Why Buy Signature Series?

AMSOIL Signature Series 100% Synthetic Motor Oil is engineered for enthusiasts seeking maximum protection and performance. It’s 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.

How good is it? Signature Series is not only the best motor oil we have ever made, it’s better than any competing oil that we have tested. Advanced engine technology and rigorous demands placed on modern vehicles can challenge motor oil, eventually leading to decreased engine performance and life. Signature Series delivers the ultimate protection against extremes like high-performance driving, off-roading, towing and extended idling. Its boosted protection also lets you drive further between oil changes.

Some may claim that Signature Series Motor Oil is overbuilt. Perfect. It’s not for everyone. It’s for those who want the absolute best engine protection. Is it the right motor oil for you?

Do you want to prevent horsepower loss and wear?

Dirty or worn components work poorly and don’t last. They cause system failures in engines that dramatically increase maintenance costs and reduce vehicle life. Clean and protected engine components, on the other hand, require less maintenance, produce more horsepower, are more fuel efficient and help increase engine life.

Signature Series 100% Synthetic Motor Oil develops a strong fluid film that keeps metal surfaces separated. Its advanced 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 API SN PLUS 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.

AMSOIL Signature Series 100% Synthetic Motor Oil provided 75% more engine protection against horsepower loss and wear^A than required by the industry standard, extending the life of vital components like pistons and cams.

In another test, an independent third-party lab compared AMSOIL synthetic motor oil head-to-head against a leading competitor in a 100,000-mile test. AMSOIL Signature Series provided far superior wear protection compared to the competition, keeping bearings looking like new after the 100,000-mile test.^P

Do you drive in hot temperatures?

Engine sludge is the result of a series of chemical reactions that cause oil to degrade. These reactions are driven by exposure to oxygen and elevated temperatures. The higher the temperature, the more rapid the rate of degradation. In fact, every 18°F (10°C) increase in operating temperature doubles the rate of oxidation.

The byproducts of this reaction form highly reactive compounds that further degrade the lubricant. These byproducts react with other contaminants, forming organic acids and high-molecular-weight polymeric products. These products further react, forming the insoluble product known as sludge. What begins as a thin film of lacquer or varnish builds up on hot or cold metal surfaces and bakes into an expensive mess.

We engineer Signature Series with superior thermal durability that resists breakdown and keeps pistons clean. The Sequence IIIH Test uses the Chrysler* 3.6L Pentastar* engine to evaluate a motor oil’s ability to resist heat and keep pistons clean. The 90-hour test is conducted with oil temperatures of 304°F (151°C), much hotter than normal operation, to accelerate oil thickening and deposits.

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

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

Do you have long commutes?

Do you rack up the miles on your vehicle? Signature Series 100% Synthetic Motor Oil provides reserve protection, allowing you to go longer between oil changes if you choose – up to 25,000 miles (40,200 km) or one year, whichever comes first. Our proprietary 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.

Signature Series keeps engines cleaner, longer. It is fortified with a heavy treatment of detergent additives, delivering 28% more acid-neutralizing power^LL than Mobil 1,* helping engines stay cleaner, longer.

Does your vehicle have a turbocharger?

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 2,000 cycles of extreme heat soaks. An oil must limit the temperature change within the turbocharger to 13% or less to pass the test. Signature Series Motor Oil provides 72% better turbocharger protection than required by the GM dexos1 Gen 2 specification.^C

Do you want better startup protection?

Most engine wear occurs at startup. That’s primarily because oils thicken as the temperature drops. Cold oil doesn’t flow as fast and, in some cases, may not be able to flow through tiny oil passages at all. When that happens, engine components are forced to operate without lubrication until the engine warms up the oil enough for it to flow, greatly accelerating wear. For those reasons, cold-flow capability is a critical measure of motor oil performance.

We hired an independent third-party lab to put Signature Series in head-to-head testing against other motor oil brands. Signature Series provided better cold-flow performance than all the other motor oils tested, providing up to 38% better cold cranking viscosity than Royal Purple. The test definitively proved that AMSOIL provides better cold cranking viscosity, helping improve wear protection for engine components at startup.^PP

Do you want to guard against LSPI?

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. A properly formulated motor oil is critical for protecting your engine.

Signature Series is armed with an advanced detergent system that protects against harmful deposits and low speed pre-ignition (LSPI). Engines equipped with gasoline direct injection (GDI) combined and a turbocharger provide boosted power and fuel economy. But when these technologies are combined with poorly formulated motor oil, LSPI can become a real threat for the engine.

Vehicle manufacturers like GM* have addressed the issue by designing tests to determine a motor oil’s ability to prevent LSPI. AMSOIL Signature Series 100% Synthetic Motor Oil achived 100% protection against LSPI^B in the engine test required by the GM dexos1* Gen 2 specification – zero occurrences were recorded throughout five consecutive tests.

Do you trust professional performance engineers?

AMSOIL and Lingenfelter Performance Engineering (LPE) are strategic partners with a mission to push the bounds of vehicle performance. AMSOIL products are the “Official Lubricants of LPE.”

“The choice for us was performance based,” said Mark Rapson, COO/VP of Operations for Lingenfelter Performance Engineering. “We are continuously pushing the performance envelope of today’s late-model platforms. 700+ hp, high-rpm, naturally aspirated engines and 1,000+ hp supercharged and turbocharged street cars are now very common. The technology that makes this possible – computerization, DI, hotter and leaner combustion cycles – all bring special demands to engine components, including motor oil.

“During our R&D work, we began to experiment with and evaluate top oil brands to understand performance differences in given applications,” continued Rapson. “We were surprised at the differing results and found that AMSOIL gave the best performance in our application. This led us to contact AMSOIL.”

^Abased on independent testing of AMSOIL Signature Series 0W-20 using the ASTM D6891 standard 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. ^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. ^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. ^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. ^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. ^CBased on independent testing of AMSOIL Signature Series 5W-30 in the GM turbo coking test. ^PPBased on independent third-party testing in the industry standard ASTM D5293 Cold Crank Simulator test as required by SAE J300. ^BBased on zero LSPI events in five consecutive tests of AMSOIL Signature Series Motor Oil in the LSPI engine test required by the GM dexos1 Gen 2 specification.