4 Oil Change Myths—Busted!

  • Dec 21,2016
Firestone technician emptying oil from a car to replace with fresh oil Firestone technician emptying oil from a car to replace with fresh oil

From stories of Hercules to New York’s sewer alligators, myths can be fun to tell and hear. Whether such tall tales hold a grain of truth or not, there's always a part of you that wonders. Does lightning ever strike the same place twice? Could dropping a penny off the Empire State building actually hurt someone? Can I switch back and forth between synthetic and conventional oil? While some myths are relatively harmless, others could do some pretty serious damage if believed. (Get this: lightning really can strike the same place twice, and often does!) So forget urban legend. Follow along as we debunk some of the most common oil change myths in an effort to keep your engine running stronger, cleaner, and longer!

Myth #1: I need a thicker motor oil for extra wear protection.

This is one of the most common car care myths out there. First off, it is anti-wear additives (ZDDP or “zinc”) in the motor oil formulation that provides proper 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.

Is it time to get your oil changed? Schedule an appointment.

Myth #2: Synthetic oil is slipperier and causes your engine to leak.

When synthetic motor oil first came around in the 1970s, a few synthetic oil myths began to evolve. Unfortunately, these myths have stuck around, regardless of their accuracy. For instance, some drivers believe that synthetic motor oil causes your engine to leak because it is slipperier—this 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 #3: You can't switch between synthetic and conventional oil.

Another misconception is that you can’t switch between synthetic and conventional oil. Here is the official notice: it is OK to switch back-and-forth between conventional oil and synthetic oil. No harm done! In addition, motor oils that are labeled as a synthetic blend are already a blend of both conventional and synthetic oil. Always follow the vehicle manufacturer’s recommendation for engine oil.

Myth #4: If your oil is black then you definitely have to change it.

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.

You know what's not an urban legend? Over 19,000 oil changes are performed at Firestone Complete Auto Care every day. That's a lot of happy engines and happy drivers. Visit your nearest Firestone Complete Auto Care oil change location today for a quick oil change and a free 19-point inspection from one of our knowledgeable technicians.

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