AMSOIL Signature Series 0W-20 100% Synthetic Motor Oil
Custom-Built to Outperform
ASM1G-CA
ASM1G
ASM55
ASMQT-CA
ASMQT
Product highlights
1Based on Sequence VH and IIIH tests.
2Based on double-length Sequence IIIH test.
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.
See the Product Data Bulletin for full details.
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.
Customer Reviews
5.0 out of 5 from 7018 reviews
Great Oil
I have been using the oil in my Semi Truck and my F350 pickup I decided to use it in my Wife's car. The Oil is a great product and I'm sure it will prolong the life of the engine in my wife's vehicle.
Truck
Best oil out there even the Toyota mechanic said great choice
I trust Amsoil
I plan to continue to partner with Amsoil. I trust the safety of my family on the roadway with their various products. Deliveries are always accurate and the products are quality.
1500 riding quiet.
New to this product but the Silverado is running quiet at 80000. I normally change the oil at 5000 but will run to 7500.
Using since 2018
This is the only oil I’ve put in my 2018 Chevy Silverado 1500 since I purchased it in 2018. I’m convinced this has kept my truck alive with 146,000 miles on it.
Great product
Great product I live in the middle of the Arizona desert where its hot 9 1/2 months out of the year So i need the best of the best oil to protect my vehicles I only wish you could find this product at a local auto part store
Great product!
I have been using Amsoil products for my autos and motorcycles for over 20 years. I have never had any problems or issues. Great stuff!
great product for my turbo charged engine
I have been using 0W-30 Amsoil in my Hyundai Santa Cruz for 2 1/2 years. Doing my research on turbo chargers, Amsoil is rated number one. Love the product.
The best oil ever
I’ve been using Amsoil for nearly 20 years, simply had no rival
Great stuff!
This has always been the go to for our cars.
