Benefits of a PAO Ester

Have you ever wondered what is the difference between synthetic, full synthetic and a PAO
synthetic? You’re not alone – the naming of lubricants has created a confusing array of terms and
this makes it difficult to understand the differences between technology and marketing hype.
Polyalphaolefins (PAO) are “true” synthetic base oils – i.e. they are constructed from the reaction
of smaller molecules rather than refined from crude oils. They have long been regarded as the gold
standard for engine oils and this awards them the status of Group IV, a group that they do not
share with any other base oil type. As they contain far fewer undesirable molecules than Group II
mineral oils and Group III synthetics they actually solve a range of issues that are prevalent in
high performance engines.
For example – higher viscosity oils help to protect engine components, so why don’t we don’t all
use 30W-70? The problem is friction; thick oils require more energy to circulate around the engine,
and this means a smaller percentage of combustion power reaches the road. But oil viscosity is only
half the story. There is another parasitic loss called “traction”; this is the “internal friction”
of oil molecules sliding past each other. True synthetic PAOs have such regular sizes and shapes
that they easily flow past each other, reducing the amount of waste heat generated and increasing
engine power delivery.
Just as honey thins out at high temperatures, so do engine oils. Standard engine oils require the
addition of viscosity improvers to maintain oil viscosity under engine operating conditions. Over
time these are susceptible to shearing in the engine, especially in highly loaded performance
engines. PAOs have naturally high viscosity indexes so the engine oils require fewer additives to
manage viscosity; this allows them to remain in specification for longer even under challenging
conditions.
The opposite is true of cold temperatures – oils don’t freeze like water because they consist of a
basket of molecules with different freezing points, but they do gel causing flow restriction at low
temperatures. PAO’s exhibit excellent low temperature and pour point characteristics to offer
maximum engine protection on startup, even in cold environments.
Heat destroys lubricants. Extreme temperature conditions typically encountered in areas such as the
top ring groove and piston undercrown cause the base oil to
thermally degrade. Coupled with oxidation, this creates sludge and varnish