Q: Wondering whether I can use prestone 5050 antifreeze coolant instead of fl22.?

While the green coolant or "safe for use in all vehicles" type coolants may be less expensive than what is in your cooling system, I HIGHLY recommend you do not mix them. Different coolants have different chemical properties. They can become slightly acidic or begin to gel when combined. It doesn’t happen immediately but will occur over time. This can cause coolant leaks as well as clog the small coolant passages in the engine, radiator, and heater core. Even adding a small amount of a different coolant can cause these issues. If you have already added a different coolant, I recommend flushing the cooling system and refilling it with the correct coolant only.