What Coolant is Right for My German Automobile?

Whether you drive a BMW, Porsche, Mercedes Benz, Audi, Mini or Volkswagen, your vehicle circulates a mixture of water and coolant to dissipate the heat generated within your engine—preventing it from having a total melt down (one notable exception are older Porsche models that are air and oil cooled and did not use water or coolant, but instead circulated a large amount of oil to dissipate the heat).

A Rainbow of Colors:

There are a lot of coolant types to choose from—so which is right for your BMW, Porsche, Mercedes Benz, Audi or Volkswagen? The answer is the type that came in your vehicle originally. Although depending on the manufacturer, your coolant may be green, pink, blue, yellow or even clear. All coolants are naturally clear and the color is created with dye.  Each manufacturer puts their own dye mixture into their coolant—it does not affect the chemical characteristics of the coolant. European manufacturers prefer coolant that is phosphate-free because the water in Europe is much harder than the water here in the United States.

There are three basic coolant types on the market today: (IAT) Inorganic Acid Technology, (OAT) Organic Acid Technology and (HOAT) Hybrid Organic Acid Technology. Your BMW, Porsche, Mercedes Benz, Audi or Volkswagen uses an HOAT coolant.

HOAT coolants are derived from OAT coolants with the addition of silicate to protect aluminum surfaces. Many components of your BMW, Mercedes Benz, Porsche, Audi and Volkswagen engine and cooling systems are made of aluminum including the cylinder heads and radiators.

OAT coolants do not use silicate and phosphate corrosion inhibitors. These coolants have an extended service life and are designed for 150,000 miles of service (or 5 years). Although it should be noted that German Auto Center and most manufacturers recommend flushing or changing the coolant every two years.

Traditional coolants are IAT coolants and uses silicate and phosphate corrosion inhibitors to protect the metal (Iron) parts of the engine and cooling system. As your BMW, Mercedes Benz, Porsche, Mini, Audi and Volkswagen have replaced most iron components with aluminum and other lighter composites, IAT coolants should not be used.

Although you can mix coolant types without harm, it is highly recommended that you do not.  Mixing an HOAT or OAT coolant with an IAT will lose the extended life properties. Please feel free to stop in and see the experts at German Auto Center if you have any questions. In addition, there are many online resources for auto diagnosis & auto repair help such as AA1Car.com.

Whether you drive a Porsche, Mercedes Benz, Mini BMW, Volkswagen or Audi, It is important to remember that with proper maintenance, today’s German performance vehicles will serve you for many miles and years to come. Visit Austin German automobile repair experts at German Auto Center. We will be happy to assist you!