Busted – 5 Motor Oil Myths

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Busted – 5 Motor Oil Myths

Motor Oil Myths Abound – Here are some facts: You Decide

Facts Over Myths

We get phone calls from customers who “read something on the internet” or “heard something somewhere” about motor oils that indicate a lack of the facts. There are “armchair tribologists” who, while mean well, spread myths about motor oils. Here’s a summary of a recent AMSOIL blog article about five of these myths:

Myth #1: Motor Oil Must Be Changed Once It Has Turned Black

Fact: Not necessarily. In many diesel applications, the oil may turn black immediately after changing it. Detergent and dispersant additives hold contaminates in suspension and prevent them from adhering to engine parts, which can turn the oil black. Motor oil that has turned black can be a sign that the additives are doing their job. If you really want to know the condition of the oil, used oil analysis will tell you precisely when the oil needs to be changed. This usually cannot be determined visually. Here is a post that explains why motor oil turns black and whether that signals the time for a change.

Myth #2: You Must Change Oil Every 3,000 Miles (4,800 km)

Fact:  This myth emanated from quick-lube chains many years ago to keep customers coming back. Some oils when this myth started were of low quality; however, today motor oil and engine technology are far more advanced. Original equipment manufacturers (OEMs) today recommend much longer oil-change intervals, some up to 10,000 miles (16,000 km) and longer. AMSOIL Signature Series can last up to 25,000 miles (40,000 km) or one year. For more facts about the 3,000-mile oil-change myth, click here.


Myth #3: You Can’t Mix Synthetic and Conventional Oil

Fact: Conventional and synthetic motor oils have the same basic components: base oils and additives. Even though base oils and additives in synthetic oil are superior to their conventional counterparts, they can be safely mixed. Many years ago some oil companies marketed  synthetic motor oils that were NOT compatible with conventional oils, but they were soon taken off the market: that created issues when a customer had to add a quart of oil. Therefore, today synthetic and conventional oils can be mixed. Remember, though, when mixing the two, the lower quality oil limits the performance of the synthetic oil to that of the conventional oil. Here’s an article on whether it’s safe to mix synthetic and conventional oil.

Myth #4: Once You Switch to Synthetic Oil, You Can’t Go Back

Fact: Since the two oils are compatible, it is perfectly safe to switch back. The question we have is why? After using a synthetic motor oil with improved benefits and performance criteria, why would you switch back?

Myth #5: Synthetic Oil Causes Engines to Leak Oil

Fact: Bottom line, a synthetic oil may find a leak but not create it. Engines that have not been maintained properly can have cracked and worn seals that have sludge and deposits masking the worn or broken seals. Improved detergents in synthetics can sometimes remove these “false seals” of dirt and sludge and expose the worn seals. A good synthetic oil, like AMSOIL, conditions seals to help them remain pliable to prevent leaks. Solution: use a quality synthetic motor oil before seals reach that condition.

If you want to read the entire blog from AMSOIL in detail, click here.

Click here for the data sheet for AMSOIL Signature Series Synthetic Motor Oil.

Any comments or questions, give us a call at 800.745.5055 or send us an email at [email protected] .