This document discusses advances in the combustion efficiency of direct injection diesel engines through the implementation of tangential swirling grooves in piston design. It examines various piston shapes and their effects on fuel consumption, emissions, and combustion characteristics, concluding that a flat bowl piston with tangential grooves significantly enhances engine performance. The proposed design aims to achieve better air-fuel mixing, increased efficiency, and reduced pollution, with potential future applications in more efficient automotive technologies.