There's more to lubricating your engine and drive train than motor oil. Differentials and transmissions need lubrication too, and gear oil faces very different challenges. Understanding the difference is an important way to help boost your performance, especially if you're looking for ways to improve gas mileage.
Instead of the sliding friction of pistons, gear oil has to deal with the pressure of metal parts pushing against each other. Viscosity is the key to a good gear oil. Higher viscosity resists "sling-off," where the gears' centrifugal force tries to throw the gear oil away from where it's needed. It also means a more stable lubricating film to prevent pitting and scoring of the gear teeth. The problem is that higher viscosity also causes drag that absorbs power and reduces fuel efficiency. The trick is to hit just the right viscosity, but not so much that you waste engine power.
That kind of precise formulation is why synthetic gear oil is a better choice than conventional lubricants. AMSOIL offers a line of synthetic gear oils that takes advantage of the precise formulation possible with synthetics to achieve very specific viscosities.
For automotive applications, AMSOIL's SA 80W-90 (AGL) exceeds the standards, with extra additives designed to improve protection and double the life of the oil. Its thermal control additives help resist "thermal runaway," a vicious cycle of temperature increases and viscosity loss that can result in catastrophic failure of the gears. AMSOIL's 80W-90 synthetic gear oil is meant for light and heavy duty automotive applications, in differentials, transaxles, manual transmissions and oil lubricated wheel bearings. It's also one of the best ways to improve gas mileage as it passes more of your engine's power to the wheels.
Working and Tow Vehicles
For high torque applications, AMSOIL offers a line of Severe Gear Extreme Pressure synthetic gear oils in several grades. AMSOIL's 75W-90 (SVG), 75W-110 (SVT) and 75W-140 (SVO) are intended for hard working vehicles that have to carry heavy loads under rough conditions. They're the ideal gear oil for heavy pickups, motor homes, tow trucks, heavy equipment and commercial fleet vehicles. AMSOIL's Severe Gear Extreme Pressure line is designed to deal with heavy loads, steep driving conditions, and high temperatures.
Off-Road and Racing Vehicles
In the most demanding gear oil applications, AMSOIL's Severe Gear Synthetic SAE 190 (SRN) and SAE 250 (SRT) can handle the pressure. Meant for extremely high horsepower and torque conditions, these gear oils are specifically designed to resist sling-off and to keep working under high G-forces and extreme pressures . For sports like truck racing, off-road racing and drag racing, AMSOIL Severe Gear synthetic gear oils are designed to stay where they're needed and protect critical parts.