6 Of The Best Oil Additives For High Mileage Engines

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Have you had your car or truck for a good number of years? Or are you considering buying a vehicle that has a lot of miles on the engine? If either of these scenarios applies to you, ads for oil additives might have caught your attention. Are these additives actually necessary? We researched this extensively so that you’ll know what oil additives are and which ones might be right for your vehicle.

Oil additives help protect your engine from engine sludge and other harmful buildups. Depending on the type of additive, this is done in one of two ways. Some additives will flush and remove unwanted substances while also coating and lubricating the engine’s internal parts. Others will work to create a chemical reaction within the oil itself, which results in eliminating sludge. We’ve found the following additives to be some of the best on the market today:

  • Mobil 1 High Mileage
  • Slick 50 Recharged
  • Lucas Oil High Mileage Oil Stabilizer
  • Rislone Concentrated Engine Treatment
  • Valvoline Full Synthetic High Mileage with MaxLife Technology
  • Castrol Edge High Mileage

Now that we see some of the better engine oil additives available, we’ll look closer at what each one is best at. You might also have other questions about oil additives in general. Should you use high mileage oil or synthetic? What is considered a “high mileage” engine? Are these additives really necessary? To see what we’ve discovered, read ahead in this post.

A hand in protective glove with oil bottle, 6 Of The Best Oil Additives For High Mileage Engines

Best engine oil additives on the market today

If you’ve shopped for engine oil additives, you may have been a little overwhelmed by the available choices. Here, we break down some of the best ones we’ve found on the market. 

Before adding any additive to your vehicle, consult your owner’s manual. Consulting with a trusted mechanic is also recommended. While using an improper engine oil additive won’t necessarily harm your vehicle, some will work much better than others, depending on your engine type. 

Mobil 1 High Mileage

This brand of engine oil additive works to prevent the five factors that cause engine damage over time. Mobil 1 also helps to protect the engine in extreme temperatures, both internal and external.

To view the Mobil 1 High Mileage oil additive on Amazon, click here.

Slick 50 Recharged

This oil additive is known for revitalizing engine seals so that leaks can be avoided or stopped. Slick 50 Recharged also works to cleanse the engine of unwanted substances, like sludge and rust. 

To view the Slick 50 Recharged oil additive on Amazon, click here.

Lucas Oil High Mileage Oil Stabilizer

Lucas Oil’s additives are great for engines with over 100k miles. This additive is known for increasing the engine’s life and helping to stabilize fuel economy.

To view the Lucas Oil High Mileage Oil Stabilizer on Amazon, click here.

Rislone Concentrated Engine Treatment

Rislones’ additive can be added to your vehicle’s engine at any time. This brand is known for cleaning the engine and giving worn parts extra lubrication. Rislone works to quiet noisy engines and helping to prevent important engine parts from prematurely wearing. 

To view the Rislone Concentrated Engine Treatment on Amazon, click here.

Valvoline Full Synthetic High Mileage with MaxLife Technology

Valvoline boasts of its brand laying down extra layers of lubricant inside the engine. This prevents sludge from building up and also keeps moving parts from getting too hot. This brand is also good at preventing leaks from worn seals and gaskets and helping to eliminate existing ones.

To view Valvoline Full Synthetic High Mileage additive on Amazon, click here.

Castrol Edge High Mileage

Castrol’s engine oil additive is known for increasing the fuel economy on high mileage engines. This product also prevents premature wear from short trips. 

To view the Castrol Edge High Mileage on Amazon, click here.

What is considered a high mileage engine?

For an engine to be considered high mileage, some experts will take into account the make and model of the vehicle. Certain ones, like over-the-road trucks, are engineered to get more road miles.

In general, the automotive industry will deem most engines as “high mileage” when they exceed 75,000 to 100,000. However, when it comes to suggesting oil additives, mileage isn’t the only factor.

The age of the engine is also a consideration. Even with lower mileage, high mileage oil and additives are recommended for engines that are seven years old and up.

Engine of a car

Are oil additives necessary?

As engines age, sludge slowly builds up inside of them. Even with regular oil changes, you won’t eliminate everything that is building up inside of it. Using a recommended oil additive can reduce and remove this harmful buildup.

These additives also work to reduce friction on aging engine parts. This keeps your vehicle’s engine from getting too hot and helps to make the engine last longer. A good oil additive will also help reduce emissions and keep your vehicle’s fuel economy stable. 

Is high mileage oil a gimmick?

With all of the hype and marketing behind most any product, it’s easy to become a little skeptical about a particular product being necessary. In the case of high mileage oil and oil additives, this is not the case.

Engine parts will wear over time. And while nothing lasts forever, these oil additives and high mileage motor oils are proven to keep your engine running for longer than engines without them. While dozens of other factors will determine just how long your vehicle and vehicle’s engine will last, making sure that your internal parts are lubricated is a major one. 

High mileage oil is meant to flush out the unwanted deposits from old oil that might have built up inside of your engine. Combining this type of oil with a proper additive will also help to remove rust and other debris.

Another important reason to use high mileage oil and engine oil additives pertains to the seals inside the engine. Seals and gaskets need to be lubricated so that they’ll last, especially in a scorching hot environment like the inside of a running engine. Over time, these seals will crack, causing slow leaks. Using most any high mileage products will help prevent this from happening and seal up existing leaks.

Should I use high mileage oil or synthetic?

The general rule here is to use the product that best matches the one that you’ve been using for the life of the engine. If you’ve always used synthetic oil and synthetic oil products, it’s recommended to use synthetic additives. And if your engine has always used traditional motor oil, then the additives you use should be suited for that type.

Before adding anything to your vehicle’s engine, check with your owner’s manual or a trusted mechanic. Making sure you have the proper product will ensure a longer life for your engine.

Refueling and pouring oil quality into the engine motor car

In Closing

Engine oil additives are measurably successful in extending the life of your vehicle’s engine. These products will help flush unwanted deposits from the engine and work hard to lubricate all of the internal parts. No matter if you use traditional motor oil or a synthetic brand, you’ll be able to find an additive that’s suited for your high mileage engine.

If you found this post on oil additives helpful, we recommend the following automotive posts:

How Much Does It Cost To Replace Engine Air Filter?

Why Do Cars Need Oil? [and What Happens If You Don’t Change Oil]

Car Won’t Accelerate When Pressing The Gas; What Could Be Wrong?

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