Mazda SKYACTIV-X engine rivals EV CO2 emissions claims the car company
Mazda has made some big claims about its new SKYACTIV-X engine, claiming almost emissions parity with electric cars.
The SKYACTIV-X engine combusts through combustion ignition and combines the best of both petrol and diesel cars.
Mazda has claimed that until the growing quantity of power from renewables replaces the dirtiest forms of electricity generation such as brown coal, electric powertrains do not currently satisfy to society’s wish for a drastic reduction in greenhouse gas emissions.
This is why the manufacturer is focusing on maximising the efficiency of the internal combustion engine.
However, this does not mean that the company is turning away from electric cars.
Mazda will introduce an EV and mil hybrid model in 2019 and the brand’s first hybrid in 2025.
The company also wanted to reduce average ‘Well to Wheel’ CO2 emissions to 50 per cent of 2010 levels by 2030 and by 90 per cent by 2050.
The car manufacturer has also claimed that placing the absolute emissions of an electric vehicle as zero is disingenuous.
This is because current techniques to measure CO2 emissions are only measured while driving.
Mazda argues that ‘well-to-wheel’ emissions should be measured, which considers fuel extraction, manufacturing and shipping.
The firm argue that researching this will allow the company to accurately assess the appropriate powertrain development paths for EVs.
To illustrate the efficiency of their new engine the firm compared the well-to-wheel emissions of the SKYACTIV-X vs man EV.
It said: “A mid-sized electric car consumes around 20 kilowatt-hours of electricity per 100km. Production of this power with coal translates into CO2 emissions of 200g/km; with petroleum, 156g/km; and with LNG (liquefied petroleum gas) 100g/km.
“When converted to a ‘Well-to-Wheel’ figure, then, the average CO2 emissions of an EV are some 128g/km, depending on the power generation source, whilst that of a Mazda SKYACTIV-G petrol engine of comparable power is 142g/km.
“This means that with as little as a 10 per cent improvement in efficiency, SKYACTIV-G engine emissions will be on a par with those of electric vehicles.”
“In fact, a SKYACTIV-G engine produces less CO2, ’Well-to-Wheel’, than EVs whose electricity is generated by coal or petroleum.
“And whilst EVs using LNG-produced electricity have 30 per cent lower emissions, Mazda believes it can improve the internal combustion engine sufficiently to match that level.”
The SKYACTIV-X is the world’s first commercial petrol engine to use compression ignition, which spontaneously ignites the fuel-air mixture when compressed by the piston.
The engine combines the elements of a petrol engine and a diesel powertrain
Dubbed Spark Controlled Compression Ignition (SPCCI)it combines the spark ignition of a petrol engine with compression ignition of a diesel.
Two of the key factors to the successful operation of SPCCI are; firstly, the engine’s ability to switch from the ideal, stoichiometric, 14.7:1 air-to-fuel mixture of a conventional petrol engine to the lean-burn mixture -over 29.4:1; and secondly, the continuous use of spark plugs.
When the engine is cold or running at high revs, the spark plugs ignite the mixture in a conventional manner.
The powertrain is said to produce an increase of torque of 10-30 per cent and improve engine efficiency by up to 20-30 per cent over the SKYACTIV-G and even equal or exceed the SKYACTIV-D diesel engine in fuel efficiency.