alt Hacker NewsThe seal between the piston and the cylinder isn't perfect, so when the engine runs combustion products will mix with the oil, making the oil eventually unusable. That's why ICE engines meed oil changes so often.
The seal between the piston and the cylinder isn't perfect, so when the engine runs combustion products will mix with the oil, making the oil eventually unusable. That's why ICE engines meed oil changes so often.
And in fact it is necessary for it to be imperfect, and the oil is what lubricates the interface. So it is necessarily exposed to lots of heat and pressure.