The Lobrid (Low Hybrid OAT) / Si-OAT Technology Antifreeze is a specialized, modern engine coolant that represents the latest evolution of Hybrid Organic Acid Technology (HOAT).
Definition
Lobrid Antifreeze, often referred to as Si-OAT (Silicate Hybrid Organic Acid Technology), is an extended-life coolant that utilizes a combination of corrosion inhibitors: a primary blend of Organic Acid Technology (OAT) compounds and a very low concentration of silicate additives. The term “Lobrid” (Low Hybrid) is derived from this characteristic of using a lower level of the inorganic silicate component compared to earlier HOAT formulations.
Properties and Applications
- Dual-Action Protection: The core benefit lies in combining the rapid, localized corrosion protection of silicates with the long-lasting, depleted-rate protection of organic acids. The silicates quickly form a protective film, especially on aluminum surfaces, while the OAT compounds provide sustained, systemic corrosion resistance over the coolant’s lifetime.
- Targeted Market (Europe): Si-OAT/Lobrid coolants are primarily specified by European vehicle manufacturers, including major brands like Volkswagen (VW TL 774-G / G12++ specifications), Audi, Mercedes-Benz, and Porsche. This preference is due to the excellent performance of silicates in protecting aluminum components, which are prevalent in modern European engines, and the formulation’s superior stability in hard water regions (unlike P-HOAT).
- Long Service Life: These coolants are designed for very long service intervals, often rated for 5 years or more, or up to 250,000 km in passenger cars, and even longer in commercial vehicles. This extended life is a key advantage of the OAT base.
- Silicate Stability: The “Lobrid” design uses special stabilizer packages to ensure the low silicate content remains dissolved and active, preventing it from precipitating out of the solution, which was a common issue with older, high-silicate IAT coolants. This contributes to exceptional hard water stability.
- Chemical Composition: Si-OAT formulations are typically free from other inorganic inhibitors like nitrites, amines, phosphates, and borates, focusing instead on the blend of carboxylates (OAT) and stabilized silicates.
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Appearance: The color of Lobrid/Si-OAT coolants is often specified as magenta, violet, or pink, though this can vary by manufacturer.
