Mazda’s New SkyActiv-X Brings Clever Compression Ignition

Mazda are no strangers to the engine development game. The Wankel rotary in the RX-7 was nothing short of miraculous with its 1.3 litre capacity and its 280 horses. It went like the proverbial. What wasn’t so amazing was its fuel economy and it predisposition to spectacular failure due to worn rotor tips. Still, it has won a place in every petrolheads heart as it’s a lovely responsive engine to drive with a power to weight ration that’s hard to beat.

Well the technical team behind that has turned its attention to a clever new development of the humble petrol driven internal combustion engine.

SkyActiv-X – Less Fuel, More Air

The problem with petrol engines is that they need a certain amount of fuel to explode reliably. The ratio of fuel to air is critical for a reliable explosion every single time the piston is at the top of the cylinder but wouldn’t it be great if you could burn more air and less fuel. You would have a cooler engine with less need for power to be lost with all that messy water cooling. The best solution to this might be diesel engines compression ignition where the fuel and air gets squeezed in the cylinder until it explodes pushing down the piston and moving you to B.

Petrol Engine with Diesel Tech – SkyActiv-X

So Mazda has done exactly that with the new SkyActiv-X engine, a development of the Skyactiv-G. In effect they have made a hybrid system that uses both a spark plug and compression ignition. The high air mixture is squeezed until it explodes but the spark plug also helps because compression ignition doesn’t work if its too cold or if the engine is running too slowly. The presence of the spark plug also allows the engine to rev up to higher petrol RPM’s rather than getting stuck at 5000. Mazda calls the technology the imaginative moniker SPCCI or Spark Controlled Compression Ignition.

SkyActiv-X So Why Is That Good?

The excellent news is at least a 20% increase in fuel efficiency than the previous generation and more if you do city driving. We also get a 10-20% increase in torque so more grunt away from the lights. So you can go further and have more fun in your 2019 Mazda. Now we just need a new rotary-engined sports car.

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