Mazda did the thing engineers said was “basically impossible.” They put HCCI into a production car. HCCI = Homogeneous Charge Compression Ignition. Think: diesel efficiency + gasoline cleanliness — without a traditional spark timing the explosion. 🔧 How Skyactiv-X actually works Mazda’s engine uses a system called SPCCI (Spark Controlled Compression Ignition): • Air-fuel mix is very lean (much more air than fuel) • A spark plug does fire — but not to power the engine • The spark creates a small flame kernel • That flame rapidly raises pressure • The entire cylinder auto-ignites at once Instead of a flame front traveling across the chamber (normal gas engines), you get near-simultaneous combustion. ⚙️ Why this is so hard HCCI only works in a tiny window: • Too hot → knock • Too cold → misfire • Wrong load → no ignition • Wrong timing → engine damage Mazda solved this with: • Ultra-precise pressure sensors • Variable valve timing • High compression (~16:1, insane for gasoline) • A...