Poly-Alpha-Olefins (PAO)

22 june 2011

Question: Why poly-alpha-olefins are true 100% synthetic?

MITASU OIL expert opinion: To understand variety and classifications of motor oil it is worth noting that any motor oil consists of two main ingredients: one type or blended mixture base stock, combined with a unique system of enhancing additives (performance additives). There are four different types of base stock used for motor oil production: mineral oil of Groups I and II and oil of Groups III and IV. Group III is marked as "synthetic base stocks" although they may be derived from natural products by highest level of refining. Group IV base oils are poly-alpha-olefins (PAO) - chemically engineered synthetic base stocks.

Question: What is the main difference between poly-alpha-olefins and other groups of base stocks?

MITASU OIL expert opinion: Let’s consider the four most important properties of motor oil and draw a comparison between poly-alpha-olefin (PAO) based motor oil and motor oils from other groups:

– Freezing point (pour point)

Group IV has a lower freezing temperature than Group III and even without depressant additives (capable to lower freezing point even in mineral oil) it allows to keep the pour point temperature down to -50°C and lower.

– Cold start

PAO based motor oils are ideal for use at low temperature conditions. The original property of these oils - high viscosity index, provides smooth engine start, even at extremely low temperatures. Almost all motor oils classified as 0W-30, 0W-40 are formulated with Group IV base stock.

– Drain interval and fuel efficiency

Absence of small size molecules in poly-alpha-olefins minimises their evaporation loss. Inclusion of poly-alpha-olefins in motor oil formula significantly reduces evaporation rates and effectively decreases consumption of engine oil. In addition, modern Group III and Group IV base oils ensure fuel economy. The main line of modern products by Mitasu Oil Corporation is Group III and Group IV motor oils; some are classified as resource conserving and marked with API (American Petroleum Institute) Resource Conserving service symbol.

– Protection from oxidation and thermal stability

Extended service life is one of the most important properties of MITASU motor oils formulated with poly-alpha-olefin (PAO). This means extended drain interval for engine oil and for some products the oil change interval can be extended up to 30,000km!

Because poly-alpha-olefins are synthesised in laboratories they have significantly better homogeneity and effectively much higher resistance to ageing. Preceding groups base oils are more susceptible to oxidation and their additive package has limited potential. Poly-alpha-olefins are less susceptible to these processes. Thus, the group IV base oil has a longer life and greater operational stability by default, even without the use of performance additives.

– Environment and protection of exhaust catalyst

Environmental regulations have forced automotive manufacturers to develop much more sophisticated catalytic converters. Therefore oil and fuel used must be in compliance with modern exhaust treatment systems. Poly-alpha-olefins and, in particular, the latest motor oils classified API SN ILSAC GF-5 specially designed to not only improve the environmental performance but also to protect the exhaust system catalyst.