AMSOIL XL Synthetic Motor Oils are engineered to overcome the main reasons for motor oil failure.
Their extended-drain additive boost is designed to impart long oil life.
Dan Peterson | AMSOIL TECHNICAL DIRECTOR
I was taught early in my engineering career, “In God we trust; all others, bring data.” I have to chuckle a little every time I tell someone about my deep-seated belief that I will not accept any conclusions on a technical subject without being fully backed up by unbiased data.
I think it might even get a little irritating hearing me continually ask, “Where is your data?” I know many AMSOIL Dealers and customers feel the same way; they want the facts before accepting things as foregone conclusions. Dealers depend on solid technical data to provide customers the best possible solutions to technical problems. They know that when you become a solid technical resource to customers, you increase your value and credibility in the customers’ eyes. The monthly Tech Talk column will provide solid technical facts for people who really want to know.
This inaugural issue of AMSOIL Magazine features the introduction of the re-formulated XL line of oils with boosted extended-drain capabilities. The first question many people ask is, “what imparts XL’s extended-drain abilities?”
First, you need to understand what prevents an oil from providing adequate protection over an extended period of time. Two common failure modes for passenger car motor oils are oxidation and acid build-up. Oxidation causes oil viscosity increase, sludge, varnish and hard carbon deposits. These effects can restrict oil flow and stick piston rings, leading up to catastrophic engine damage.
Acid build-up in the oil sump occurs from oxidation, combustion by-products and other contaminants. Over time, an oil’s ability to neutralize acids is reduced and, eventually, the detergent system is unable to combat deposits. Corrosive wear can occur in bearing materials and other critical areas, and excessive deposits can form. If an oil is to be used for extended drain intervals it must successfully address the issues of abnormal
viscosity increase and excessive acid build-up over the specified interval.
AMSOIL XL Synthetic Motor Oils are designed to overcome these common oil failure modes. Highly saturated synthetic molecules have been proven to do a superior job handling heat and resisting oxidation. Unlike conventional oil molecules, pure, uniform synthetic molecules are manufactured with more stable chemical groups that actually block oxygen and other contaminants from attaching to the base oil chain, resulting in more stable viscosity levels for longer periods of time.
Well-designed anti-oxidants enhance resistance to chemical attack and provide an added layer of protection against sludge development. Many of these materials work by proactively attaching to oxygen molecules and contaminants and consuming them in an oxidation reaction. This effectively prevents these viscosity-increasing materials from attaching to the backbone of the base oils. Basically, anti-oxidants slow down the oxidation process by tying up free radical materials.
Acid build-up and detergent levels are measured by two different variables: total base number (TBN) and total acid number (TAN). TBN is a measure of the remaining detergent or acid-neutralizing capability of an engine oil. TAN is a measure of acid build-up in the system. As TBN levels are naturally depleted over time, TAN levels increase. With extended drain interval oils, the detergent level is boosted to keep acids in check over the extended period between oil changes.
The XL series features a new extended drain additive boost designed in part to increase the oil’s starting TBN levels and enhance TBN retention to safely provide excellent lubrication for up to 10,000 miles and beyond. The XL line is also designed with premium synthetic base oils and an anti-oxidant system that safely resists chemical attack over this period.

From Michael Sparks:
“Confronting the Challenging Lubricant market head on with ongoing product testing, reformulation, higher performance and cost effectiveness is AMSOIL’s Forte. ” There is not other company that provides such a broad array or products like motor oils, gear and transmission lubes, greases, filters, bypass systems and other automotive related products. This is why AMSOIL is “The First in Synthetics”
Michael Sparks-AMSOIL Dealer / Direct Jobber
lube-direct.com