The correct refrigerant for a car’s air conditioning is the type specified by the vehicle manufacturer. Check the A/C label or the vehicle manual before buying refrigerant or booking a recharge. R134a, R1234yf, R152a and R744 have different properties and are not interchangeable. The car’s year of manufacture alone does not identify the right gas.
How to identify your car’s A/C refrigerant
The A/C label, usually in the engine compartment, identifies the refrigerant and the specified charge mass. Look for the full designation, such as R134a or R1234yf. If the label is missing or unreadable, have a qualified workshop confirm the specification from the manufacturer’s service information.
Use that specification when arranging service. A cheaper product, a lower GWP or a recommendation for a different car does not establish compatibility with your system.
R134a, R1234yf, R152a and R744: key differences
| Refrigerant | Type | Safety class | Use in vehicle A/C |
|---|---|---|---|
| R134a | Synthetic HFC | A1 | For systems specified for R134a. It has a high global warming potential. |
| R1234yf | Synthetic HFO | A2L | For systems specified for R1234yf. It has a much lower GWP than R134a. |
| R152a | Synthetic HFC | A2 | Flammable; it is not a routine recharge alternative for an R134a or R1234yf system. |
| R744 (CO₂) | Carbon dioxide, a natural refrigerant | A1 | For dedicated CO₂ systems with components and service equipment rated for their high operating pressures. |
In the ASHRAE classification, A indicates lower toxicity. A1 means no flame propagation under the standard’s test conditions; A2L denotes lower flammability with a low burning velocity; A2 denotes flammability. These classes do not specify operating pressure or mean that handling is risk-free.
Why R152a and CO₂ need separate explanations
R152a: a synthetic, flammable HFC
R152a is 1,1-difluoroethane, a synthetic fluorinated refrigerant. It is not a natural refrigerant and its A2 classification differs from R1234yf’s A2L classification. Its lower GWP compared with R134a does not make it suitable for filling an existing car A/C system. Use would require a system specifically approved for it; an ordinary recharge is not a conversion procedure.
R744: CO₂ in a purpose-designed high-pressure system
R744 is carbon dioxide. Automotive CO₂ circuits operate at substantially higher pressures than R134a and R1234yf circuits and require dedicated components and servicing equipment. R744 is already used in production vehicles, including some electric vehicles. Its A1 classification does not remove the risks associated with high pressure or excessive CO₂ concentrations.
Does the year of manufacture determine the refrigerant?
No. Under the EU MAC Directive 2006/40/EC, from 1 January 2017 new vehicles within its scope—passenger cars in category M1 and light commercial vehicles in category N1, class I—cannot be placed on the EU market with A/C systems using fluorinated gases with a GWP above 150. The directive does not require R1234yf specifically.
This rule does not require every existing R134a vehicle to be converted. Treat the year as background information and use the vehicle’s refrigerant specification for servicing. It is also incorrect to assume that every electric car uses R744.
What low GWP tells you about a refrigerant
GWP describes a gas’s contribution to global warming relative to CO₂. A lower GWP means a smaller direct warming effect for the same mass released. It does not establish complete environmental safety or compatibility with a particular vehicle.
Cooling performance also depends on system design, component condition and the correct refrigerant charge. There is no sound basis for telling every driver that R1234yf will cool less effectively than R134a. Changing gas is not a remedy for an undiagnosed cooling fault.
What matters when servicing and ordering refrigerant
- Use the specified gas. Do not mix different refrigerants or substitute one during a recharge.
- Check the cause of poor cooling. A workshop should diagnose the fault and address any leaks, rather than repeatedly top up the system.
- Follow the specified charge mass and oil requirements. Use a qualified workshop with equipment suitable for the refrigerant.
If you are sourcing refrigerant for a workshop, consult the R-134a and R-1234yf product pages. Match the product to the vehicle’s specified gas before ordering.
Related reading
Read more about the environmental benefits of low-GWP refrigerants for your business and what the GWP indicator means when comparing products.
For stationary air conditioning, see our guide to the advantages and disadvantages of different types of refrigerants for air conditioners. That comparison concerns building systems; it is not a list of replacement gases for a car’s A/C.
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