Best High Mileage Oil Additives (For High Mileage Cars)

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Looking for the best high mileage oil additives? This article reviews some of the best options in the market you may want to consider.

It’s no new thing to every driver that having clean oil in an engine plays an important role in guaranteeing an improvement in the engine’s performance. Hence, the oil inside an engine is to be changed quite regularly, after a number of miles, let’s say between 6,000 miles to 10,000 miles.

This regular change is to ensure that what’s inside the engine is only clean oil. But then, motor oils are different; here, we’re not talking about viscosity or brand; instead, we imply to say that the additives used in motor oil formulas differ from one to another.

Apparently, 5w20 oil from two different brands is most likely not to feature the same additives in the formulas. However, regardless of the additives used by motor oil manufacturers, investing in oil additives can be a good decision, especially if you’re driving a high-mileage vehicle.

What is High Mileage Oil Additive?

In the simplest terms, high mileage oil additive refers to a specially formulated formula that is meant to mix with the oil in your engine to ensure a better engine performance, longer protection against wear, and to keep the internal engine components clean at all times.

Already, motor oils include additives in their formulas; however, these aftermarket options tend to guarantee better oil delivery and flow at different temperatures. Of course, these oil additives, also called engine additives, are differently formulated, which means you need to choose carefully.

To make things easier, we’ve provided a buyers’ guide in this article to help you make the best selection for high mileage oil additives. They are called high mileage oil additives because they are meant to be used on vehicles with over 75k miles., otherwise known as high mileage vehicles.

Related Post: Best High Mileage Oil Filters

Types Of Oil Additives

Best High Mileage Oil Additives

Oil additives are simply “supplement” formulas that mix with the engine oil to carry out different functions. There are quite different types of additives you can add to your car’s engine; they are also called oil supplements.

1. Anti-Wear Additives

As the name connotes, this type of oil additives are formulated to prevent wear; they coat the internal engine components and surfaces in a bid to protect them from wear.

2. Viscosity Modifiers

Motor oils are sold and used according to their grades, which is also called “Viscosity.” This type of additive is what to use if you’re not using the actual recommended oil grade for your engine.

For example, if your engine is specified for 5w20 and you’re using 5w30 motor oil, then you should consider this type of oil additive so that the oil would flow seamlessly regardless of the operating temperature.

3. Inhibitors

These are additives that are formulated to inhibit corrosion and rust to prevent chemical breakdown. They neutralize the acids in motor oils, and by that, reduce oxidation.

4. Detergents

This is quite self-explanatory. Detergent oil additives are the ones that are formulated with special detergents to clean the inside of motor engines, to ensure there’s no sludge, dirt, or buildup to prevent or dent the engine’s performance.

5. Anti-foaming

Anti-foaming additives reduce surface tension between air bubbles and engine oil; thus, causing the bubbles to dissipate easily. A motor oil that does not include this additive by default is most likely to produce tiny air bubbles, which can cause loss of oil pressure.

6. Dispersants

Dispersant additives help to prevent sludge buildup and deposition by suspending the solid particles carried by the oil while flowing into the engine.

Best High Mileage Oil Additive

1. Liqui Moly Anti-Friction Oil Treatment

Liqui Moly MoS2 Anti-Friction Engine Treatment | 300 ml | Oil additive | SKU: 2009
  • Motor oil additive - Liqui Moly MoS2 anti-friction (300 ml. Can).Fit Type: Universal
  • Forms High load-bearing film of lubricant on all friction surfaces
  • You will be surprised at how much better your engine sounds and how controlled it will be even at very high RPM
  • Flash point: 181.0 degrees_celsius

If you notice that your engine always makes noise as you drive, this additive could be the ideal solution you need. This is an anti-friction oil treatment additive; its function is to reduce friction and noise inside the engine, and this can lead to significant improvement in engine performance.

The Liqui Moly anti-friction oil additive is a good choice for drivers of high mileage vehicles because it has thick, which would thicken your regular engine oil for better sealing and protection of the core components.


  • Helps in reducing engine noise and friction
  • Good price
  • It is thick and the container is big; so you’d use it for a long time


  • Doesn’t really improve engine performance on all vehicles it’s used on
  • Makes your oil much thicker and dark

2. Prolong Super Lubricants

Prolong Super Lubricants PSL11000 Engine Treatment - 12 oz. , White
  • Includes a Formula with Anti-Friction Metal Treatment Technology
  • Features Engineering Designed to Treat Metal Surfaces of Both Gasoline and Diesel Fueled Engines
  • Offers Molecules that Interact with Metal Surfaces and Chemically Bond to Create a Protective Layer that Reduces Damaging Friction and Heat
  • Offers to Protect the Engine Even when the Motor Oil is Not Yet Fully Circulating
  • Features a Formula Containing No Solid Particles Such as PTFE Resins, 'Molys', Zinc, Copper, or Graphite

This oil treatment formula contained in a 12-oz bottle is one of the best to get for your high mileage vehicle. It is specially formulated with an anti-friction metal treatment technology; hence, this additive is able to treat your engine’s metallic surfaces.

Related Post: Can i Use 5w30 Instead of 5w20 Oil?

Interestingly, this additive works for gasoline and diesel engines. The formula also includes molecules that coat the metallic surfaces of your engine to protect against wear, friction, and heat. Furthermore, the formula does not contain solid particles like PTFE Resins, Zinc, etc.


  • Available in different containers
  • Unbeatable price
  • Loved by most of its users


  • An Amazon user allege that the new formula is watery (less thick than the previous)

3. Archoil AR9100 Oil Additive

Archoil AR9100 Oil Additive (16oz) for All Vehicles - Powerstroke Cold Starts, Eliminates Injector Problems
  • 16oz AR9100 Friction Modifier - treats one Power Stroke
  • Fixes 6.0L and 7.3L Power Stroke cold start injector problems
  • Reduces wear and extends component life
  • Reduces engine noise, vibration and heat
  • For all diesel and gasoline engines, gearboxes, hydraulics, differentials and power steering systems

The Archoil AR9100 oil additive is one of the best to use on old vehicles. First, it comes in a big container and the formula is well-made. This additive is a friction modifier, which means it reduces friction inside the engine, which also would stop the engine from making noise when you drive.

Also, considering the container size, this is a good buy for the price. Furthermore, it works on both diesel and gasoline engines, and you can add it to any type of motor oil you’re using. The formula contains Zinc, which typically helps to prevent corrosion and rust.


  • Comes in a big container – 16oz
  • Works for gasoline and gasoline engines
  • Makes old engines function smoother than before


  • This additive is not very effective in hot climates
  • Thickens when you store it for too long in a cold storage

4. Hot Shot’s Secret Original Stiction Eliminator

Hot Shot's Secret Original Stiction Eliminator 32 Fluid Ounce Bottle
  • Improved Power, Improved Compression
  • Removed Engine Deposits, Seals Rings Better
  • Neutralized Harmful Engine Acids, Reduced Frictional Drag
  • Prevent Excessive Wear
  • Reduced Lifter and Valve Noise

Here’s another impressive oil additive to use on high mileage engines. This additive helps to reduce high mileage engine wear, friction, and delivers maximum protection against wear. It also works to remove deposits from inside the engine and stabilizes oil pressure.

The Hot Shot’s Secret Original Stiction Eliminator is made with an advanced formula. It is capable of restoring failing injectors. Furthermore, this additive is a blend of synthetic cleaner and a proprietary carbon nano lubricant. It stands out among others at an affordable price.


  • The formula comprises proprietary ingredients
  • Works on virtually all engines
  • Best for high mileage engines with fuel injector issues
  • Reduces emissions


  • Some Amazon users had a bad experience with this product

5. LUCAS 10001 Heavy Duty Oil Stabilizer

Lucas Oil 10001 Heavy Duty Oil Stabilizer - 1 Quart
  • The world’s #1 oil additive
  • Formulated with 100% petroleum
  • Suitable for new engines
  • Multi-use versatility
  • Trusted by pros to keep engines running smoothly under the most demanding conditions

As an oil stabilizer, this additive helps the motor oil in your engine to flow evenly. In addition, it helps to properly lubricate the internal engine parts to reduce noise and mitigate overheating. Also, this oil additive coats the engine components in a bid to protect them from wear.

Related Post: Can You Mix 5w20 and 5w30?

It works best in vehicles with manual transmissions and differentials. This additive is 100% made from petroleum, and it really works for the need. You can use Lucas 10001 on any type of engine; it helps to prevent leaks, too.


  • Extends engine oil life
  • Deliver maximal protection
  • Reduces heat and friction
  • Good for old cars


  • Doesn’t work well on new cars that use lighter oils like 5w30

6. REV X High Performance Oil Additive

REV X High Performance Oil Additive - 4 fl. oz. Bottle
  • 4 fl. oz. bottle of REV X High Performance Oil Additive. Will treat up to 6 quarts of oil per bottle.
  • Quiets engine noise while cleaning harmful deposits, varnish and sludge in all engines. Reduces friction by creating a microscopic friction reduction layer on all treated components to reach areas standard oils can not.
  • Removes stiction, common in HEUI Injectors, without using harmful and dangerous chemical strippers. For HEUI Injector Stiction, it is recommended to use two 4 fl. oz. bottles.
  • Extends the service life of all synthetic, semi-synthetic, and mineral based oils providing a reduction of wear of all treated engine components.
  • Greatly improves or eliminates cold start issues in all engines. Works great in all gas powered engines.

As we continue with this list, here’s another impressive additive you should consider using for your high mileage old vehicle. This oil additive is powerful and works on truck engines too. Its formula does not include dangerous chemical cleaners that may react with the metallic surfaces of your engine.

However, this oil additive helps to clean out sludge, dirt, and carbon deposits that are inside the engine. It also helps to reduce engine noise by reducing friction and improving oil flow. The Rev X oil additive works with different kinds of motor oils, including full synthetic oils and synthetic blends.


  • Cleans the engine very well
  • Delivers maximum seal protection
  • Increases engine oil lifespan


  • It is expensive

7. Sea Foam SF-16 Motor Treatment

Sea Foam SF-16 Motor Treatment - 16 oz. , white
  • Specs: Sea Foam Motor Treatment, Notes: Cleans fuel injector and carburetor passageways, Cleans intake valve and chamber deposits, For all motor oils, conventional and synthetic, For any gas or diesel fuel blend, For cleaning, use 2 or more ounces per gallon the more you add to fuel, the better it cleans, For regular fuel system maintenance, add 1 ounce per gallon of fuel, Lubricates upper cylinders, Pour Sea Foam in your fuel tank to clean and lubricate your entire fuel system
  • Replaces OEM Numbers: Sea Foam: SF16
  • 1-year warranty protects you after your purchase. We're confident that our products will work flawlessly once installed in your vehicle. But in a rare case that it does not, we'll replace it anytime within one year of your order. If you have a problem, we will take every step to assist you, contact us for a replacement.
  • 100% New Aftermarket Sea Foam Motor Treatment built to meet OEM specifications
  • 100 percent pure petroleum

Sea Foam is a notable company that produces auto care products, and this oil additive from the brand is one of the best to use. It is made from 100% petroleum product and it is EPA certified. The Sea Foam SF-16 Motor Treatment is an additive that cleans old engines.

This product also tunes up old engines for them to perform better. It removes varnish deposits and other containment from the engine, which can lead to a significant increase in performance and fuel economy.

Read Also: Negative Effects of Seafoam


  • Reputable brand
  • Good price
  • Cleans the engine thoroughly
  • Makes old engines run better


  • Does not effectively protect against wear

8. Hy-Per Lube HPL201-3PK

Rislone Hy-Per Lube HPL201-3PK High Performance Oil Supplement - 32 oz, (Pack of 3)
  • Provides complete protection against start-up wear by leaving a protective film on all internal engine parts, even if your engine has not been running for long periods of time
  • When used in high mileage engines, Hy-Per Lube will help restore performance and improve fuel economy by better sealing piston rings and valve guides
  • Hy-Per Lube provides added protection between oil changes and will extend the life of your oil by up to 50
  • Rislone Hy-per Lube Oil Supplement, 32oz Pack of 3 reduces foam and helps extend the life of your engine and also reduces gear box and transmission temperatures
  • Rislone Hy-per Lube Oil Supplement will reduce lifter and drive train noise

Hy-Per Lube HPL201-3PK is a premium oil supplement made with an advanced formula. It is best for high mileage engines, and it works for all kinds of motor engines. This additive protects your engine against start-up wear; it does this by placing a protective coat on all the internal engine parts.

In high mileage engines, this additive will trigger a significant improvement in performance and fuel economy. It also seals the piston rings and valve guides to prevent leaks. This supplement also reduces friction and engine noise. It is one of the best you can buy now.


  • Increases oil life
  • Works on both new and old engines
  • Coats the internal engine parts against wear


  • It is very thick

Benefits Of Using High Mileage Oil Additives

The main benefit of using oil additives is to achieve better performance and improved fuel economy.

Notwithstanding, high mileage oil additives include detergents and non-harmful cleaning agents to remove dirt from inside your engine, which can lead to improved performance, and also cause the engine to last longer.

Furthermore, oil additives coat the engine metal surfaces with a protective film to protect against wear. Understandably, most of these benefits mentioned here are what most motor oils promise to offer; but, that notwithstanding, oil additives, in general, help engine oils to perform their functions perfectly.

Not to forget, oil additives also offer seal protections to prevent leaks and overheating.

Frequently Asked Questions

1. Should I Use Oil Additives On New Engines?

While there is nothing wrong with using oil additives on new engines, it is not advisable to do such. Instead, you should use full synthetic oils for the new engine; they are typically formulated with advanced additives that protect and clean the engine very well.

2. How Do You Add Oil Additives To Engines?

Oil additives are mixed with engine oils and poured into the engine. So, how often you should add oil additives depends on your oil change intervals.

3. Can Oil Additives Harm My Engine

No, oil additives cannot basically hurt your engine; however, you need to be careful when choosing the one to use for your engine. Some oil additives are universal, where there are some that are meant to serve specific purposes; you just have to pick the right one for your vehicle.

4. Do Oil Additives Improve Engine Performance?

For high mileage engines, oil additives can trigger significant improvement in engine performance. These additives try to clean out every dirt inside the engine, and as such, you will experience a better and improved engine performance.

Related Post: Can Seafoam Damage Car Engine?


These oil additives really work on high mileage engines; they contain powerful cleaning agents to clean out the containments that are affecting your engine’s performance. Also, they coat the engine parts to prevent them from wearing.

While all the oil additives mentioned above are good and effective, the LUCAS 10001 Heavy Duty Oil Stabilizer is our best pick. It is very affordable, comes in a sizable container, and works perfectly on old cars with high mileage. You can get these additives from Amazon or local stores.

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