Motor oils are comprised of two parts, the base oil and additive package. The base oil comprises 80-90% of the oil by volume and the additives the remaining 10-20%. There are five groups of base oils: Group I, II, III, IV and V. Groups I to III are refined from crude oil containing tars, asphalts, waxes, aromatics and other "bad things". These crude oils are "cleaned up", to the extent possible, by hydrocracking, filtering and hydroisomerization. The group III base oils are the best of this genre. However, they still contain variably-sized molecules and some contaminants that can result in sludge, varnish and other deposits in your engine. Moreover, the quality of group III base oils vary greatly due to differences in the combination of feedstocks and refining methods utilized.

Synthetic oils are group IV Polyalphaolefins (PAOs) and group V (esters) base oils. Both pao-oil and ester oil are synthetic oils that are "man-made" synthesized uniform molecular structures that significantly improve the efficiency and effectiveness of these oils relative to their petroleum oil competitors. More specifically, these synthetic oils have significantly lower coefficients of friction, thermal (heat) and pour-point (cold weather performance) properties than do petroleum oils. Finally, synthetic oils have no waxes, tars, or other contaminants to sludge or varnish your engine.

While synthetic lubricants are initially more expensive, when you consider their extended oil and engine-life extension capabilities, in addition to their improved performance, then you have only one choice and that choice is synthetic oil, and that oil is AMSOIL. These oils are definitively the best synthetic motor oil.

Petroleum oils are produced in an oil refinery, where crude oil is separated into fractions. These fractions become the basis for lubricating oils and fuels. Thick tangled masses of carbon chains become asphaltic materials used in roofing tar and road work; whereas, short molecular chain and ring compounds of carbon are volatile and can be refined into gasoline and other types of products.

Petroleum refining is a complex science, wherein, contaminants, as mentioned earlier; including sulfur and other reactive hydrocarbons, cannot be completely removed from the crude oil. Thus, these contaminants remain in petroleum oil base stocks.

The advantages of AMSOIL are hardly limited to extreme conditions, but rather from their strength in day-to-day use. At the core of AMSOIL's synthetic lubricants is the ability to provide superior lubrication. That means engines and machinery operate more efficiently, with less friction. Less friction means less heat produced and less wear and tear on mechanical parts, which allow engines and machinery to have much longer life spans. The increase in operating efficiency also means an increase in power and fuel efficiency, since your equipment is not fighting against itself and friction.

AMSOIL is one of the least expensive and smartest investments you will ever make to insure that your motorized equipment will run the longest with the least amount of maintenance and the highest fuel efficiency. Lubricating oils are the lifeblood of mechanical equipment, and are the single most determining factor in how long your equipment will last, and what the costs of maintaining that equipment will be.