Homogeneous charge compression ignition or HCCI engines are a unique prospect - use compression to ignite gasoline, like in a diesel vehicle. This allows for better fuel economy and lower emissions. A number of automakers have built prototypes and said they would be putting them into production down the road, but it has never happened. That may change in the near future.
The Nikkei Asian Review reports that Mazda will be launching an HCCI engine for the 2018 Mazda3 (Axela in Japan). This will be part of Mazda's second-generation of SkyActiv technologies to improve fuel economy. According to the report, the engine could give certain Mazda3 models a fuel economy figure of 30 kilometers per liter (about 71 mpg on the U.S. cycle). The report doesn't say if this is for city, highway, or combined.
Can Mazda do it or will it be like the others and not appear? We'll be watching to find out that answer.
Source: Nikkei Asian Review