Polyalphaolefins - One of the synthetic hydrocarbon liquids manufactured from the monomer ethylene, H2C=CH2. Polyalphaolefins have a complex branched structure with an olefin bond in the alpha position of one of the branches. Hydrogenated polyalphaolefins have olefin-carbons saturated with hydrogen, which lends excellent thermal stability to the molecule. Synthetic-base fluids (similar to oil muds) are made with the various types of synthetic liquids because the cuttings can be discharged in offshore waters, whereas discharge of cuttings coated with refined oils would be disallowed.
Now that that is out of the way, let's start. Because of the nature of this base stock I am going to be specific. For this article I had some in depth confirmation with AMSOIL.
Let's get started.
PAO synthetic base oils start with a specified petrochemical feedstock which is then completely changed chemically; a brand new product is designed and created through a chemical reaction process.
You start with ethylene, grow it to make an alphaolefin and finish with a final chemical reaction - polymerization and hydrogenation - to make a defined set of molecules, PAOs. Lower molecular weight materials are changed into higher weights. That's the key. The desired molecular structure is designed in advance and then manufactured to explicit specifications. You end up with base oil which is absolutely consistent from batch to batch and provides performance properties - in low temperature starting and pumping, volatility, and wear protection, improved fuel economy - that cannot be matched by base oil produced by either other process, whether its solvent refined or hydroprocessed.
Consistency is the most important. An example is when an umpire substitutes a baseball into a game after a home run is hit, that baseball is exactly like the one that was hit out of the park. However, if you mix baseballs with softballs, golf balls, tennis balls or billiard balls, you do not have the equivalent of PAO. But you do have the equivalent of a mineral oil refined by solvent extraction or hydroprocessing.
The hydrocracked base stocks come marketed as Very High Viscosity Index (VHVI) base stocks, but are not made by a synthetic process that starts with specific raw material which is built to produce a specific end product. While they are definitely better than solvent refined base oil, don't be mislead as they don't have the performance properties of PAOs.
Now with all that being said one of the most important features of a PAO oil is the fact that they can be ran in most engines for an extended amount of time. It is not uncommon at all to hear 25 to 30 thousand mile intervals between oil changes.
About the Author
Tony Manning is an Independent Sales Rep for AMSOIL Synthetic Motor Oil. He has well over 20 years of automotive service, automotive parts retail and automotive racing. He manages one of the most visited AMSOIL websites: http://www.SynMotors.com and can be contacted at email@example.com for any questions that you might have.