If you're looking to top off your coolant, you may be wondering if it's okay to mix different types of antifreeze. After all, many automotive fluids are interchangeable. However, it's not recommended that you mix Hoat (hybrid organic acid technology) with regular antifreeze.
Hoat is a newer type of antifreeze that contains both traditional ingredients like ethylene glycol and new organic acids. This combination provides better protection against corrosion than either ingredient alone. Additionally, Hoat doesn't need to be changed as often as regular antifreeze - typically every four years or 100,000 miles.
Because Hoat is a newer product, most vehicles on the road still use regular antifreeze. Mixing the two types can result in decreased performance from your cooling system and potentially cause long-term damage. If you need to add coolant and don't know what type your vehicle uses, it's best to play it safe and stick with the same kind that's already in there.