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I understand the concept of the cylinder being lined with a very thin layer of oil, which is partially burned off during the combustion process and the oil is replaced on the next piston stroke. The amount burned will differ between vehicles and even between different examples of the same engine, and depending on various factors. Also oil has some volatility or "burnoff" during a service interval which would (should) also show a lower dipstick reading as oil vapor is sucked through the PCV system and burned.
But... both of my road vehicles have the same dipstick reading, every time, throughout an oil service interval. Even at the end of a 7500-mile oil run, the dipstick level has not changed much if at all, I mean maybe it drops 1mm at the very most which is practically nothing. I am definitely not complaining! I just want to understand why the reading is consistent if the oil is being burned in the combustion chamber and also vaporizing. Maybe fuel dilution is making up for the lost oil volume? I know many of my friends' vehicles "never use any oil." I haven't done an oil analysis yet and I don't plan to since there are no issues. Just curious. Thanks!
I understand the concept of the cylinder being lined with a very thin layer of oil, which is partially burned off during the combustion process and the oil is replaced on the next piston stroke. The amount burned will differ between vehicles and even between different examples of the same engine, and depending on various factors. Also oil has some volatility or "burnoff" during a service interval which would (should) also show a lower dipstick reading as oil vapor is sucked through the PCV system and burned.
But... both of my road vehicles have the same dipstick reading, every time, throughout an oil service interval. Even at the end of a 7500-mile oil run, the dipstick level has not changed much if at all, I mean maybe it drops 1mm at the very most which is practically nothing. I am definitely not complaining! I just want to understand why the reading is consistent if the oil is being burned in the combustion chamber and also vaporizing. Maybe fuel dilution is making up for the lost oil volume? I know many of my friends' vehicles "never use any oil." I haven't done an oil analysis yet and I don't plan to since there are no issues. Just curious. Thanks!