If your car is low on freon, you may be wondering how much you need to put in. The amount of freon needed will depend on the size of your car's engine and the type of refrigerant used. Most cars use R-134a refrigerant, which requires about 2 ounces per square inch of engine displacement. To calculate the amount of freon needed, first find the size of your car's engine in cubic inches. For example, a 4-cylinder engine with a displacement of 200 cubic inches would require 400 ounces (200 x 2) of R-134a refrigerant.
If you're not sure what type of refrigerant your car uses, check the owner's manual or ask a qualified automotive technician. Once you know the type and amount of refrigerant needed, purchase it from an auto parts store or online retailer. Be sure to follow all instructions carefully when adding freon to your car's air conditioning system.