Make no mistake, we agree with the industry shift toward producing low or zero emission vehicles. And we support manufacturers’ commitments to setting end dates for internal combustion production. But, we were very happy to see Mazda take a different approach.
Instead of unveiling a new electric or hybrid-electric powertrain, Mazda just let loose its new SkyActiv-X engine — an incredibly ambitious technological achievement made at the end of the internal combustion age. Here’s what you need to know:
Spark Plugs Make it Possible
The idea of using a lean fuel/air mixture for ignition is nothing new. It’s this concept known as Homogenous Charge Compression Ignition (HCCI), which ignites a lean fuel/air mixture by using an extremely high rate of compression without the use of a spark plug. It sounds good, should be good, but there was a problem: engines couldn’t control when the bang happened, which increased the risk of engine knocking, and an explosion in an engine is never a good thing. But don’t worry, Mazda arrived with spark plugs in hand.
Using an incredibly sophisticated Electronic Control Unit (ECU), Mazda’s SkyActiv-X engine utilizes spark plugs to give it the control it needs to reduce the risk of knocking. It’s a concept Mazda calls Spark Controlled Compression Ignition (SPCCI). It too uses a lean fuel/air mixture and compresses the mixture to combustion conditions. When the ECU sensors recognize optimal combustion conditions are met it reacts by igniting the spark plugs. When the spark plugs are ignited a fireball expands and controlled combustion occurs.
It’s Actually Efficient
By using a leaner fuel/air mixture, SkyActiv-X engines provide a 20 to 30% increase in efficiency, which is good for you and the planet, and its efficiency numbers are actually realistic. That’s because efficiency numbers are typically reported when the engine is off-boost and the throttle is barely in use (think low-speed suburban driving), but that’s not the case with SkyActiv-X. A small roots-like supercharger maintains a steady air supply, which allows for efficiency at higher speeds. In fact, the only time the engine switches to traditional spark ignition is when it’s working under a high load at a high RPM.
It Has Fuel Hurricanes
SkyActiv-X is full of little fuel hurricanes. Well, not really, but kind of. Fuel gets swirled into the SkyActiv-X like a hurricane to create a vortex with a stable center, sort of like the eye of a storm. The eye is not only more stable, it also forms a less lean area around the spark plug that can be ignited, unlike the rest of the cylinder’s lean mixture. And voila, an optimal condition for compression ignition is born.
If you thought, “Oh, yes! Ultra-high compression ratio, loud muscular sound!” We’re sorry to disappoint you, this engine is quiet as a mouse. It’s smooth too. But all this has the potential to change. SkyActiv-X is still in its infancy and may eventually roar with the angry sound you crave. We’ll just have to wait and see.
SkyActiv-X is expected to make its debut in 2019 in the next generation Mazda3 hatchback. If it proves successful, then it’ll be available in all of Mazda’s next new models.
For more info on SkyActiv-X stop by our Dublin Honda dealership and a member of our team will tell you everything you need to know about Mazda’s revolutionary new technology.
Until next time!