Viscosity vs. Sheer strength are similar, but Red Line handles high loads better. There is no longer a problem with synthetic lubricants eating away seals. Red Line blends its lubricants, but does not manufacture the synthetic bases. The moly provides a dry-film lubrication. Gear Oil Gear oil viscosity is measured at 150 F vs. 210 F for motor oil.
Gear oil is acidic, motor oil is alkiline.
Therefore, it has a very high sulfer and phospor content. Sulfur and Phosphate reactions start at a lower temperature, and Gear Oil has much more additive than motor oil. This additive is corrosive to copper bearings and bronze synchro rings. Positraction additives are Friction modifiers - make the base oil much more slippery. Friction Modifiers may detract from EP characteristics.