The objectives of this project were to determine the acceptability of various types of stratified charge engines as potential power plants for light duty vehicles and motorcycles in America. The light duty vehicle considered was a four/five seat compact sedan with good acceleration capabilities and exhaust emissions below a primary target of 0.41 g/mile HC, 3.4 g/mile CO, 1.5 g/mile NOx. A secondary target of 0.41 g/mile HC, 3.4 g/mile CO and 0.4 g/mile NOx was also considered.A literature survey was undertaken, comparing stratified charge engines with examples of good conventional gasoline and diesel engines. While some stratified charge engines had exhaust emission or fuel economy advantages, there were always sacrifices in other areas.Eleven engines were configured, four of which were specifically directed towards the secondary emission targets. A method of rating the engines was derived, and the design concepts were compared with two gasoline engines by a jury panel. The overall result was that the Ford PROCO and Honda CVCC combustion processes were serious contenders to the gasoline engine at the primary emission target, and that both of these systems, together with the VW combustion process, might be suitable at the secondary targets.