The kind of coolant your car takes depends on the specific type recommended by the vehicle manufacturer, which is best found in your owner's manual. There are several main types of engine coolants commonly used:
- IAT (Inorganic Additive Technology), usually green, common in older cars, needs changing every 2 years or 24,000 miles.
- OAT (Organic Acid Technology), often orange, red, pink, yellow or purple, used in many modern vehicles, typically changed every 5 years or 50,000 miles.
- HOAT (Hybrid Organic Acid Technology), usually yellow or turquoise, combines features of IAT and OAT and is common in Ford, Chrysler, and some European vehicles; also changed every 5 years or 50,000 miles but sometimes longer intervals.
Using the wrong coolant type can cause engine damage, corrosion, or clogging, so it is critical to consult your owner's manual or vehicle-specific guide. Coolants come pre-mixed or as concentrates and are usually mixed 50/50 with distilled water. Color can vary by brand and type but always follow manufacturer recommendations for compatibility.