antifreeze serum

Many listings are sold premixed at a 50/50 ratio and are ready to use for topping off. Others are concentrates that must be mixed with water to the correct dilution for a full flush/fill or for topping off after mixing.

Several premixed formulations advertise freeze protection down to about −34°F and boiling protection up to about 265°F. Specific protection ranges vary by product, so check each listing for exact values.

Listings show several chemistry labels, including Hybrid Organic Acid Technology (HOAT), Si‑Organic Acid Technology (Si‑OAT), Inorganic Additive Technology (IAT), and other carboxylate/HOAT variants, depending on the formulation.

Formulations are described as protecting all cooling‑system metals (including aluminum) and helping keep radiators and water pumps clean; some listings also note they won’t harm gaskets, hoses, and plastics.

Premixed 50/50 formulas are ready to use for topping off. Concentrate formulas should be mixed to the correct dilution before use—either for a complete flush/fill or for topping off after mixing.