- LSD
- Abbreviation for Low sulfur diesel fuel
- L-section ring
- A special piston ring characterized by its L-shaped cross-section. It is used mostly in high-performance two-stroke engines. The L-section ring allows combustion gas to penetrate behind its vertical section and thus uses the gas pressure to increase the pressure of the ring against the cylinder wall
- LSPV
- Abbreviation for Load Sensing Proportioning Valve