What happens when you put coolant in a gas tank?

Putting coolant in a gas tank can cause significant damage to the vehicle's fuel system and engine. Coolant is not combustible like gasoline, leading to poor engine performance, possible fuel system blockage, and even engine failure. The engine may misfire or stall, and extensive repairs may be necessary to clean out the fuel system and replace damaged components. If this happens, it's crucial to have the vehicle towed to a mechanic for proper assessment and repair.