No Electrolysis


One of the most-asked questions we get at Evans is regarding how waterless coolant prevents cooling system-damaging electrolysis. Evans Cooling Systems (ECS) has always contended that the absence of water in a cooling system dramatically reduces the likelihood of electrolysis-related issues in the cooling systems.


Electrolysis damage in an engine cooling system is caused by unintended electrical currents that flow from voltage differences that exist in the engine coolant jacket, the radiator, and the heater core. The damage can include rapid corrosion, pitting, flaking, and pinholes. The voltage differences may result from poorly grounded electrical equipment that has a stray voltage problem.

Another source of cooling system voltages is from the action of dissimilar metals with which the coolant is in contact. Metals and alloys that are different from each other have different electrode potentials. When two of them come into contact in an electrolyte, one acts as a cathode and the other as an anode. The engine coolant is the electrolyte. The metals need not be physically touching, as the engine coolant is the conductive path for an ionic transfer. The ionic transfer causes erosion and pitting of metal, or electrolysis damage.


Regardless of the source of the voltage differences, the amount of current flow determines the damage potential. The conductivity of the coolant is directly related to the rate of ionic transfer. It is measured in microsiemans per cm (μS/cm). Coolant that is 50% water has an electrical conductivity of about 3000 μS/cm. In contrast, Evans waterless coolants typically measure just 700 μS/cm. The substantially reduced electrical conductivity of the Evans coolant sharply reduces incidents of electrolysis.