Synthetic Oil Myths
Knowing that a person can never stop learning, I am always trying to better my knowledge. I was reading "Engine Builder," the magazine, and came across a great article by Pennzoil themselves.
Myth 1: Synthetic oils are too thin to stay in the engine. This is not true. In order for a lubricant to be classified in any SAE grade (10W-30, 10W-40, etc.) it has to meet the viscosity guidelines, or thickness, specified by the vehicle manufacturer.
Pennzoil, "Tech Notes," Engine Builder, September 2006, 16.
Myth 3: You can’t switch between conventional oil and synthetic oil. Switching between synthetic and conventional oil will not cause any harm to engines. Synthetic oils and conventional oils are formulated to help protect your emission system, including oxygen sensors and catalytic converters.
Pennzoil, "Tech Notes," Engine Builder, September 2006, 16.
Myth 4: Synthetic oil will makes seals leak. If an older engine’s seals do not leak with conventional oil, they will not leak after switching to synthetic oil. Synthetic oils do no damage engine seals in an engine of any age.
Pennzoil, "Tech Notes," Engine Builder, September 2006, 16.
Myth 5: Synthetic oil cannot be used to “break in” a rebuilt engine. In a rebuilt engine, a certain amount of controlled wear can be expected to occur to allow piston rings to “seat” and the engine to “break in.” Synthetic oil may be used for the “break-in” period and throughout the life of the engine.
Synthetic base oils combined with a strong additive package allow synthetic oils to perform better than conventional motor oils under virtually all conditions.
Pennzoil, "Tech Notes," Engine Builder, September 2006, 16.
I personally have been a firm believer that many stories of synthetic oils are myths. In ALL our race motors, we have never broken in a motor on conventional oil and we have all switched between different oils in between time.
I have built motors for my team members that literally go directly on the dyno right after assembly and installation for a full dyno tune. A lot of wear occurs on initial start up so that is when the motor needs the most protection; this is why I like synthetics for break-in.