8 Common Motor Oil Myths Debunked

April 16, 2019 | News

There are many myths in the world about motor oil and its properties. Here are 8 of the top myths and why they are wrong.

Myth #1: Once you switch to synthetic oil, you can never switch back.
FALSE. This is one of the most persistent myths about synthetic oil-and completely untrue. You can switch back and forth at any time. In fact, synthetic blend oils are simply a mixture of synthetic and conventional oil. However, synthetic oil provides the best performance for your vehicle's engine, especially at high engine temperatures.

Myth #2: If you use synthetic oil, you can change your oil less frequently.
FALSE. Oil drain interval recommendations are set by the original engine manufacturer (OEM). The point of using high-quality synthetic oil is to take better care of the engine over the entire oil drain interval and reduce deposit formation-not to extend the drain interval.

Myth #3: You shouldn't use synthetic oil in an older vehicle.
FALSE. The myth is rooted in the idea that synthetic oil is "slipperier" (lower in viscosity), or not as compatible with seals, and will therefore leak or leak more in places conventional oil might not. Again, completely untrue. Synthetic oils will enhance the engine protection in older vehicles, just as they do for new engines. Always follow the engine oil specification recommended in the owner's manual.

Myth #4: You need a thicker motor oil for extra wear protection.
FALSE. This is one of the most common car care myths out there. First off, it is the antiwear additives (ZDDP or "zinc") in the motor oil formulation that provide wear protection, not the motor oil viscosity grade. Using a motor oil that is too thick may decrease engine efficiency. Many modern and newer vehicles recommend lower viscosity grades for better fuel economy and tighter tolerances. Always follow the viscosity grade recommended in the vehicle owner's manual.

Myth #5: Synthetic oil is slipperier and causes your engine to leak.
FALSE. Some drivers believe that synthetic motor oil causes your engine to leak because it is slipperier - that is FALSE! Slipperiness has to do with the motor oil viscosity grade, regardless of type. Synthetic oil will NOT cause your engine to leak. Synthetic motor oil actually provides better protection for your engine at extreme temperatures. Always follow the vehicle manufacturer's recommendation for engine oil.

Myth #6: If your oil is black then you definitely have to change it.
FALSE. The main reason that motor oil darkens is due to oxidation, which happens much more rapidly when the motor oil is exposed to high engine temperatures. Motor oil also darkens as it absorbs by-products from combustion. This means your motor oil is doing its job! Always follow the vehicle manufacturer's recommended oil change interval.

Myth #7: High mileage engines just need thicker oil to reduce leaks.
FALSE. High mileage motor oils are specifically formulated for older engines to help reduce oil consumption and contain seal swell additives to help reduce leaks. Always follow the vehicle owner's manual for the correct viscosity grade.

Myth #8: You need to use thicker motor oil when it's hot outside.
FALSE. Always follow the OEM recommendation regardless of the outside temperature. Remember, engines operate MUCH HOTTER that any summer day! Using motor oil that is too thick may decrease engine efficiency and fuel economy.

8 Common Motor Oil Myths Debunked

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