Millers Oils Alpine Red Antifreeze & Coolant 5L (Concentrate)

It is highly recommended not to mix different coolant chemistries such as OAT, HOAT, or IAT. Mixing incompatible coolants can cause a severe chemical reaction that forms a thick, gel‑like sludge which can clog the radiator, heater core, and water pump, leading to catastrophic engine overheating. If you must switch to a different formulation, perform a complete system flush first and follow the vehicle manufacturer’s coolant specification and service procedure.

That depends on whether you purchased a "Concentrate" or a "Ready-to-Use" (Premixed) formula. If you bought a Concentrate, you must dilute it—typically at a 50/50 ratio using strictly distilled or deionized water to prevent internal mineral scale buildup. If you purchased a Ready-to-Use or Premixed bottle, it is already perfectly diluted at the factory and should be poured directly into your cooling system without adding any water.

Replacement intervals vary widely depending on your vehicle make and the specific chemistry of the coolant. Traditional (older) coolants usually require changing every 2 years or 30,000 miles. However, modern premium Extended Life Coolants (OAT or HOAT) used in most newer vehicles are designed to last anywhere from 5 years/150,000 miles up to the lifetime of the vehicle. Always check your owner's manual for the exact recommended interval.

Over time, the critical anti-corrosion inhibitors inside the coolant break down. Visual signs of degradation include a murky, rusty, or brownish appearance in your overflow reservoir, or visible floating debris. Mechanical signs include your engine temperature gauge running higher than normal, your cabin heater failing to blow hot air, or a sickly-sweet syrup smell coming from the engine bay.