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Amsoil 5W-20 Signature Series

Last updated: February 22nd, 2026
Amsoil Signature Series 5W-20 100% Synthetic Motor Oil (ALM)

Amsoil 100% synthetic motor oils are specifically designed to save you money and increase performance. With extended drain intervals of 25,000 miles or more, Amsoil 100% synthetic motor oils will improve your gas mileage, increase power and reduce engine wear. Give your automobile the lubrication it needs by switching to Amsoil 100% synthetic lubricants today.

Features And Benefits of Amsoil 5W-20

  • 25,000 mile or one year drain intervals
  • Outstanding protection for turbo and direct injection
  • Industry leading cold weather properties
  • Top of the line product for maximum wear protection

Available Packaging for ALM

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Technical Info PDF

This product will typically ship within 24 hours from one of Amsoils 14 distribution centers in North America. This means that the product will ship to you from the closest possible location and most orders end up arriving in two to three days or less! Expedited shipping options are available as well.

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Performance Tests and Comparisons
100,000 Mile Wear Protection Test
Amsoil 5W-20 Provides world class protection. Amsoil was compared head to head with a leading competitor in a 100,000 mile test and showed superior bearing and wear protection. When measuring average cam wear in the sequence IVA test, Amsoil showed 75% more protection against loss due to engine horsepower and wear!
amsoil wear performance test
View The Wear Protection Test
Low Speed Pre Ignition (LSPI) Prevention Test
Over the course of five tests, Amsoil had zero LSPI events. Low speed pre ignition occurs when there is a premature ignition of the fuel during the combustion cycle. This can result in poor performance, knocking and engine damage.

The image below shows damage that occurred to a piston during the failure of a competitors oil in the LSPI test.

amsoil LSPI test
View The LSPI test
Acid Neutralization Test
Amsoil offers superior acid neutralization qualities when compared to the competition. A powerful detergent additive package gives amsoil 30% more acid protection than Mobil 1 and Royal Purple. The image below shows the total base number of Amsoil after the test, compared to other leading competitors.
amsoil acid neutralization test
View The Acid Neutralization test
Turbo Protection Test
Amsoil Signature Series exceeds GM Dexos1 Gen2 turbo charger protection requirements by over 70%. Amsoil protects against sludge, deposits and other performance robbing deposits on the turbo shaft. Additionally Amsoil showed excellent heat control properties.
amsoil turbo test
View The Turbo Protection test
Oil Volatility Test
Amsoil Signature Series motor oils fight volatility better than both Royal Purple and Mobile 1. Volatility occurs when an engine oil loses weight due to evaporation at normal to high operating temperatures. Amsoil loses the least amount of weight compared to the leading competitors.

The graph below shows that Amsoil only had a 6% loss of volatility during the test. Well ahead of the competition and well below the industry standard. The lower the loss, the better!

amsoil volatility test
View The Volatility test
Applications
Amsoil Signature Series 5W-20 is usable in engines with the following specifications:
  • API SP (Resource Conserving)
  • SN Plus
  • SN GM dexos1 Gen 2 (supersedes 6094M)
  • ACEA A1/B1
  • Ford WSS-M2C945-B1
  • Ford WSS-M2C945-A
  • Ford WSS-M2C930-A
  • Chrysler MS-6395
  • ILSAC GF-6A
  • ILSAC GF-5
  • ILSAC GF-4
Amsoil 5W-20 Frequently Asked Questions
Amsoil 5W-20 uses high-quality synthetic base oils and a balanced additive system to deliver strong wear protection, clean operation, and stable viscosity. The Signature Series formulation enhances these benefits with improved oxidation resistance and long-term performance.
Many newer engines are engineered around low-viscosity lubricants to reduce friction and improve efficiency. A 5W-20 grade flows quickly at startup and maintains the proper film strength at operating temperature, helping support fuel economy and smooth operation in engines designed for this viscosity.
This formulation resists breakdown under heat, controls deposits, and maintains its viscosity better than many conventional 5W-20 oils. Amsoil’s synthetic chemistry helps protect critical components, reduce wear, and support longer service intervals when used according to recommended guidelines.
Yes. This low-viscosity synthetic oil is engineered to reduce internal drag and flow efficiently through tight engine tolerances. By minimizing friction and maintaining stable viscosity, it can help support improved fuel economy in vehicles designed for 5W-20.
Signature Series 5W-20 is built for long-drain performance thanks to its oxidation resistance and robust additive package. In mechanically sound engines, it can maintain protection over extended intervals when used according to Amsoil’s service recommendations.
The synthetic formulation flows quickly in cold weather to reduce startup wear and reaches vital components faster than many conventional oils. At high temperatures, it resists thinning and oxidation, helping maintain a protective film under heavy loads or extended operation.
Yes. Its detergent and dispersant system is designed to control sludge, varnish, and deposits that can form in modern engines. By resisting oxidation and keeping contaminants suspended, Amsoil’s 5W-20 helps maintain cleaner internals and consistent performance.
It is. This synthetic 5W-20 is formulated to handle the heat and rapid oil flow demands common in turbocharged applications. Its strong film strength and resistance to turbo-related deposits help protect bearings and other high-speed components.
Yes. Signature Series 5W-20 provides excellent protection for newer engines while also offering stable lubrication for higher-mileage vehicles. Its cleaning and anti-wear properties support long-term durability without aggressively dislodging deposits.
It is compatible with other synthetic and conventional oils, though mixing reduces its performance advantages. Additional aftermarket additives are not recommended, as the Signature Series 5W-20 formulation already includes a complete, balanced additive package.

The Performance Oil Company

An Authorized Amsoil Dealer
Allenton, Wisconsin 53002
(262)-388-3411