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.
Signature Series 5W-20 100% Synthetic Motor Oil
Dealer’s Note:
The only brand designed to prevent LSPI effects 100%. 5W-20 (And 0W-20 which is technically the same thing) motor oils are the trend and you can’t afford to use one that will change viscosity prematurely or evaporate. From 2018 to 2025 the main concern by manufactures is the oil. It has to withstand issues which previously did not exist. AMSOIL stands alone due to the company’s determination to only use the best base oils and additives available. There are no stock holders to reduce the quality of materials to make profit demands. Just look at the reviews. But aside from the companies philosophy and determination, I say from my own experience, “The only test you need is the seat of the pants!” – because it was the performance which pushed me to become a dealer. I was instantly impressed. Nothing comes close to the 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.
After rigorous third-party testing, the cam lobes show little-to-no wear.
AMSOIL, the leader in automotive synthetic lubrication, produced the worlds 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.
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.
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.
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.
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.
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.
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.
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.
Applications
5W-20 (ALM): API SN (Resource Conserving), SM…; GM dexos1Gen 2 (supersedes
6094M); ACEA A1/B1; Ford WSS-M2C945-A, WSS-M2C930-A; Chrysler MS-6395; ILSAC
GF-5, GF-4… Fortified with detergents that exceed the dexos1 Gen 2 sulfated ash
specification.
SERVICE LIFE
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.
Buy & Pricing
AMSOIL PRODUCT WARRANTY
AMSOIL products are backed by a Limited Liability Warranty. For complete information visit www.amsoil.com/warranty.aspx.
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