An Application Study of the Pneumatic Direct Injection Activated Radical Combustion Two-Stroke Engine to Scooter

As a promising solution for the reduction of CO₂ emission, the auto-ignition combustion is being intensively studied due to its potential for simultaneously decreasing CO₂ and NOx emissions. On the other hand, Downsizing can also be a general solution for the CO₂ emission. In case of four-stroke auto-ignition engines, however, there is a difficulty for the downsizing because of the limitation of specific power output.

An auto-ignition two-stroke engine was examined on a scooter frame, for the combined potential of the Downsizing and the auto-ignition. The results are that fuel economy was improved by approximately 70% in ECE40 mode, as compared with the 60% larger, conventional four-stroke engine. An additional small catalyst sufficiently purified the exhaust emissions sufficiently to meet the Euro 3 level.