Synthetic motor oils are not fake.. Synthetic oils also use different additives than conventional oils that are designed for extra wear protection and higher stability to temperature and shear. MYTH: Synthetic motor oil is bad for engine seals. Synthetic motor oil will not cause any damage to engine seals.
Over time, conventional oils can form sludge, which can reduce your engine's efficiency and, ultimately, reduce the life of your engine. Mobil 1 advanced full synthetic motor oils contain fewer impurities than conventional oils.
Sludge is basically the by products of combustion that get into solution- the oil. Use it long enough and the oil will break down and burn off only .
There are some engine oil myths that it's helpful to be aware of.. against rust corrosion, and to keep them free of sludge and general engine gunk.. we'll debunk them, along with a few other engine oil "facts" that don't happen to be true