There are quite a few myths pertaining to motor oil, recycled oils and synthetic oils. In order to help set things straight, we’ve addressed and debunked a lot of the common Motor Oil Myths below.

General Motor Oil Myths

MYTH: Changing your vehicle's motor oil yourself or using a certain brand voids your manufacturer's warranty.

Changing your vehicle's motor oil yourself or using a different brand of oil from your manufacturer's factory fill will not void the warranty. As long as the motor oil being used meets the manufacturer's standards required for the vehicle (e.g., viscosity grade, type), as provided in the owner’s manual the warranty cannot be considered void.

MYTH: All oil additives are the same.

Not true. Some additives contain different formulations to affect certain parts of the engine differently than other additives.

MYTH: All brands of motor oil basically are the same.

That’s false. Base oils, additives, etc., can be different from one brand to the next.

MYTH: Switching motor oil brands is harmful to my engine.

No. Switching brands is not harmful to your engine as long as you choose an oil marked with the API donut of the same level, e.g., API SN. Motor oil manufacturers must meet minimum industry standards for performance and compatibility of the API mark. However, make sure you follow the recommendations provided in your owner's manual for viscosity and API category. You may give up enhanced performance if you switch from synthetic or high mileage to conventional oil.

MYTH: When motor oil becomes dark, that means it's time to change it.

This is not true. You cannot determine the life of motor oil by looking at its appearance since it may change color for several reasons. To ensure the best quality product, the best oil change tip is to always follow your vehicle’s owner's manual guidelines for oil change intervals.

MYTH: You don’t have to change your oil filter every time you change your oil.

Valvoline recommends changing your oil filter each and every time you change your oil. This eliminates any risk of contaminants trapped by the oil filter, such as dirt, from re-entering the oil. Consult your vehicle’s owner’s manual for your manufacturer’s recommendation.

MYTH: Bulk oil is a different (lower) quality than bottled motor oil.

Valvoline’s bulk oil is the exact same oil that is bottled and sold at retail locations.

MYTH: Oil never wears out – it only gets dirty.

False. Oil additives weaken as the engine oil is used.

MYTH: Thicker oil is better.

Thicker motor oil can be better for older engines in which engine parts have worn down over the years. However, it is recommended to always stick with the viscosity weight recommended by the manufacturer of the particular engine. The oil “thickness” (viscosity-temperature profile) is selected by the manufacturer to protect moving parts with specific design and surface roughness from excessive contact.

MYTH: The “w” stands for weight.

Actually, the “w” stands for winter, and the numbers that appear refer to the oil’s viscosity at both low and high temperatures.

MYTH: Long driving = hard driving

This is not always the case. Hard driving pertains to high and/or consistent changes of RPMs (stop-and-go driving), pulling or towing. It can also be dependent upon the geographic area where you drive.

MYTH: You cannot use motor oil in a car with manual transmission.

This depends. It’s important to follow your owner’s manual for requirements and correct fluids to use in your manual transmission.