Embed piston ring is a metal used inside the piston ring grooves, piston ring can be divided into two types: compression ring and oil ring. Piston ring is a kind of outward expansion deformation of the bullet-shaped metal ring, which is assembled into the annular groove of the cross-sectional configuration with its mate. Reciprocating and rotational movement of the piston ring and rely on gas or liquid pressure difference between the cylinder and the side ring and ring and ring groove of the outer surface to form a seal. Piston ring is a core component of fuel within the engine, and it cylinders, pistons, cylinder walls and other seal with the completion of fuel gas. Common car diesel engine two kinds of gasoline engine, its fuel due to the different performance, piston rings are not the same.