How to distinguish between black and green valve stem seals on Ford Focus?

[Ross]

Ford Focus valve stem seal color differentiation method: black seals are for exhaust valves, green seals are for intake valves. The function of automotive valves is specifically responsible for introducing air into the engine and expelling post-combustion exhaust gases. In terms of engine structure, they are divided into intake valves and exhaust valves. The intake valve's role is to draw air into the engine to mix with fuel for combustion; the exhaust valve's function is to expel combustion exhaust gases and dissipate heat. As Ford's best-selling compact sedan, the Focus has enhanced Ford's brand position in the global market with its excellent chassis and handling. The Focus has body dimensions of 4647mm in length, 1810mm in width, and 1468mm in height.