Transmission Fluid Viscosity

Viscosity is a measure of an oil’s resistance to flow at various temperatures. The SAE Viscosity Grade system is defined in SAE Standard J306 for gear oils such as transmission fluid that designates a viscosity range with a grade number. Lubricants with two grade numbers separated by a “W,” such as 75W-90, are classified as multigrade. Lubricants with a single number are monograde. The higher the number, the higher the viscosity. The lower the number, the lower the viscosity.

Use only Detroit® approved transmission fluids. For optimal fuel economy, use the lowest recommended viscosity for an application. (See Section “Transmission Fluid Applications Factory Fill and Service Fill”).

Document Number:0000050533