To know for sure, you need to:
* Check your owner's manual: This is the most reliable source of information. The manual will specify the correct refrigerant type for your specific year and model of Ford Fusion.
* Look at a sticker on the AC system: Sometimes there's a sticker on the AC compressor or other component that indicates the refrigerant type.
Using the wrong refrigerant can damage your AC system. It's best to consult your owner's manual or a qualified mechanic.