience a glimpse into their new vehicle architecture, and that seat I mentioned; but the big story here, is their latest engine technology.

Mazda calls it, Skyactiv-X (compression-ignition gas engine), and this will lead to the future of the internal combustion engine. What makes this technology so extraordinary, is the fact that Mazda has managed to develop a gasoline engine that works like a diesel.

For those who don't know, a diesel engine doesn't require a spark to ignite the fuel - it relies on air compressed in a cylinder, which rises in temperature as it is squeezed, and when it reaches its optimal pressure, fuel is entered into the cylinder, which explodes, causing the piston to travel downwards. With cylinders lined up to perform this action in a timely manner, the resulting force spins a driveshaft, which then propels your vehicle.

The reason this formula worked only for diesel fuel and not regular gasoline, is because diesel is less dense and more combustible, so it can ignite without the need of a sparkplug.

Mazda sells diesel powered vehicles in most parts of the world (and will offer diesel powered vehicles in Canada and the U.S. in the near future), studied how diesel motors work, and started looking at ways to incorporate this technology to work with 87 octane gasoline.

This had never been done before, so Mazda was out on its own, developing the future of the internal combustion engine — a huge feat for a relatively small manufacturer that is not part of a conglomerate.

Mazda discovered, that in a normal gasoline combustion engine, a lot of heat gets trapped in the cylinder head after each revolution of the piston, which then mixes with fresh air on the next cycle. So, Mazda wondered, if the left over heat in the cylinder, when compressed, can be used to ignite the fuel?

The simple answer is, yes it can — but it was quite a bit more complex than that. The air-to-fuel mixture needed to be just right for each stroke, hence the Skyactiv-X motor has electric variable valve timing actuators. The fuel sprayed into the cylinder comes in finer, making combustion easier, and it needs to perform the same whether you're in the heat of Arizona or in the freeze in Alaska. Plus, it has to prove to be better than what currently exists!

There are no real fuel economy figures available for this new Skyactiv-X motor, because it is still in development. However, Mazda reckons that this new motor will be 20 to 30 per cent more efficient than their current gasoline engine of the same displacement. Power output wasn't mentioned at the presentation, but expect it to be the same or better than current engines.

But, why develop a gasoline engine that works like a diesel, when diesel exists?

First of all, it is cleaner for the environment. Diesel fumes pollute the air quite a bit more than gasoline, so a gasoline engine that gives the fuel economy of a diesel is better. Gasoline is also much more readily available —compared to diesel- at filling stations in most parts of the worlds, especially in Canada and the U.S.

Gasoline engines are also smoother, rev higher, and produce more horsepower compared to similar sized diesel engines, hence they are much more favoured by the buying public. Also, Mazda recognized that internal combustion engined vehicle will propel the masses globally for a very long time, so why not work towards making this form of powertrain cleaner and more efficient, rather than just bank on electric vehicles being the future — although, those will be offered by Mazda also, starting from 2020.

I got the chance to experience first hand, what this new Skyactiv-X tech is like. The vehicles at the event were early prototypes, hence we weren't shown how the motor comes to life when the car has been sitting off, but a display inside the vehicle did show in which mode the vehicle was running in at all times. If the screen read (1), then the motor had spark plug assist, like a regular gasoline engine, (2) meant that it was running in SPCCI (Spark Controlled Compression Ignition) mode — so just like a diesel motor, and a breakthrough for gasoline motors. When you saw (3) flash up on the screen, that meant you were running the motor “lean” - so the motor was ingesting more air than fuel, the most efficient setting.

The transition between these modes was fairly smooth, and you'd only really feel it if you were looking out for the switch points. The transition was also a bit more apparent on the automatic, mainly because it tries to get to the optimal setting as quickly as possible. A Mazda engineer, who rode along with me, mentioned that when this engine goes into mass production - which should be in 2019 — the transitions will be much smoother than what it is like in the prototypes.

From the driver's seat, the vehicle felt quite normal, which is what Mazda intended. The SKYACTIV-X motor felt smooth and powerful, while at the same time, improving fuel economy — after all, the less we pollute, the better it is for the planet.

If all this information is too much to ingest, just concentrate on the main points, and that is; Mazda is leading the way, again, on improving the internal combustion engine, which will not only benefit your pocket, but help preserve the planet, too.

But, that's not all.

Like I mentioned before, Mazda is also working on improving how a vehicle rides. Their new platform uses new suspension geometry to not only improve handling, but also to provide a much more comfortable ride — especially when you hit a bump.

Mazda has also been studying how we sit in a vehicle, and have hence been working on making a seat that would not only support our backside better, but also provide a more comfortable cushion.

Couple all that with a more soundproof cabin, and your car becomes a much more relaxing habitat.

For the buying public, Mazda's new platform and engine technology is about a year away, but it is coming, and based on the preview I experienced, it'll be worth the wait.