The SkyActiv-X, a step up from the SkyActiv-G (petrol) and SkyActiv-D (diesel), remains fuelled by petrol but uses the compression-ignition just like a diesel, giving a 20-30 per cent improvement in efficiency.
The Japanese manufacturer claims that this efficiency advantage will make the SkyActive-X environmentally superior to many electric vehicles (EVs) in the “well-to-wheel” (fuel extraction to driving) department.
In addition, Mazda claims that comparitively, a SkyActiv-X car petrol model is potentially cleaner than a 21.2kWh EV, once non-renewable electricity generation is taken into account: 142g/km for SkyActiv-X, compared to 200g/km for an EV powered by coal-fired electricity and 156g/km for petroleum-produced power.
Mazda says that according to its calculations, the cleanest thermal power generation method is Liquid Natural Gas which beats SkyActiv petrol at 100g/km.
The company believes that this “crossover” technology can bring together the fuel economy, torque and response of a diesel engine with the power and cleaner exhaust of a petrol one.
The SkyActiv-X is still a prototype, but Mazda expects it to be production ready by 2019.