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Marks Tips

Mark's Tips: Do Oil Additives Really Work?

5 minute read

Marks Tips

Many of you reading this have already performed a DIY oil change on your vehicle(s) multiple times. You’re well versed in choosing what grade of oil your car requires at a certain climate (e.g. 5w-30), how much oil you need, and perhaps even have a trusted high-flow funnel that allows you to pour gallon jugs without pausing every 5 seconds, overflowing your funnel and blanketing your valve cover with fresh oil (we’ve all been there…). You’ve used different brands, had to distinguish the difference between whether your car requires regular or synthetic oil, or perhaps your model even calls for a type of synthetic blend.

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How do oil additives work?

But what about oil additives? What are they? Are they necessary? And do I really need them to protect my engine for years to come?

Simply put, oil additives are essential for your engine to run and perform at its optimal level. Without them, your engine would wear down too quickly, eventually knocking and shuddering its way into a seized-up, unusable mess. Your car’s lifespan would not only be halved, but would run only a fraction of how long it should if additives weren’t in the equation.

So, if this is true, how are modern vehicles often able to surpass 400k+ miles? Well, every major oil available on the market goes through a continuous series of rigorous testing to reach the goal of making engines last longer and longer. That means that, yes, you guessed it, oil additives are already part of the formula for every motor oil available on the market – somewhere in the range of 10 to 20%. Just be sure to choose the correct grade your vehicle requires.

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Are oil additives bad for your engine?

Oil additives consist of numerous chemical compounds, depending on the vehicle application. Common ingredients include detergents, antioxidants (cars like staying healthy, too), and other compounds designed to eliminate friction as efficiently as possible.

However, since standard motor oils already contain additives, most vehicle manufacturers don’t specify that an additional aftermarket additive is beneficial to the longevity of an engine. But there are additional studies performed by third parties that make claims of extending the engine’s life, gaining power, reducing wear and improving fuel economy, most notably if the engine has done a high mileage.

If you do decide to go down the aftermarket route, supplementing your engine at its next oil change, we recommend first and foremost to look for any disclaimer on the oil additive bottle that indicates it could void your vehicle warranty, or that it’s warranty safe. If the fine print on the bottle has no mention of vehicle warranty, you may want to play it safe to search for a product that does.

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Read the oil additives small print

Although the choice to use supplemental oil additives is not always black and white, there are certain reasons one could benefit most. These include:

  • Your car’s warranty: first and foremost, nobody dreams of voiding their vehicle’s warranty and the nightmares that follow. Check the bottle to make sure the additive won’t affect your engine negatively and void your warranty. This could also depend on what the manufacturer states as being safe.
  • Your car’s age and milage: this is one of the bigger reasons an engine could benefit from an additive. Some engine oils are even marketed as “high mileage” oils, which contain additives specifically for this purpose.
  • If you change your oil yourself (referencing Haynes, of course): changing oil on your own means that you get to check the dipstick yourself and prevent overfilling. Also, most shops are interested in doing an oil change as quickly as possible and moving on to the next customer, therefore are not always interested in taking the time to fill your car with an aftermarket additive they didn’t research ahead of time. Haynes will more than likely have an online or print manual for your vehicle, so check our website to see if we cover your year and model to get started on your next proper oil change.

There are many different types of aftermarket additives, formulated for different purposes and applications. These could very well improve your preventative maintenance habits and be beneficial to your engine when continually used. On the contrary, it is not always necessary to use these, depending on the vehicle’s manufacturer and age. Always make sure to check the label on any aftermarket product for your car, minimizing the risk associated with voiding your vehicle’s warranty and more importantly, causing internal engine damage.

The best analogy I can relate to is, some salt is necessary for humans to consume, but ingesting too much of it can clog our arteries. Choose and use wisely!

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