What’s The Best Synthetic Motor Oil?

Want the best synthetic oil for your engine? Many companies say they have the best, but we offer proof.

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AMSOIL Synthetic Motor Oil
February 19, 2020

The short answer? We think AMSOIL Signature Series Synthetic Motor Oil is the best synthetic motor oil. Now here’s the proof.

AMSOIL was founded on innovation. Company founder Al Amatuzio was commercially selling synthetic oil by 1968. Four years later, he achieved another milestone when AMSOIL Synthetic Motor Oil became the world’s first synthetic oil to meet API requirements.

By ignoring conventionally accepted limitations, we set the benchmark for performance.

Signature Series: The Best Synthetic Oil You Say?

Signature Series is not only the best synthetic oil we have ever made, it’s better than any competitive oil we’ve tested. Over-engineered? Perfect.

Protects Against Engine Wear

AMSOIL fights wear

Signature Series develops a strong fluid film that keeps metal surfaces separated, while its robust anti-wear additives further reduce wear in metal-to-metal contact regions for maximum engine life.

Vs. Low-Speed Pre-Ignition (LSPI)


We armed Signature Series with an advanced detergent system that protects against harmful deposits and low-speed pre-ignition (LSPI).

Protects Turbos

AMSOIL, conventional vs. synthetic oil, turbo, turbo coking

Its inherently stable formulation resists oxidation and neutralizes acids. This makes Signature Series uniquely capable of protecting against deposits common to high-temperature engine environments.

This is particularly important since more vehicles today than ever leave the assembly line with turbochargers under the hood.

Battles Sludge

signature series sludge

Engine failures due to sludge are often caused by a plugged pick-up tube screen or clogged oil passages.

Signature Series contains potent detergent and dispersant additives that help prevent sludge. It keeps engines clean to help keep the oil flowing to critical parts.

Reduces Top-offs

signature series keeps valves clean

Signature Series has a uniform molecular structure that limits evaporation and keeps it where it’s needed most – protecting your engine. As a result, it helps reduce oil consumption.

That not only helps keep the engine clean, it reduces the amount of top-off oil you need to add between oil changes. As the graph above shows, it’s the best synthetic oil of those tested.

The Best Synthetic Oil Must Keep It Together

signature series fights viscosity breakdown

Signature Series features superior thermal durability that resists breakdown better than conventional and synthetic motor oils.

This means the oil maintains viscosity better, which translates into reliable wear protection and long engine life.

Cleaning Up The Competition

Signature Series neutralizes acids

Signature Series delivers a high total base number (TBN) for the life of the oil. It neutralizes acidic contaminants, thus keeping them in suspension to maximize engine protection.

You can see why we think Signature Series is the best synthetic oil available. Grab a few quarts for your next oil change and see for yourself.

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AMSOIL Synthetic Motor Oil