R134a vs R1234yf: Which Refrigerant Does My Car Use?
Short answer
Cars first registered before around 2015 use R134a refrigerant; cars from roughly 2017 onwards use R1234yf, with a mixed changeover between 2015 and 2017. The correct gas is printed on a label under the bonnet, and the two must never be mixed.
Key takeaways
- Pre-2015 cars: R134a. Post-2017 cars: R1234yf. 2015–2017 varies by model.
- Check the sticker under the bonnet — it states the gas type and charge weight.
- R1234yf is far more expensive, which is why re-gas prices differ between cars.
- The £229 condenser fitting price includes a full recharge with either gas.
There are two car air conditioning refrigerants in everyday UK use: R134a and R1234yf. They do the same job, but they are chemically different, they are charged at different pressures, and they must never be mixed. Knowing which one your car takes matters both for a re-gas and for a condenser replacement.
R134a: the older standard
R134a was the standard automotive refrigerant from the mid-1990s until the changeover. If your car was registered before roughly 2015, it almost certainly uses R134a. It is inexpensive, widely available and well understood.
R1234yf: the current standard
R1234yf was introduced to meet EU rules on greenhouse gases, which required new car types from 2011 and all new cars from 2017 to move to a low global-warming refrigerant. In practice, most cars registered from around 2017 onwards use R1234yf. It is significantly more expensive than R134a, and it is mildly flammable, so it requires dedicated equipment and handling.
How to check which your car uses
- Under-bonnet label. Almost every car carries a sticker on the slam panel, strut tower or underside of the bonnet stating the refrigerant type and charge weight in grams.
- Registration year. Pre-2015 is usually R134a; 2017 onwards is usually R1234yf. Between those years it can be either, so check the label.
- Service port fittings. R1234yf systems use different quick-connect couplings so the wrong gas cannot easily be charged in.
- Handbook or VIN lookup. The owner's manual and a VIN-based parts lookup will both confirm the specification.
Why they must never be mixed
Mixing refrigerants contaminates the gas so it cannot be recovered and recycled, upsets system pressures, and can damage the compressor. It also renders any future diagnosis unreliable, because pressure readings no longer mean what they should. Contaminated systems generally have to be flushed and recharged from scratch, which costs far more than getting it right first time.
Does gas type change the condenser?
The condenser itself is specified by vehicle, not by gas. What changes is the charge procedure and the cost of the refrigerant. R1234yf systems also tend to be less tolerant of contamination and moisture, so a correct vacuum before charging matters even more.
What we do
Our fixed £229 condenser fitting price includes a full re-gas with the correct refrigerant for your car, whether that is R134a or R1234yf, plus new O-rings and seals, a vacuum and a leak test. There is no surcharge for R1234yf vehicles.
See the condenser fitting service and pricing, or book a slot online with Darren.
Frequently asked questions
How do I know if my car uses R134a or R1234yf?
Look for the air conditioning label under the bonnet, usually on the slam panel or strut tower. It names the refrigerant and the charge weight in grams. As a rule of thumb, pre-2015 cars use R134a and post-2017 cars use R1234yf.
Can you put R134a in an R1234yf car?
No. The gases have different pressures, oils and service fittings, and mixing them contaminates the system and the recovery equipment. It also invalidates any warranty on the work.
Why is an R1234yf re-gas more expensive?
R1234yf costs several times more per kilogram than R134a and needs separate handling equipment, so the refrigerant itself is the bulk of the price difference.