Featured image for "Best Synthetic Oil For Ford 6.7 Diesel" blog post. Ford F-250 truck.

Best Synthetic Oil For Ford 6.7 Diesel

You’ve spent a lot of money on your Ford* truck. You don’t want it to have to be in the shop constantly due to a lack of proper maintenance. That’s simply money down the drain. Using the finest synthetic engine oil for diesel engines is a straightforward technique to decrease downtime and maintenance expenses.

The kind of engine oil you use to safeguard your diesel engine is the first and most crucial decision you’ll make. This blog post will help you pick the best synthetic oil for Ford* 6.7 diesel engines. We’ll offer facts that will give you better knowledge and a clearer explanation of why synthetic engine oils are the best choice for your Ford* 6.7 diesel engine.

What is the Best Oil for a 6.7 Powerstroke?

To get right to the point, the best synthetic oil for Ford* 6.7 diesel engines is AMSOIL. For a 6.7 powerstroke engine, AMSOIL recommends Signature Series Max-Duty Synthetic Diesel Oil 10W-30 for normal usage (above -18 degrees F) and 5W-40 for severe operating conditions. If biodiesel fuel blends are used, the use of 15W-40 (above -7 degrees F) or 5W-40 (above -29 degrees F) oil is recommended.

For a less confusing system, 0W-40 is the ideal all-temperature viscosity to use for this particular engine type.

Another excellent line of diesel engine oils from AMSOIL is their Heavy-Duty Synthetic Diesel Engine Oil line. The same recommended viscosities mentioned above also apply for this line of synthetic diesel engine oils (10W-30, 5W-40, and 15W-40.)

By the way, if you’re also looking for the best oil filtyer for 6.7 powerstroke engines, we suggest AMSOIL’s #57151-EA WIX Oil Filters.

Let’s get into the true purpose of an engine oil and why synthetics are superior to conventional oils.

What does engine oil do? Quality motor oil protects vital engine components. It must cool the engine, create a protective coating to decrease friction and excessive wear, and neutralize toxic acids generated and present in a diesel engine. It must defend, last, and execute its function for a long time. The oil should keep the engine clean, resist extreme temperatures, and not evaporate. During cold dry starts, this oil must immediately reach engine components to prevent wear.

Note that 80% of engine wear happens during cold dry starts. This knowledge immediately narrows your options since just a few engine oils safeguard your engine during cold dry starts.

AMSOIL Signature Series Max-Duty Synthetic Diesel Oil 15W-40.
AMSOIL Signature Series Max-Duty Synthetic Diesel Oil 15W-40

Not All Base Oil Stocks Are Equal

Diesel engine oil blenders have options. They may opt to create a low-cost diesel engine oil that fulfills industry requirements. They alternatively may opt to produce an oil that surpasses industry requirements and gives untold advantages and performance regardless of the cost of the components.

Diesel ad 3.

If you want to safeguard your Ford* truck and keep it out of the shop, you must carefully choose the kind of oil you will use. A diesel engine oil that barely satisfies minimal specifications and sells at the lowest price is unlikely to offer the protection required to keep a hardworking diesel engine running for a long time.

We need to look at the components of high-quality synthetic oil in more detail to understand why there are variations between low-cost oil and high-performance oil that initially takes a lot larger investment but inevitably is the lowest cost engine oil.

AMSOIL Signature Series Max-Duty Synthetic Diesel Oil 5W-40.
AMSOIL Signature Series Max-Duty Synthetic Diesel Oil 5W-40

Base stock oils are the building blocks of any motor oil or lubricant. The manufacturer’s choice of base oil will affect the oil’s performance and advantages. A lubricant’s base oil is thus essential. There are two base oils. Mineral or petroleum base stock oils are available, as well as synthetic base stock oils.

The first fundamental distinction between mineral and synthetic base stock oils is their molecular structure. A mineral oil’s molecular structure is uneven, with varying-sized molecules. Their varying molecular sizes generate uneven flow. Uneven flowability causes undesirable fluid friction.

During cold dry starts, the irregular-sized molecules tend to be thick and flow with too much resistance. They take too long to reach vital engine components, creating extra wear.

Diesel banner ad 1.

Any friction in an engine can eventually cause undesired heat and other complications. When a lubricant contains heat, temperatures rise and component wear rises.

AMSOIL Signature Series Max-Duty Synthetic Diesel Oil 0W-40.
AMSOIL Signature Series Max-Duty Synthetic Diesel Oil 0W-40

Understand that there is a limit to the refining of a mineral base oil. The refining procedure attempts to remove undesired byproducts, but not all of them can be removed. The leftover byproducts generate sludge, varnish, and other undesirable deposits in engine oils.

Yes, selecting petroleum or mineral base stocks for diesel engine oil manufacturing has accounting considerations. Based on their pricing, these oils are sufficient. Consider the tradeoffs. Mineral oils, for example, perform poorly in cold temperatures owing to wax concentration in base stocks. Their average thermal stability rating suggests that while working at high temperatures, part of the oil may burn off and evaporate, causing oil consumption and sludge development.

Petroleum-based or traditional diesel oils are adequate for light-duty applications and their cheap cost is justified.

These petroleum or standard base stock oils are inadequate for heavy-duty truck operators whose equipment is subjected to more rigorous long-term operation. In many circumstances, these light-duty oils appear to be the standard.

Synthetic base stock oils are an obvious choice for the open-minded thinker trying to safeguard their investment and enhance performance.

Synthetics have a different molecular structure than mineral base oils. These synthetic base stocks are uniform in size and molecular structure. Because they are the same size, they provide little to no friction. This is vital for a diesel engine that has been resting for a long period.

As noted before, 80% of all engine wear happens during cold dry starts. Synthetic oils nearly eliminate undesirable wear. They get to crucial engine components rapidly. Synthetics are polar in nature. They prefer to cling to engine parts. A tenacious coating of synthetic oil remains after a motor has been shut down owing to its polarity or attraction to metal surfaces.

Synthetic base stocks are also different from mineral base stocks in that they are man-made and do not include undesired byproducts. Synthetics can also endure significantly greater temperatures. They have better thermal stability. Synthetic oils use less oil than normal petroleum base oils. They have superior flowability in cold temperatures when compared to mineral oils.

Now that we know that synthetic base oils outperform traditional base oils, we can focus on finding the best recommended oil for 6.7 powerstroke engines.

Diesel Additives for Maximum Performance

Diesel engines are difficult to lubricate. When creating a diesel engine oil that can efficiently preserve hard working engine components in a variety of operating settings, several factors must be addressed. The first challenge with a diesel engine is neutralizing the corrosive acids that generate during operation.

A detergent/dispersant chemical is used to combat acidity in diesel engines. On each diesel motor oil technical data sheet, you will see something called Total Base Number, or TBN. This figure indicates an oil’s acid neutralization capabilities. Most low-cost diesel engine oils have TBN values of 5 to 8. A TBN of 10+ indicates a high-quality synthetic diesel oil. The higher the number, the better the oil neutralizes corrosive acids.

Diesel banner ad 2.

After then, scientists must figure out how to make this acid fighting chemistry endure and give acid neutralizing protection for a long time. Retention of TBN is key. The longer TBN remains constant, the longer it can fight acid. Cheaper mineral-based diesel engine oils don’t have the TBN retention needed for a hardworking diesel engine. If an oil can’t properly neutralize acids, anticipate a negative vicious cycle of oil deterioration.

AMSOIL Signature Series Max-Duty Synthetic Diesel Oil 10W-30.
AMSOIL Signature Series Max-Duty Synthetic Diesel Oil 10W-30

Engine wear and oil deterioration accelerate when a diesel engine quits neutralizing acid. If this deteriorated oil is left in the engine, catastrophic failure may result. If an owner of a diesel vehicle insists on using low-cost mineral oil, regular oil changes are required.

If you want to discover more about an engine oil that has excellent TBN retention, choose an AMSOIL 100% pure synthetic heavy duty diesel motor oil. AMSOIL synthetic diesel oils have been independently tested and shown to have TBN retention considerably beyond industry norms.

Superior TBN retention needs only top-tier detergents and dispersants. These additives initially cost more, but they stay significantly longer, provide amazing TBN retention, and most importantly, quickly neutralize acids. They are designed for high duty diesel engines. These synthetics are top notch.

For heavy duty diesel vehicles, only these oils should be considered. Why invest lots of money on a vehicle just to utilize low-grade conventional diesel oils? Match lubricant quality to vehicle quality, and your vehicle will outlive others who’s owners assume cheap oils can do the job. That way of thinking is illogical.

The next issue is friction. The  long service life of an engine depends on reducing friction. If there’s a way to reduce friction, it’s worth looking into.

AMSOIL Heavy-Duty Synthetic Diesel Oil 15W-40.
AMSOIL Heavy-Duty Synthetic Diesel Oil 15W-40

Mineral base oils contain variable sized molecules, as noted before when addressing base stocks. Smaller molecules cause fluid friction. By using mineral oils, you’ve inherited unnecessary friction from day one. That is, you begin with a minus.

While lubricant producers have found methods to minimize fluid friction, why not start with an oil that reduces fluid friction from the get go? Like synthetics! Synthetics start on the good side, not the negative. Synthetic base oils inherently reduce friction.

Specialized friction modifiers are applied to increase a synthetic’s inherent ability to minimize friction.

High performance synthetic diesel engine oils are made with just the best friction modifiers. These unusual additives have a significant affinity for metal surfaces. These friction modifiers will considerably benefit engine components when added to synthetic diesel oil.

Friction modifiers decrease friction further, resulting in lower temperatures, reduced metal wear, and longer engine and oil life. Using a quality synthetic engine oil reduces friction, as shown by oil analysis. Metal wear will be reduced as per oil analysis.

Using a quality synthetic diesel engine oil reduces friction in an engine, which improves fuel efficiency. Synthetic oils minimize friction, enabling engines to function more effectively and therefore using less fuel. Also, reducing friction increases an engine’s output.

Anti-wear agents are the next additions in a quality synthetic diesel engine oil. Anti-wear compounds chemically react with metal surfaces to prevent them from rubbing. They act in conjunction with friction modifiers to decrease early wear and assist with enduring high pressures.

AMSOIL Heavy-Duty Synthetic Diesel Oil 5W-40.
AMSOIL Heavy-Duty Synthetic Diesel Oil 5W-40

Anti-wear compounds keep metals from touching.

A diesel engine’s moisture formation potential is considerable. Rust and corrosion inhibitors are used to protect engine components from dampness. Chemical bonds protect metal surfaces from moisture and acids, preventing rust and corrosion. This chemical connection prevents moisture and acids from penetrating the metal surfaces.

Foaming is another issue with diesel engines. Foam insulates. It may trap heat generated by a running engine. Temperatures may spike inside a motor if foam builds up. Anti-foaming additives are frequently added to lubricants to assist in reducing foaming. A good anti-foam ingredient used correctly may lower operating temperatures by 20 to 50°F. The anti-foam ingredient disperses the foam, releasing the contained heat.

An oiliness additive is another fascinating component found in premium synthetic diesel oil. This unique ingredient enables the oil to physically permeate the metal beneath, providing excellent lubrication.

VI improver is the last but most important component in a multi viscosity diesel engine oil. This additive is coiled. Cold compresses the spring. The coil expands at high temperatures. A lot of shearing happens within an engine. Imagine shearing as a pair of fast-moving scissors.

AMSOIL Heavy-Duty Synthetic Diesel Oil 10W-30.
AMSOIL Heavy-Duty Synthetic Diesel Oil 10W-30

Low-cost viscosity index improver additives are used in low-cost traditional diesel oils. These VI improvers shred easily. These VI improver’s coils are simply cut using our hypothetical scissors.

Such a viscosity index improver additive breaks down as an oil loses viscosity. That is, a 15W40 oil shears to 15W30, then 15W20, and so on. Oil will not reach the necessary 40 weight after shearing. Shear stable viscosity index improver additives are included in high grade heavy duty synthetic diesel oils. They withstand shearing well and can last a long time without losing viscosity over long drain intervals.

For example, AMSOIL Signature Series Diesel Engine Oil is shear stable and demonstrates little viscosity loss in independent testing. The ASTM D-5481 High Temperature/High Shear Viscosity Test confirmed its exceptional shear stability. It outperformed all conventional diesel oils.

Antioxidants are the last addition in a better diesel engine oil. We already know that synthetic base oils are thermally stable. They are heat and oxidation resistant. Adding an antioxidant to a diesel engine oil’s composition improves its oxidation resistance. These oxidation inhibitors assist in avoiding sludge, carbon, and varnish buildup.

Mineral diesel oils are more prone to oxidation. When oxidation happens in a diesel engine, deposits form and the oil thickens, reducing oil life causing needless engine wear.

Choosing the best synthetic diesel engine oil with the greatest oxidation inhibitors gives your engine the double protection it needs for extended drain intervals and long service life.

So, What is the Best Synthetic Oil For Ford* 6.7 Diesel?

What is the best oil for a 6.7 powerstroke enginet? We’ve covered a lot of ground comparing mineral and synthetic oils. We’ve attempted to give a distinct viewpoint or philosophical idea to help you make an educated decision. It’s not easy to change the status quo. And if you’re in business and your life relies on keeping your diesel vehicle out of the shop and producing money, then why not really consider an alternative?

If that alternative can benefit your vehicle more, it’s worth considering. Ask yourself this. What’s more costly, removing an engine from service and rebuilding it? Or buying the finest synthetic diesel engine oil? Is it worth it to save money on oil instead of spending more money on synthetic engine oil that lasts 2 to 3 times as long? In the end, which gives you the highest value or return on your investment?

Whether you’re wondering what the ideal 2019 Ford* F250 6.7 diesel oil type is or simply desire to use the finest diesel engine oil possible regardless of your diesel vehicle type, we sincerely hope you choose AMSOIL!

AMSOIL synthetic diesel engine lubricants have repeatedly shown to be the greatest value-added lubricants. AMSOIL has been the leader in synthetic lubricants for almost 45 years.

*All trademarked names and images are the property of their respective owners and may be registered marks in some countries. No affiliation or endorsement claim, express or implied, is made by their use. All products advertised here are developed by AMSOIL for use in the applications shown.