Selecting the correct synthetic gear oil is made difficult not only because of the different types of synthetic lubricants available, but also the question: why should I move away from mineral based oil?
Synthetic base oils, unlike their petroleum counterparts, are built from the molecular level. The molecules can be manipulated to improve specific lubrication characteristics. With their consistent and predictable chemical structures, and exceptional performance profiles, synthetic oils are displacing petroleum oils that can no longer meet the needs of demanding applications.
The best known of the synthetic oils' advantages is their ability to function at both very low and very high temperatures. In fact, engineers typically turn to synthetic oils because of extremes in operating temperatur e. Sometimes these limitations can be overcome by lubricant additives, but many additives are expensive or contain undesirable components. In general, it is far more efficient to use an optimal base oil--and use additives to enhance specific performance features--than to try to make up for a base oil's shortcomings with additives.