A New Level of Motor Oil Technology
- Protects – Ultimate long-life anti-wear protection
- Cleans – Fights sludge and carbon buildup1
- Adapts – Responds to changing conditions
- Performs – Proven beyond the standard2
1Based on Sequence VH and IIIH tests.
2Based on double-length Sequence IIIH test.
Product Overview
Custom-Built to Outperform
AMSOIL Signature Series 100% Synthetic Motor Oil is formulated for drivers who demand the absolute best engine protection. Built with advanced synthetic base oils and a precision-engineered additive system, it is designed to control wear, resist volatility and maintain viscosity under extreme heat, pressure and cold-start conditions. The result is uncompromising film strength, cleaner components and protection that pushes beyond industry standards into a class of its own.
Modern engines place unprecedented stress on motor oil through turbocharging, direct injection, higher temperatures and extended service intervals. Signature Series is engineered to meet those challenges head on, delivering more protection, performance and confidence mile after mile, even during extreme use.
2X BETTER Protection Against Volatility
AMSOIL Signature Series delivers 2X better protection against volatility,3 helping reduce oil consumption, minimize top-offs and keep engines cleaner over time.
3Based on AMSOIL Signature Series 0W-20 100% Synthetic Motor Oil compared to the API SQ limit using the ASTM D5800 Noack volatility test.
Guards Against
Low-speed pre-ignition (LSPI) remains a serious concern in today’s turbocharged, direct-injection engines, where uncontrolled combustion events can damage pistons and other critical components, especially as motor oil ages. AMSOIL Signature Series 100% Synthetic Motor Oil is engineered to help prevent LSPI by maintaining a strong, stable formulation that continues to deliver outstanding performance throughout the drain interval. Even after 25,000 miles of use, Signature Series delivers 4X more piston protection against LSPI4 than the industry standard requires.
4Using AMSOIL Signature Series 5W-30 100% Synthetic Motor Oil following a 25,000-mile service interval in the Sequence IX aged-oil LSPI test.
Preserves Horsepower and Torque
AMSOIL Signature Series 100% Synthetic Motor Oil is built to help engines run stronger, longer5 – helping to protect engines from performance loss throughout their life.
5Using Signature Series 100% Synthetic 5W-30 Motor Oil in a 2025 Ford F-150 Raptor in a 125K-mile accumulation study. Based on comparative start- and end-of-test horsepower and torque.
Proven Cleaning Power
In Sequence IIIH testing, AMSOIL Signature Series delivers 72% more protection against piston deposits than required by industry standards,6 helping ensure cleaner pistons and consistent performance over time.
6Based on AMSOIL Signature Series 5W-30 in the Sequence IIIH Test.
Even after doubling the length of the Sequence IIIH test, Signature Series provided 31% better protection than required,7 demonstrating its ability to maintain cleanliness far beyond industry standards.
7Based on AMSOIL Signature Series 5W-30 in a double-length Sequence IIIH test.
No Sludge, Just Protection
During a 125K-mile accumulation study on a 2025 Ford F-150 Raptor, the engine experienced 0% oil screen plugging.8
8As demonstrated in a 125K-mile accumulation study on a 2025 Ford F-150 Raptor which had 0% plugging.
Ready to buy or need help selecting the right product?
Product information checked: September 2026. Product formulations, specifications, applications, availability and published claims can change.
For the latest official information, consult the AMSOIL Corproate Website.
