Most people can differentiate between a diesel and a gas engine. The most common difference being that diesel engines don't have spark plugs, rather they use high compression to combust the air fuel mixture. Well, Mazda was the first to say why not use compression ignition in gasoline cars? This technology is called Homogeneous charge compression ignition (HCCI). Theoretically, it works. It requires a lot of volatile and complex additions to the traditional internal combustion engine. Now this does not mean that these new engines will not have spark plugs, rather that these engines use their spark plugs only when power is demanded.
Mazda has implemented technology that injects a small secondary amount of fuel into the swirling mixture that is the high compression of fuel/air, this change in temperature activates the combustion, sans spark plug.
Downsides. The new engine developed by Mazda, is unfortunately prone to a few downsides. Due to the high engine speed limitations, the RPMs of the engine are pretty low. It is also difficult to synchronize the engine without spark plugs. This could result in misfires of rod knock later down the road.
The 2.0L I4 produces 190 hp and 207 lb/ft of torque. An upgrade by up to 35% efficiency is reported by the EPA estimates from the previous Mazda skyactive engine. Even in lean fuel mixture mode, the Mazda is more powerful and efficient with no compromise
I suppose this is Mazda's answer to Nissans VC-Turbo, another revolutionary redesign of the internal combustion engine. Both are clever, but are they clever enough to compete with the electric car empire slowly taking over the future of automobiles?