AMSOIL Crushes Sequence IIIH Engine Test

We always look forward to the development of new, more demanding, oil specifications. It means the availability of new performance tests – and new ways to test our products – which excites the whole AMSOIL technical development team.

After more than a year of delays, the new API SP and ILSAC GF-6 motor oil specifications took effect May 1. Their introduction continues the trend of more demanding specs to ensure today’s motor oils are capable of protecting advanced engines.

AMSOIL Signature Series Synthetic Motor Oil achieved great results in one of the new engine tests needed to meet API SP and ILSAC GF-6 requirements – the Sequence IIIH Test.

But that’s just part of the story. Let’s peel back the curtain and see how it all happened.

Sequence IIIH motor oil test.

Pushing oil to its breaking point

The Sequence IIIH test is designed to measure viscosity increase and piston cleanliness, two important differentiators of motor oil performance.

It subjects a candidate oil to 90 hours of use at 304ºF (151ºC) in a Chrysler* engine, much hotter than normal operation to really challenge the oil. The intent is to screen oils for their ability to maintain protection under the severe conditions today’s smaller, hotter-running turbocharged engines present.

Simply put, it’s designed to push the oil to its breaking point and separate those that can protect from those that can’t.

Sequence IIIH Test no match for Signature Series

As soon as the test stand was available, we sent samples of Signature Series to an independent lab that specializes in testing motor oils from all kinds of manufacturers.

The lab techs do nothing but test oil all day, every day. They’re accustomed to testing oils designed to just barely pass these performance tests, so when they heard AMSOIL Signature Series was going to be tested, their ears perked up. Many of them are gearheads who use AMSOIL products themselves, so they wanted to see the results.

The 90-hour test didn’t even challenge Signature Series. Its viscosity increased only 0.1 percent and the pistons were so clean they looked practically new.

Signature Series resists viscosity increase

Double-length Sequence IIIH Test no match, either

So, we told the lab to reassemble the engine and run the test again using the same oil, doubling the length of time on the engine and oil to 180 hours.

As the test neared its conclusion, the lab manager said the techs were lined up in the test cell to watch the engine run…and some were even taking pictures.

Following the test, oil viscosity was measured and the pistons were rated for cleanliness. Even after doubling the length of the industry-standard test, Signature Series limited oil thickening to 49.6 percent – half the allowable limit of 100 percent for a single-length run – while delivering 40 percent cleaner pistons.¹

Needless to say, the techs were impressed.

AMSOIL keeps pistons cleaner

How did the oil achieve such impressive results?

We start with the best synthetic base oils available, which naturally resist chemical break down in the presence of extreme heat. We add a finely tuned, high-quality additive package designed to complement and enhance the base oils’ performance.

Increased levels of highly active detergent and dispersant additives control contaminants and keep engine parts clean. The premium base oils combined with the right balance of anti-oxidant additives also control viscosity, helping the oil stay in grade despite prolonged exposure to brutal heat.

This adds up to premium engine protection in today’s demanding engines. Signature Series protects vital components against wear in the toughest conditions, providing motorists peace of mind and giving them the confidence to extend drain intervals if they choose.

AMSOIL Signature Series

When a competitor’s oil easily passes an industry-standard test, they often reformulate to reduce cost and performance to where it barely passes the test. When we pass a test (or a double-length test), we continue to search for ways to increase protection even more because, for our customers, “good enough” doesn’t cut it.

Our goal is to provide enthusiasts the absolute best motor oil on the market, and our team gets excited about the testing to prove it. It’s not easy to impress the professionals that test motor oil for a living, but Signature Series delivered.

¹Based 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.


  1. All of the manufacturers make oils that far exceed specifications whether it be Pennzoil Ultra Platinum, Mobil 1 or Castrol Edge. In fact, your own product testing shows this. Pennzoil claims 65% cleaner pistons than industry standard IIIH test. Mobil 1 is in some of the highest performance cars in the world and in 50% of Nascar teams. What you’re referring to are likely the mainstream, mid to low tier synthetic oils.

  2. “When a competitor’s oil easily passes an industry-standard test, they often reformulate to reduce cost and performance to where it barely passes the test.”

    That’s a pretty bold accusation. What proof of that do you have?

    1. Hi MVlo,

      First, look at the head-to-head comparisons between AMSOIL products and other lubricants. A good example is cold-temperature performance, which is an expensive feature to include in an oil formulation. This gear-lube test is a good example. The Mobil 1 product failed to meet the industry standard, the Valvoline product snuck in just under the requirement while AMSOIL SEVERE GEAR delivered the best cold-flow performance.

      Second, we receive feedback from some of our raw-material suppliers that they love working with us because they can target performance instead of always focusing on reducing costs. Given our performance against other oils and the feedback we get from suppliers, we’re confident that no one is targeting higher levels of performance despite the costs like us.



  3. Can you tell me how much does it cost to have oil tested I have a 2012 Dodge Ram with 86000 miles an 3786 hours on it thank you

  4. What MORE can you say about the BEST SYNTHETIC MOTOR OIL ON THE U.S.A.MARKET!!! I have seen AMSOIL perform in a race car for over three racing seasons with NO OVERHAUL. AND WAS STILL RUNNING STRONG. This all happened in Fairbanks Alaska in 1982- 83- 84 . And was sold too another driver who ran it half of the next season before losing the coolant and not watching the temp. gauge.

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