Brake fluids for modern systems are designed for vehicles equipped with electronic assistants such as ABS (Anti-lock Braking System) and ESP (Electronic Stability Program). For their proper function, these systems require a low-viscosity fluid. Viscosity is a quantity describing the internal friction of a fluid, in layman's terms its 'thickness' and ability to flow. Low-viscosity fluids are more liquid and move faster within the hydraulic brake system. This is crucial because ABS and ESP systems operate with very rapid changes in braking pressure, in the order of milliseconds. A low-viscosity fluid can instantly react to the control unit's commands and flow through narrow channels and valves even at low temperatures, when conventional fluids thicken and slow down the system's reaction.