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AMSOIL Signature Series 0W-40 100% Synthetic Motor Oil

Product code : AZFQT-EA

A New Level of Motor Oil Technology

  • 75% more engine protection against horsepower loss and wear.1
  • 50% more cleaning power vs. AMSOIL OE Motor Oil
  • Protects turbochargers 72% better than required2 by the GM dexos1 Gen 2 specification.
  • 28% more acid-neutralizing power than Mobil 1.3
  • Trusted by professional engine builders
  • Guaranteed protection for up to 25,000 miles or 1 year

1Based on independent testing of AMSOIL Signature Series 0W-20 using the ASTM D6891 standard test.
2Based on independent testing of AMSOIL Signature Series 5W-30 in the GM turbo coking test.
3Based upon independent testing of Mobil 1 Annual Protection Full Synthetic 5W-30 and AMSOIL Signature Series 5W-30 in ASTM D2896. Oils purchased in July 2020.

AMSOIL Signature Series 0W-40 100% Synthetic Motor Oil



Engineered for enthusiasts seeking maximum protection and performance. Precision-formulated with cutting-edge technology and a longstanding devotion to making the world’s best motor oil. The result: engine protection that blows the doors off the highest industry standards.

See the Product Data Bulletin for full details.

Fights Engine Wear

  • 75 percent more engine protection against horsepower loss and wear1 than required by the industry standard, extending the life of vital components like pistons and cams.
  • Develops a strong fluid film that keeps metal surfaces separated.
  • Robust anti-wear additives further reduce wear in metal-to-metal contact regions for maximum engine life.

1Based on independent testing of AMSOIL Signature Series 0W-20, in ASTM D6891 as required by the API SN specification.


Signature Series Improves Startup Protection

AMSOIL provides better cold cranking viscosity, helping improve wear protection for engine components at startup.PP

ASTM D5293 cold Crank (Lower = Better)

ASTM D5293 Cold Crank (Lower=Better)

  AMSOIL Signature Series(5W-30) Royal Purple High Performance (5W-30) Lucas (5W-30) Driven LS30 (5W-30) Red Line High Performance (5W-30) Royal Purple HPS (5W-30)
Cranking Viscosity (㎫ ●s) 3800 4500 5000 5750 6100 6100

PPBased on independent third-party testing in the industry-standard ASTM D5293 Cold Crank Simulator test as required by SAE J300.
*Trademark 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.


Signature Series Fights Wear

75% more engine protection against horsepower loss and wear.A

Sequence IVA Engine Test - Lower Number = Less Wear

Sequence IVA Engine Test - Lower Number = Less Wear

  Industry Standard AMSOIL Signature Series 0W-20 Synthetic Motor Oil
Average Cam Wear 90 20.28

ABased on independent testing of AMSOIL Signature Series 0W-20, in ASTM D6891 as required by the API SN specification.


Signature Series Delivers Powerful Protection

AMSOIL delivers powerful protection. How good is it? An independent lab compared AMSOIL synthetic motor oil head-to-head against a leading competitor in a 100,000-mile test.P AMSOIL provided far superior wear protection and kept bearings looking like new.

Test results from AMSOIL against leading competitor in 100,000-mile test.

PTesting conducted in an independent lab using AMSOIL Signature Series 5W-30 Synthetic Motor Oil and a leading synthetic-blend 5W-30 motor oil in Ford F-150 trucks with 3.5L twin-turbo engines.


Signature Series Protects Against LSPI

AMSOIL Synthetic Motor Oils achieved 100% protection against LSPI.B

Piston damage due to an LSPI event observed during the testing of a competitor’s motor oil.

Example of piston damage due to an LSPI event observed during the testing of a competitor’s motor oil. The red arrows indicate sections of the ring land that have broken away from the piston.

BBased on zero LSPI events in five consecutive tests of AMSOIL Signature Series, XL and OE 5W-30 Motor Oil in the LSPI engine test required by the GM dexos1 Gen 2 specification.


Signature Series Resists Viscosity Increase

Signature Series is barely challenged by the industry-standard testing, demonstrating only a 0.1% viscosity increase. Even when the test length is doubled, AMSOIL delivered twice the viscosity control required by the standard.GG

Sequence IIIH Engine Test - Lower number = better viscosity control

Sequence IIIH Engine Test - Lower number = better viscosity control

  Industry Standard AMSOIL 1X AMSOIL 2X
Viscosity Increase % 100% 0.1% 49.6%

GGBased on independent testing of AMSOIL Signature Series 5W-30 in the Sequence IIIH Engine Test (ASTM D8111), required by the ILSAC GF-6 and API SP specifications.


Signature Series Helps Keep Engines Cleaner

  • Fortified with a heavy treatment of detergent additives, delivering 28% more acid-neutralizing power than Mobil 1* and helping engines stay cleaner, longer.LL
  • 50% more detergentsD to help keep oil passages clean and promote oil circulation.
  • Controls heat and minimizes performance-robbing deposits.
  • Superior thermal durability that resists breakdown and keeps pistons clean.
  • Provides 90% better protection against sludge.DD

Oil pick-up tube screen showing it's virtually free of sludge.

The oil pick-up tube screen is virtually free of sludge.

LLBased upon independent testing of Mobil 1 Annual Protection Full Synthetic 5W-30 and AMSOIL Signature Series 5W-30 in ASTM D2896. Oils purchased July 2020.
Dvs. AMSOIL OE Motor Oil
DDBased on independent testing of AMSOIL Signature Series 5W-30 in the ASTM D6593 engine test for oil screen plugging as required by the API SN specification.


Signature Series Guards Turbos

Protects turbochargers 72% better than requiredC by the GM dexos1* Gen 2 specification.

Part from turbocharger.

CBased on independent testing of AMSOIL Signature Series 5W-30 in the GM turbo coking test.


Keeps Pistons Cleaner

Even after doubling the length of the industry-standard test, AMSOIL delivered 40% cleaner pistons than required by the standard.FF

Piston 40% cleaner from using AMSOIL.

FFBased on independent testing of AMSOIL Signature Series 5W-30 in the Sequence IIIH Engine Test (ASTM D8111), required by the ILSAC GF-6 and API SP specifications.

 

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AMSOIL Signature Series 0W-40 100% Synthetic Motor Oil

Data Bulletin

Warranty

SDS



AMSOIL Signature Series 0W-40 100% Synthetic Motor Oil

  • 5 star rating
    Signature Top of the line
    By  KELLY,  a  Verified Buyer  on  June 17, 2025
    Fast delivery service. Top of the line oil for My Hemi. Have used Amsoil in every engine I have since 2002 from Harley's to lawnmowers to Hemi's, also so far I've NEVER had the Hemi tick and I credit it to Amsoil...
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    Best Motor Oil in the market
    By  EDWARD,  a  Verified Buyer  from  Los Angeles  on  June 17, 2025
    I never thought in my life how much a quality motor oil can make a huge difference to my car. I have used Mobil 1, Castrol, Supertech, Kirkland, which all of them did the minimal job its supposed to do, keep my car operating and no sludge. However, the moment I used Amsoil Signature Series, my car has not only been getting benefits of protection but my engine has been revitalized where it feels lile it has no friction. My mpg has drastically improved by 10+ mpg. I have now learned the difference between 100% synthetic and full synthetic. Despite the upfront cost, it is actually a free motor oil compared to buying any other brand. I have saved more money through gas mileage that it makes up more than enough for my car. This oil exemplifies the saying of being cheap is more expensive. Better to buy the best oil and save more in the long run than buying a cheap oil that will cost you more down the line through gas mileage and possibly engine wear.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    In Honda direct injection,
    By  JOHN,  a  Verified Buyer  from  Western Fredonia  on  June 17, 2025
    My two Honda vehicles love this oil! Runs smooth, and engines seem more efficient as my fuel mpg is now (25.0 mpg). 2024 Honda Ridgeline. My wife’s 2022 Honda CRV turbo runs incredibly smooth, and is getting 36.0 mpg. This is the only oil going in our engines.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    Signature series
    By  SPENCER,  a  Verified Buyer  on  June 17, 2025
    A friend recommended this for my Toyota tundra. He said it made his engine quieter. I changed to this oil and immediately on start up my engine was noticeably quieter and better protection.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    Amsoil Signature Series 0W-20 Motor oil
    By  JAMES,  a  Verified Buyer  from  Fallon, Nevada  on  June 16, 2025
    Been using Amsoil Signature Series 0W-20 for Years. When I bought my 2020 Toyota Tacoma new , been using Amsoil Signature every oil change once a year. The weather here in Nevada, in summer it Hot! Hot! Hot! In winter it Cold! Cold! Cold! This oil is outstanding!!!
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    Best oil
    By  Jim,  a  Verified Buyer  from  Pa  on  June 15, 2025
    Run amsoil in everything, 5w-30 goes in a 97 Avalon with 375k miles. Amsoil increased mpg avg by almost 3, this was switching from mobile 1.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    2019 Honda Accord
    By  CAMILO,  a  Verified Buyer  from  Miami  on  June 15, 2025
    Currently loving the oil, but have yet to fix oil conception in a GDI engine. Oil dilution is still a part of my life, but I have noticed some improvement. I do wanna try the restore and protect oil from Vavoline, see if it can help, and then switch back to Amsoil.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    Outstanding oil
    By  SCOTT,  a  Verified Buyer  from  Minnesota  on  June 15, 2025
    0W-30 Signature oil really protects, cleans, resists gumming, foaming. My SUV starts quickly even in the most severe cold temperatures yet holds full proper oil pressure at extreme heat. Top quality and MORE than worth every penny per ounce!
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    Oil change
    By  CLINT,  a  Verified Buyer  from  Crestview   on  June 14, 2025
    I would recommend this oil for everyone, this is the only oil I put in either of my vehicles.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    Amsoil
    By  PERRY,  a  Verified Buyer  from  B.C  on  June 14, 2025
    The only product I use. Since 1994
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?