DOT is short for US Department of Transportation. The Federal Motor Vehicle Safety Standards (FMVSS) classifies three main grades of brake fluids under FMVSS 116. These grades are DOT 3, DOT 4, and DOT 5. These standards dictate specifications such as minimum ERPB, maximum wet ERPB, maximum and minimum kinematic viscosity, base components and color. Our brake fluids all meet or exceed these federal standards.