The quickest way to find out what refrigerant your car uses is to read the A/C refrigerant charge label under the hood. Look for “R-134a” or “R-1234yf” and note the specified charge amount. Do not choose refrigerant from the vehicle’s model year alone: the same model line can use different refrigerants depending on its build date, engine, factory, or market. If the label is missing or unreadable, stop before buying or connecting a can. Check the owner’s manual or factory service information, or ask a dealer or qualified A/C shop to look up the specification by VIN. The label on the vehicle remains the best first check. Where to Find the Car A/C Refrigerant Label Open the hood and look for an A/C information or refrigerant charge label. It is commonly attached to the underside of the hood, radiator support, front crossmember, or another visible surface in the engine compartment. The exact location varies by vehicle. A useful label normally gives you more than the refrigerant name. Record these details before ordering anything: Refrigerant type: usually R-134a or R-1234yf on modern U.S. passenger vehicles. Charge amount: shown by weight, often in grams and sometimes ounces. Lubricant specification: the required compressor oil may also appear on the label. Warnings: an R-1234yf label includes safety markings required for that mildly flammable A2L refrigerant. General Motors, for example, directs technicians to the vehicle’s A/C refrigerant charge label for proper identification because not every vehicle within a listed model range necessarily uses the same refrigerant. That is why a model-year chart should be treated as a clue, not proof. R134a or R1234yf: What the Label Means Label says What to buy Important service point R-134a or HFC-134a R134a that matches the container and purchaser requirements for your intended use Use R134a-compatible equipment and the oil specified by the vehicle manufacturer R-1234yf or HFO-1234yf R1234yf Use R1234yf-specific fittings, equipment, procedures, and the specified compressor oil R-12, R-744, or another refrigerant Do not substitute R134a or R1234yf based on appearance Confirm the approved refrigerant and service procedure for that exact system R134a was the most common refrigerant in U.S. motor-vehicle A/C systems beginning in the 1990s. R1234yf later became the dominant refrigerant in newer light-duty vehicles. The transition did not occur on one universal model-year cutoff, so statements such as “all cars after year X use R1234yf” are unreliable. For a closer look at the two refrigerants, see our R134a vs. R1234yf comparison . Can R134a and R1234yf Be Interchanged? No. Do not mix them or use an adapter to force one refrigerant into the other system. The U.S. Environmental Protection Agency requires unique fittings for each approved motor-vehicle refrigerant to help prevent accidental mixing. EPA also states that an adapter may not be used to convert a fitting. The different connectors are not an invitation to improvise. R1234yf systems have refrigerant-specific service requirements and may require a particular compressor oil. Mixing refrigerants can contaminate the vehicle and recovery equipment, complicate diagnosis, and turn a routine repair into a much more expensive cleanup. Why the Charge Amount Matters Too Identifying the refrigerant is only the first half of the job. The charge quantity printed on the vehicle label is system-specific. “One can” is not a specification, and a low-pressure gauge by itself does not tell you how much refrigerant the system contains. A low charge often means there is a leak. Adding refrigerant without finding the leak can give only temporary cooling and may lead to an incorrect charge. Professional service equipment recovers the existing refrigerant, measures what was removed, evacuates the system, checks the repair, and recharges the specified amount by weight. If the A/C is warm, the compressor is not engaging, or the system has been opened for a repair, diagnosis should come before a refrigerant purchase. Electrical faults, airflow problems, sensor failures, compressor damage, and blend-door issues can all produce “not cooling” symptoms without a low refrigerant charge. What If the Label Is Missing, Wrong, or Shows a Retrofit? Do not identify the system from the service-port shape alone. Ports can be damaged or altered, and older vehicles may have been retrofitted. Use this order of checks: Search the engine compartment carefully for the original A/C charge label and any later retrofit label. Check the owner’s manual and factory service information for the exact VIN and equipment configuration. Look for documented A/C repairs or a retrofit invoice. If the history is unclear, have a qualified shop identify the refrigerant before recovery or charging. A proper retrofit label should identify the replacement refrigerant and charge information. If an older vehicle still has conflicting labels or improvised fittings, treat that as a warning that the refrigerant may be contaminated. Buying the Correct Automotive Refrigerant Once the vehicle label and service information agree, match the refrigerant designation exactly. FreonMarketShop carries R134a refrigerant and R1234yf refrigerant , along with other products in our automotive A/C collection . Before ordering, confirm the container size is appropriate for the job and that the purchaser and technician meet applicable requirements. In the United States, EPA sales rules distinguish small self-sealing cans intended for certain DIY motor-vehicle use from larger cylinders and other restricted refrigerant sales. A product being available online does not override those rules or the vehicle manufacturer’s service instructions. A 60-Second Refrigerant Check Read the under-hood A/C label. Write down the refrigerant designation and charge weight. Confirm the specification against factory information if the label is unclear. Do not mix R134a and R1234yf or use fitting adapters. Diagnose a leak or other fault before topping off a poorly cooling system. Match the product, equipment, oil, and service procedure to the exact vehicle. The safe buying decision is simple: trust the vehicle’s refrigerant label and exact service specification—not a model-year guess, a universal recharge kit, or the connector that happens to fit. Technical references: U.S. EPA: Unique Fittings and Label Colors ; U.S. EPA: Acceptable MVAC Refrigerants and Their Impacts ; U.S. EPA: Refrigerant Sales Restriction ; GM Service Bulletin 12-01-37-001F .