Red Line Synthetic ShockProofGear Oil provides unequalled protection for high-performance differentials and transmissions which are heavily loaded or which see shock-loading. This revolutionary lubricant is completely different from conventional lubricant technology in several ways. The viscosity characteristics are significantly improved. Gear teeth need high viscosity at high temperatures to prevent metal-to-metal contact and a low viscosity when cold to reduce fluid friction. The ShockProofchemistry significantly reduces the thinning effect of high-temperatures. The Heavy can be rated as a 75W250 Gear Oil, but has the lower internal fluid friction of an SAE 75W90. The LightWeight can be rated as a 75W140 Gear Oil, but has the lower internal fluid friction of an SAE 30 motor oil. The SuperLight can be rated as a 70W90 Gear Oil, but has the lower internal fluid friction of an ATF.