What happens if we have a dirty lubricant?
If the lubricant has external contamination, it is recommended to investigate the source of the contamination and change the oil and filter. This is important, because external contamination can cause engine wear.
The black color of the lubricant does not indicate that it is in a bad condition; it is a sign that it is doing its job correctly. In the engine combustion process, soot and other impurities are generated that the lubricant must collect. The cleaning of the internal organs of the engine is one of the lubricant’s functions, so it must necessarily darken with the passage of time.