Signature Series 5W-20 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.

Product Code ALM

Protects Against Engine Wear and Enhances Performance

Signature Series Synthetic - Best in the industry 5W-20AMSOIL 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.

If you expect the best in your engines this is the industry leader.

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Cam wear kept to a minimum with AMSOIL

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

SEQUENCE IVA ENGINE TEST Lower number = less wear


In this video you will see how the 0W-20 protects in an engine which was designed in 1994 for 5W-30!!

Vehicle Look-up: Match AMSOIL Products to your model

AMSOIL Sioux Falls, the leader in automotive synthetic lubrication, now find locally the entire line from the family owned company which produced the world?s first API-qualified synthetic motor oil in 1972. Trust the extensive experience of AMSOIL and Buy Local!

Buy in the Sioux Falls AMSOIL store at 4610 W. 12th St. or use this Online link to the Amsoil sale page if you are outside of the area.

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 the turbocharger 72 percent better than required2 by the GM dexos1® Gen 2 specification.

Signature Series controlled and minimized performance robbing deposits.

25,000 or 1-year engine protection

Extends Drains: Protection Guaranteed

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.

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.

Amsoil Signature Series keeps Power to the wheels

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.

Lowest NOACK Volatility so less oil consumption

A Test the rest of the industry didn’t even use until AMSOIL set the benchmark.

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.

easier cold starts. See how it pours

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.

Your paying for quality which is measurable in protection AND performance!

Maximum Cleaning Power to Battle Sludge

AMSOIL Signature Series Synthetic Motor Oil has 50 percent more detergents³ to help keep oil passages clean and promote oil circulation. Engine failures due to sludge are often caused by a plugged oil pick-up tube screen – the motor is effectively starved of oil. The Sequence VG Engine Test measures an oil’s ability to prevent sludge. During the test, a Ford 4.6L engine is subjected to sludge-inducing conditions for 216 hours. The industry standard allows for 10 percent blockage before the motor oil fails the test. Signature Series produced a screen virtually free from sludge (see image). Its detergent and dispersant additives are so effective, Signature Series provides 90 percent better protection against sludge.

Check the current Data bulletin for up to date service life and specific industry applications and specifications

Product Data Bulletin

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AMSOIL products are backed by a Limited Liability Warranty. For complete information visit AMSOIL Warranty Information

Additional Regional Ordering & Shipping

If you are outside the area of our Sioux Falls and Sioux Falls stores but in the following states we have a good deal and special shipping rates in the unique Speedee Delivery service areas!! Nebraska, South Dakota, North Dakota, Minnesota, Wisconsin, Iowa, Illinois, and the St. Louis area.  Call 605-274-2580 to get product usually within 1 to 2 days.

What does the “W” on your motor oil’s label really mean? What is the significance of the “0” in 0W-30?

“What?? You’re trying to talk me into a 0W30 over my factory recommended 5W30? Why it’s too thin! And it’s not that cold in my climate!!”

The above is a typical and understandable response to our suggestion to upgrading to AMSOIL’s best. But really our 0W30 is just a better performing oil for ALL applications.

But to better answer the concerns of the customer – the 0W30 isn’t thin. The “W” or winter viscosity is a measure of cold cranking torque. Please read the following:

Winter (“W”) viscosity grades are determined using the Brookfield Cranking viscosity and Brookfield Pumping viscosity tests. The Brookfield Cranking viscosity test evaluates the amount of energy it takes to start an engine at a specified cold temperature; the lower
the winter grade, the lower the temperature at which the Cranking test is performed.

The Brookfield Pumping viscosity test evaluates the amount of energy it takes to pump an oil at a specified cold temperature; the lower the winter grade, the lower the temperature at which the
Pumping test is performed. For example, the 25W viscosity grade has the least rigorous temperature requirements for pumping viscosity (60,000 cP at -15°C) and the 0W grade has the most rigorous pumping viscosity requirement (60,000 cP at -40°C). Brookfield
Viscosity is measured in centipoise (cP).

Cold Cranking index for winter oil ratings

Product Summary

For new cars and high-performance cars requiring 5W-30 or 10W-30 motor oils, the AMSOIL Signature Series 0W-30 is the best overall choice for any situation and all climates. Back in 1999 it was the only oil I used in my Mazda Miata in Texas for 75,000 miles which ran in several road race weekends, redline conditions on the road, hard rush hour traffic in the Texas heat and more. It’s not just a cold weather product but AMSOIL’s ultimate performer containing the latest of additive technology available. It’s always my #1 suggestion in all new vehicles requiring a multi-weight “30” oil. For 5W-20 we also have the 0W-20 option. These products will also provide the best protection in turbo engines as well.

Call me at 800-579-0580 any time for the best price or click on the links to the store.

Thank you for visiting The Synthetic Warehouse and Oil Ordering!

Customer Comments:

Buy it again, over and over and over for more than a decade

Comments about Signature Series 0W-30 Synthetic Motor Oil

Is there something proven better to use? I researched before first purchasing this oil for nearly 13 years in the same 2002 Ford F150. Use the Amsoil filter to trap more contaminants that occur over time as well. The vehicle has less than 29Kmi on the odometer. My most recent oil change had less than 850 miles over a 13 month period. It’s perfect for preserving and extending the life of any engine and with my truck this oil is an absolute.

Better gas mileage and longer time on oil changes

Comments about Signature Series 0W-20 Synthetic Motor Oil

The best motor oil you can by hands down. Check out the oil analysis on-line. I went 19k miles on my Prius and oil analysis said that I could go on up to 22k without any issues. This was and independent oil lab.

By Luis 1/4/2017

from undisclosed

I use it on my ford vehicles. The product and lab reports on it speak for themselves. This is a must product if your vehicle requires it.


Amazing synthetic oil.
By David 12/31/2016

from undisclosed

I swear by this oil. Simply the best fully synthetic oil out there. I got 220000 miles on my Altima and still has great fuel mileage and power.