Mazda Upgrades Skyactiv-X ICE for 2021

Mazda will debut an upgraded version of its gasoline Skyactiv-X SPCCI Spark Controlled Compression Ignition petrol engine in two of its 2021 models.
Both the Mazda CX-30 and Mazda3 see the latest 2.0-liter e-Skyactiv X engine claiming 181bhp at 6,000rpm and maximum torque of 177ft-lbs at 4,000rpm. On top of this the automaker claims CO2 emissions have fallen by 5 to 11g/km, depending on model, transmission and trim level.
As an example the AWD GT Sport CX-30 automatic now emits 11g/km less CO2 with a 2mpg improvement in combined WLTP economy, while the entry-level front-wheel drive manual SE-L Lux CX-30 is 6g/km cleaner and is 2mpg more fuel efficient. The updates to Mazda’s 2.0-liter Spark Controlled Compression Ignition engine have been achieved through adjusting the compression ratio from 16.3:1 to 15.0:1, while other modifications include the reworking of combustion control, modified pistons and updating the Mazda M Hybrid mild-hybrid system’s software. The intake valve timing has been adapted through modifying the intake camshaft, this leads to a reduction in pumping losses and further increases the engine’s specific heat ratio, resulting in improvements to the e-Skyactiv X’s fuel consumption.
Additionally to the updates to the combustion engine, the Mazda M Hybrid mild-hybrid system has had a software update that enables faster reactions of the system’s belt-driven ISGs torque control. This improvement on control smooths drivability by increasing or reducing torque control when needed. For example, when the e-Skyactiv X’s air supply unit turns on, to provide sufficient air needed for a lean combustion fuel-air mixture, or off again, the units inertia creates torque fluctuations. The Mazda M Hybrid’s enhanced software enables torque reactions issued through the belt-driven ISG that are quick enough to flatten the torque curve. As a result, the engine feels even smoother during linear acceleration.
— Paul Myles is a seasoned automotive journalist based in London. Follow him on Twitter @Paulmyles_