Signature Series 0W-20 100% Synthetic Motor Oil

UPGRADED AMSOIL signature series 0W-20 Synthetic

Engineered for enthusiasts seeking maximum protection and performance. If you want to keep that vehicle for the long term and you may or may not push it hard, you need Signature Series!

SKU: ASM Category:

Amazing Protection – Signature Series 0W-20

If you need a 0W-20 you need one which stays it’s viscosity. You need a synthetic that has been tested to prevent wear in engines designed in the 1990’s for 5W-30! Our 0W-20 works that well.

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.

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amsoil 0W-20 signature series

Protects Against Engine Wear

AMSOIL Signature Series Synthetic Motor Oil 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. The Sequence IVA Engine Test, which must be passed to meet the industry-standard API SN specification, simulates extended periods of stop-and-go driving. For 100 hours, the test engine cycles between 50 minutes of idling and 10 minutes of elevated rpm – conditions that encourage engine wear. The camshaft is then measured for wear in 84 locations and an average score is determined. We used Signature Series 0W-20, the lightest viscosity in the line, to further increase the severity of the test. AMSOIL Signature Series Synthetic Motor Oil provided 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. Based on independent testing of AMSOIL Signature Series 0W-20, in ASTM D6891 as required by the API SN specification.


royal Purple never tests as good as amsoil

cam wear prevented with Amsoil Signature Series

After rigorous third-party testing, the cam lobes show little-to-no wear.


Lower number = less wear


Dealers Note:

Ultimate AMSOIL Dealer Busines - Office, retail sales outlet and AMSOIL VanI run this in my Ford Ecoboost 1.6 Ford Transit Van. As I add miles, the mileage seems to get better all the time. As it’s a turbocharged GDI motor which is exactly what this oil was designed for. Designed to run hot! AMSOIL henceforth is the only choice! Only their unique base stock can prevent the effects of oil deposits from building up within the intake system over a long period of time. None the less LSPI as newer versions of GDI engines are produced with more advanced timing.  I haul 1200 to 1400 pounds every other week 280 miles and I am now seeing 24 to 26 MPG on the interstate cruising at 65 to 70 (depending on weather conditions) and over 30 miles per gallon on empty loads. Testing shows all other premium products will leave 20% or more deposits in this engine. Thus AMSOIL Signature Series is the only choice! (5W-30 is required in the larger SIX Cyl. engines and 5W-20 or 0W-20 is the recommendation for select four cylinder ones.)

Protects Pistons from Low-Speed Pre-Ignition

We armed Signature Series with an advanced detergent system that protects against harmful deposits and low-speed pre-ignition (LSPI). Most new engines feature gasoline direct injection (GDI), often combined with a turbocharger to boost power and improve fuel economy. These new technologies, when combined with a poorly formulated motor oil, promote LSPI and threaten engine operation. LSPI is the spontaneous ignition of the fuel/air mixture prior to spark-triggered ignition. It occurs in today’s advanced engines and is much more destructive than typical pre-ignition.Original equipment manufacturers (OEMs) like GM* have addressed the issue by designing tests to determine a motor oil’s ability to prevent LSPI. The GM test allows up to five LSPI events to receive a passing score. Signature Series Synthetic Motor Oil provided 100 percent protection against LSPI1 – zero occurrences were recorded.

Protects Turbochargers

Our unique synthetic formulation is inherently stable to resist oxidation and neutralize acids. Signature Series Motor Oil provides outstanding protection against deposits common to high-temperature engine environments. The tremendous heat and stress turbos create can cause some oils to break down and form harmful bearing deposits through a process known as turbo coking. Over time, turbos can suffer reduced performance or fail altogether.We challenged Signature Series to the GM Turbo Coking Test, which consists of 2000 cycles of extreme heat soaks. An oil must limit the temperature change within the turbocharger to 13 percent or less to pass the test. Signature Series limited the temperature increase to only 3.6 percent, protecting theturbocharger 72 percent better than required2 by the GM dexos1® Gen 2 specification.

LSPI Prevention - see what competitors oil will do

Max protection available in a motor oil

AMSOIL, the leader in automotive synthetic lubrication, produced the world’s first API-qualified synthetic motor oil in 1972. Trust the extensive experience of AMSOIL, the First in Synthetics®, to do the best job protecting your engine.

“If you need a 0W-20 (or 20 weight motor oil) this is the one you want to use. Keeps it’s viscosity under all loads and delivers year round maximum efficiency. This was designed to replace any 5W-20 viscosity for a better performing all around product.”

The Signature Series is the best oil available and features the true 100% synthetic formula.

Extends Drains: Protection Guaranteed

“Oh I don’t care how many miles it says you can go – I’ll still change at the factory recommendations” – Actually we agree. The extended drain information is a way to show just how tough these lubricants are. They are showing you the available protection compared to the rest. Problems, added loads, unexpected failures (lost coolant, etc) dirty valves, will have less implications when using the Signature Series.

AMSOIL Signature Series Synthetic Motor Oil provides reserve protection, allowing you to go longer between oil changes if you choose – up to 25,000 miles, 700 hours of operation or one year, whichever comes first*. Our unique synthetic formulation and long-drain additive system are inherently stable to resist oxidation and neutralize acids over longer periods. Signature Series is designed to deliver outstanding engine protection, cleanliness and performance over extended drain intervals – guaranteed. It provides peace of mind so you can fit oil changes into your schedule.

bearing wear protection

1 Based on independent testing of AMSOIL Signature Series 5w-30 motor oil, in the LSPI engine test as required for the GM dexos 1® Gen 2 specification.
2 Based on independent testing of AMSOIL Signature Series 5W-30 in the GM turbo coking test.
3 vs. AMSOIL OE Motor Oil
4 Based 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.
* All trademarked 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. All products advertised here are developed by AMSOIL for use in the applications shown.

Preserves Horsepower

The extreme durability of Signature Series Motor Oil ensures your engine runs stronger, for longer. We installed Signature Series 5W-30 Synthetic Motor Oil in a Ford* F-150 with a new 3.5L Ecoboost engine to test its ability to protect turbocharged direct-injection (TDGI) engines from torque and horsepower loss during extended drain intervals up to 25,000 miles. Power sweeps were done at the beginning and end of the test to evaluate horsepower and torque retention. As the graph shows, Signature Series helped maintain engine performance throughout the 100,000 mile test.

Less horsepower loss measured with AMSOIL products

Limits Oil Consumption

Signature Series has a uniform molecular structure that limits evaporation and keeps it where it’s needed most – protecting your engine. Volatility (burn-off) occurs when oil gets hot, causing lighter molecules to burn off or evaporate. This leads to oil thickening, additive imbalance, higher emissions and oil consumption. The NOACK Volatility test is the industry standard for evaluating motor oil high temperature evaporation. It measures the percentage of burn-off after a motor oil is placed under constant airflow at 482ºF for 1 hour. A lower number indicates a better resistance to evaporation. Signature Series falls far below the API limit for volatility, reducing the need for frequent oil top-offs and limiting vehicle emissions.

volitility scale to other synthetics

Easier Cold-Starts

Signature Series Synthetic Motor Oil does not contain paraffins (wax) and stays fluid in temperatures of -58ºF and lower. Extreme cold causes other motor oils to thicken, starving vital moving parts of lubrication, accelerating wear and even preventing vehicles from starting. Signature Series provides 66 percent better cold-temperature performance for easier starting, better fuel economy, improved oil flow (as seen below) and reduced wear.

could pour point of amsoil

AMSOIL synthetic pours easier at start-up

Maintains Protective Viscosity

We formulated Signature Series with superior thermal durability that resists breakdown better than conventional and synthetic motor oils. The Sequence IIIH Test uses the Chrysler 3.6L Pentastar engine to evaluate a motor oil’s ability to resist the damaging effects of heat. The test is conducted with oil temperatures of 304ºF, 100ºF hotter than normal operation, to accelerate oil thickening and deposits. Despite the extreme conditions, Signature Series kept pistons clean and held thickening to only 6 percent, a minimal amount compared to the proposed specification limit of 150 percent.1 This stay-in-grade performance helps maintain maximum power and fuel economy while also ensuring advanced technologies like variable valve timing (VVT) operate as designed throughout the entire drain interval.

viscosity increase and retention

Not only do pistons stay clean, the oil can clean dirty ones.

1 Based on proposed ILSAC GF-5 Plus specification.
* All trademarked 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. All products advertised here are developed by AMSOIL for use in the applications shown.



Manufacturer APPLICATIONS for Amsoil 0W-20 Signature

AMSOIL Signature Series Synthetic Motor Oil is excellent for use in all types of gasoline-fueled vehicles. It is recommended for all domestic and foreign vehicles requiring any of the listed performance specifications:

0W-20 (ASM): API SP (Resource Conserving), SN PLUS, SN…; GM dexos1* Gen 3
(supersedes dexos1 Gen 2 and 6094M); ACEA A1/B1;
Ford WSS-M2C947-B1, WSSM2C947-A, WSS-M2C962-A1; Chrysler MS-6395; ILSAC GF-6A, GF-5, GF-4


AMSOIL 0W-20 Signature Series Synthetic Motor Oil is compatible with other conventional and synthetic motor oils. Mixing AMSOIL motor oils with other oils, however, will shorten the oil’s life expectancy and reduce its performance benefits. AMSOIL does not support extended drain intervals where oils have been mixed.

Aftermarket oil additives are not recommended for use with AMSOIL synthetic motor oils.


Normal Service – Up to 25,000 miles, 700 hours of operation or
one year, whichever comes first, in personal vehicles not operating
under severe service.
Severe Service – Up to 15,000 miles, 700 hours of operation
or one year, whichever comes first. Severe service conditions
include commercial or fleet vehicles; excessive idling; or frequent
towing, hauling, plowing or driving in dusty conditions.

  •  Modified engines (non-stock), racing vehicles and vehicles
    using alternative fuels (E85, CNG, propane, etc.) are excluded
    from extended drain interval recommendations.
  •  Change at the vehicle manufacturer’s recommended drain
    interval outside U.S. and Canada.
  • AMSOIL Ea® Full-Flow Oil Filters are designed for extended drain
    intervals. Do not exceed 12,000 miles or one year with other
    brand filters unless longer intervals are recommended by the
    vehicle manufacturer. Always change filter when changing oil.
  • Check oil regularly to maintain proper fill levels.

AMSOIL Ea Full-Flow Oil Filters stop smaller particles, flow more oil and last longer than regular filters. For best performance, use AMSOIL Ea Full-Flow Oil Filters.

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See Data Bulletin for more details

0W-20 Product Reviews


Decade’s later still a fantastic product

By  JAMES,  a  Verified Buyer  from  New Brunswick Canada  on  December 10, 2023
I have used this product and many others from AMSOIL and it’s performance has been second to none. Yes i have seen increased fuel mileage, and I know this means less friction, easier cold starts and better hot weather performance. Yes you really can realize a difference of you switch from your current oil and Use Signature Series Synthetics

Simply The Best Motor Oil

By  TONY,  a  Verified Buyer  on  December 10, 2023
Received my shipment fast. My Ford F250 6.2L runs better and smoother than it did with other Synthetic oils. I highly recommend this oil for anyone who wants their automobile engine to last longer.

Newer Honda’s/Toyota/Lexus best oil

By  RUSSELL,  a  Verified Buyer  from  Glasgow Kentucky   on  April 20, 2023
When buying new SUV or cars costing $50 to $90K the best oil is valuable insurance for long life of engines. I said the life of the engine is the life of the vehicle

Amsoil Signature Series 0w-20 full synthetic motor oil

By  James,  a  Verified Buyer  from  WA  on  April 23, 2023
Use this Amsoil in my Chevy Equinox for years now and am sold for ever! I even noticed a slight improvement in the gas mileage,plus it last like it should and seems to stay cleaner with long intervals!

Great oil!!

By  CLIFF,  a  Verified Buyer  from  Massachusetts   on  April 20, 2023
I use this oil in my wife’s Honda Pilot and at 5,000 miles it’s still a nice golden amber brown. It makes her car run so quiet you can’t even hear it running going down the highway.

Best oil on the market!

By  JEFF,  a  Verified Buyer  from  Fort Erie Ontario Canada  on  April 19, 2023
Our suv runs super smooth with this oil!

2002 Toyota Avalon LOVES It

By  GryGuy,  a  Verified Buyer  from  Kentucky  on  April 17, 2023
Old 2002 Toyota Avalon runs smooth as can be with this oil. Intervals are safe at 13,000-15,000 miles. Mechanic always compliments us on the old and new oil/filters. Thanks AMSOIL

Less Oil Changes

By  MARK,  a  Verified Buyer  from  IA  on  April 15, 2023
Oil lasts more miles, therefore less time spent changing it.

Incredible result!!!

By  NOEL,  a  Verified Buyer  on  April 15, 2023
I can’t believe this oil would give significant change in the performance of my Honda Accord 1991. My car runs so smooth and quiet. It also gave me extra miles per gallon. Exceptional product!!!

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