Best Full Synthetic High Mileage Oil (Detailed Reviews)

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What are the best full synthetic high mileage oils? There are quite a lot of controversies about high mileage oils. Many people believe that the term “High Mileage Oil” is marketing jargon, but motor oil brands keep emphasizing that these oils are the real deal for old vehicles.

Well, high mileage oils are alleged to be typically formulated with “special” and “advanced” additives that are beneficial to old engines. What does this mean? It means to say that these oils would offer better sealing and protection against wear for engines that have done over 75,000 miles.

There are pretty many high mileage motor oils in the market; so, we’re putting up this list/review to show you the best ones to go for. Apparently, it is better to stick with full synthetic oils than synthetic blends or conventional oils.

Why Choose Full Synthetic High Mileage Oils?

Regardless of whether you’re buying high mileage oils or “normal” motor oil for your engine, full synthetic oils are recommended because they offer more benefits.

Yes, this is because, fully synthetic oils guarantee longer protection between oil changes, up to 10,000 miles, while synthetic blends or conventional motor oils may only protect up to 5,000 miles in-between oil changes.

More so, it is poised that additives used on full synthetic oils are much better than what’s used for other types of motor oils. That said, full synthetic high mileage motor oils are seemingly the best choice for engines that have put out hundreds of miles.

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Notwithstanding, synthetic blend oils are still good for motor engines, and they are typically cheaper than full synthetic. We won’t recommend conventional oils because they’re not close to synthetic oils in terms of premium protection for old, high-mileage vehicles.

Best Full Synthetic High Mileage Oil

Best Full Synthetic High Mileage Oil

Ensure to note the viscosity and weight of these oils; most of them are 5w30; however, they have 5w20 and 10w40 options. When making your order, ensure to select the viscosity specified for your car engine.

1. Valvoline High Mileage Oil with MaxLife Technology

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As we continue with this list, the Valvoline high mileage is a worthy mention. This high mileage motor oil is made with the brand’s patented MaxLife Technology, which makes it stand out from the rest. You can use this oil on all kinds of vehicles, including trucks and vans; the formula includes premium additives.

Interestingly, this oil includes seal conditioners, and it is available in different grades: 5w20, 5w30, 10w30, and 10w40. It is ideal for cars that have outputted 75,000+ miles on their odometers. The container is strategically designed to ease of use; this oil is the favorite of many car owners.

Main Highlights:

  • Formula includes proprietary MaxLife technology
  • Includes anti-oxidants to prevent oil breakdown
  • Delivers extra wear protection for old engines
  • Extra detergents for effective cleaning


  • The formula includes seal conditioning additives
  • Available in different grades
  • Reputable brand


  • The container doesn’t seem too strong; can get broken easily

2. Mobil 1 Full Synthetic

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Mobil 1 is one of the notable brands that manufacture original auto care products that meet the industry’s specifications.

This 5w20 full synthetic oil from the brand is one of the best in the market. It comes in a 5QT container, and it is recommended for all 5w20 specified engines with over 75,000 miles on the odometer.

This motor oil contains patented additives in its formula, to ensure maximal protection against wear and tear. Mobil 1 5w20 full synthetic high mileage outperforms Mobil’s conventional high mileage oils by guaranteeing maximum protection up to 9,000 miles between oil changes.

Main Highlight:

  • The formula includes seal conditioner
  • Protects up to 9,000 miles in-between oil changes
  • Contains proprietary additives


  • Available in 5QT container, which is big enough for any kind of car
  • Reputable brand
  • Cleans high mileage engines perfectly
  • Improves engine performance for old cars


  • It is expensive

3. Pennzoil Ultra Platinum Full Synthetic

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This full synthetic oil from Pennzoil is one of the best 5w30 high mileage engine oils in the market. It is formulated with “enhanced” additives and contains premium detergents that help to clean out sludge, as well as other deposits that may be found inside the engine.

You can use this oil on high mileage cars and trucks. It also works on vans, in fact, it is a high mileage oil for all kinds of vehicles.

This oil comes in a 5QT container, but there is also a 1QT bottle, and there are 5w20, 10w30, and 0w20 options. Pennzoil is a remarkable motor oil manufacturer, and this high mileage oil is a real deal.

Main Highlights:

  • Includes premium detergents that cleans the engines perfectly
  • Made with high-quality base oil
  • Delivers uncompressed protection against wear and sludge


  • Good price
  • Meets the industry’s standards
  • Works on all kinds of vehicles


  • Does not contain seal conditioner

4. Castrol 03084C Edge

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When looking for the best high mileage full synthetic oils to buy, the Castrol 03084C Edge is an ideal option. It is a full synthetic oil formulated with special additives for high mileage vehicles.

This oil protects against wear, cleans the engine and its components very well, as well as serves you up to 9,000 miles between oil changes.

Related Post: Can You Mix 5w30 and 10w30 Oil?

Castrol 03084C Edge is recommended for all kinds of cars with 5w20, 5w30, 0w20, and 10w30 specifications. It comes in a big 5QT container and meets the industry’s standards for each viscosity grade available. More so, this oil remains function even in extreme temperature conditions.

Main Highlights:

  • Titanium strong for superior engine performance
  • Significantly improves performance of high mileage engines
  • Offers maximum protection for all engine components in-between drain intervals
  • Performs smoothly even in extreme conditions.


  • Arguably the best affordable full synthetic motor oil to buy
  • Made with premium additives
  • Over 15,000 positive feedback from other users
  • Good price


  • Not the best for trucks and vans

5. AmazonBasics Full Synthetic Motor Oil

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You either choose to buy the 5QT option or the 1QT (pack of 5) option. This full synthetic 5w20 motor oil is one of the best you can buy right now. It is made with premium additives and it works on most vehicles where 5w20 is specified. There is also a 5w30 option available on Amazon.

The AmazonBasics brand is one of the reputable brands known to offer original products on the Amazon store. This oil delivers high resistance to viscosity and thermal breakdown. It is ideal for engines that have put up hundreds of thousands of miles already.

Main Highlights:

  • The formula is meant for longer drain intervals
  • Prevents build up that lead to rust and corrosion
  • High resistance to viscosity and thermal breakdown


  • Reduces oil burning in high mileage engines
  • Unbeatable price
  • Works for all vehicles with 5w20 specification
  • Guarantees longer drain intervals


  • You can’t see through the bottle to know how much oil you’ve poured into your engine

How To Choose The Best Full Synthetic High Mileage Motor Oil

You may want to get into the market and make your choices; thus, we’re providing you with a guide on how to choose the best full synthetic oil. It may interest you to know that we also considered these factors to list the products recommended above.

Related Post: Will Synthetic Oil Degrade With Time?

1. Brand/Manufacturer

It is really important to check motor oils based on brands. There are brands notable for using patented formulas, and as such, their oils typically offer more benefits to old and new engines.

When getting a high mileage oil, you should focus on the oil that offers maximum protection and guarantees longer drain intervals. Some top brands include Amosil, Mobil 1, Valvoline, Pennzoil, and Castrol.

2. Viscosity Grade

The viscosity grade of oils is an important factor to consider. It is not advisable to use an oil with lower viscosity than what’s specified for your engine. In the same way, it is not advisable to use an oil with a higher viscosity than what’s specified.

That said, you need an oil with the same viscosity grade as specified for your engine. Oil grades are indicated with 5w20, 10w40, and other similar indications. Check your owner’s manual for the correct grade to use.

Frequently Asked Questions

1. Are High Mileage Oils Good For New Vehicles?

Practically, you can use any type of motor oil for your engine, whether it’s an old car or a new one. But then, it is advisable not to use high mileage oils on new engines; instead, use “normal” synthetic motor oils, while ensuring you stick to the appropriate viscosity for your engine.

2. Are Synthetic Blends Any Good?

Yes, high mileage synthetic blend motor oils are good and recommended, but they do not offer the same benefits as full synthetic oils. Also, using synthetic blends would imply changing oils sooner than your presumed intervals.

3. Where Can I Buy High Mileage Oils?

You can purchase these oils from Amazon or other online stores that sell auto gears and products. Notwithstanding, you can also find them on local offline stores that sell auto products.


These full synthetic high mileage oils are made with premium additives and they are best for old engines with hundreds of thousands of miles.

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