One of the most common questions in vehicle AC servicing is: does this car use R134a or R1234yf? Getting it wrong — even accidentally — can damage the AC system, void the warranty, and breach UK F-Gas regulations. This guide explains exactly how to identify the correct refrigerant for any UK vehicle.
The Short Answer: Check the Data Plate
Every vehicle with a factory-fitted AC system has a refrigerant data plate, typically a sticker located under the bonnet (engine bay). This plate states:
- The refrigerant type (e.g. HFC-134a or HFO-1234yf)
- The correct charge weight in grams
- Sometimes the compressor oil type and charge weight
Always use the refrigerant specified on the data plate. Never assume based on the vehicle age alone — some models transitioned to R1234yf before the 2017 deadline, and some have exceptions.
The History: How We Got from R12 to R1234yf
Vehicle AC refrigerants have gone through three generations in the UK:
R12 (pre-1995) — Now Banned
R12 (dichlorodifluoromethane, a CFC) was the original automotive AC refrigerant. It was phased out across Europe from the mid-1990s due to its severe ozone depletion potential (ODP 1.0). R12 is now banned and unavailable for new purchases. Any R12 system still in service requires recovery of the remaining charge by a certified engineer and retrofit to an approved alternative.
R134a (1995 – December 2016) — Still in Service
R134a (tetrafluoroethane, HFC-134a) replaced R12 as the standard automotive AC refrigerant from the mid-1990s. It has zero ozone depletion potential (ODP 0) but a significant GWP of 1,430. The vast majority of UK vehicles manufactured between approximately 1995 and December 2016 use R134a.
R134a remains legal for servicing existing systems. Refrigerant Gas Supplies Ltd stocks R134a in 13.6 kg cylinders for F-Gas Category II certified engineers.
R1234yf (January 2017 onwards) — Current Standard
From 1 January 2017, the EU MAC Directive (2006/40/EC) required all new passenger vehicles to use a refrigerant with a GWP below 150. R1234yf (2,3,3,3-tetrafluoropropene, HFO-1234yf) became the industry-standard replacement, with a GWP of just 4 — 99.7% lower than R134a.
All new passenger cars sold in the UK from January 2017 use R1234yf. Many manufacturers transitioned earlier: Daimler/Mercedes switched from 2013, and several other OEMs followed from 2014–2016. R1234yf is available from Refrigerant Gas Supplies Ltd in 5 kg cylinders.
Why You Cannot Mix R134a and R1234yf
R134a and R1234yf are not compatible and must never be mixed or cross-charged. Key reasons:
- Different valve fittings: R1234yf service ports use a dedicated SAE J2888 fitting that physically prevents connecting R134a charging equipment. This is by design to prevent accidental cross-contamination.
- Different pressures: R1234yf operates at slightly different pressures to R134a, meaning a system designed for one will not perform correctly charged with the other.
- Legal requirement: Using the wrong refrigerant violates UK F-Gas regulations. Engineers found charging R1234yf systems with R134a (or vice versa) risk prosecution and loss of F-Gas certification.
- Warranty: Using the incorrect refrigerant voids the vehicle warranty and AC system warranty.
Quick Reference Guide: Which Refrigerant for Your Vehicle?
| Vehicle manufacture date | Likely refrigerant | Action |
|---|---|---|
| Before ~1995 | R12 (banned CFC) | Must be recovered; retrofit required |
| ~1995 to Dec 2016 | R134a | Confirm on data plate; use R134a |
| Jan 2017 onwards | R1234yf | Confirm on data plate; use R1234yf |
| 2013–2016 (some models) | R1234yf (early adopter) | Always check data plate for certainty |
Buying Automotive Refrigerants in the UK
Refrigerant Gas Supplies Ltd, based in Wakefield, Yorkshire, supplies both automotive refrigerants to F-Gas Category II certified engineers and garages across the UK:
- R134a 13.6 kg cylinder — for pre-2017 vehicles. 99.9% purity. A1 safety. GWP 1,430.
- R1234yf 5 kg cylinder — for 2017+ vehicles. Ultra-low GWP 4. A2L (mildly flammable).
Next-day mainland UK delivery. F-Gas Category II certification required. Call +44 7988 028925 for trade pricing. Browse our full refrigerant gas range.
Frequently Asked Questions
How do I know if my car uses R134a or R1234yf?
Check the refrigerant data plate under the bonnet — it states the refrigerant type and correct charge weight. As a general rule: pre-2017 vehicles use R134a; 2017+ vehicles use R1234yf. Always confirm on the data plate before charging.
Can I use R134a instead of R1234yf in my car?
No. They use different valve fittings, have different properties, and are not interchangeable. Using the wrong refrigerant is illegal under UK F-Gas regulations, can damage the AC system, and voids the vehicle warranty.
Why did car manufacturers switch from R134a to R1234yf?
EU/UK regulations (MAC Directive 2006/40/EC) required refrigerants with GWP below 150 in new vehicles from January 2017. R1234yf (GWP 4) replaced R134a (GWP 1,430) as the standard vehicle AC refrigerant — a 99.7% reduction in global warming potential.
Where can I buy R134a or R1234yf refrigerant in the UK?
Refrigerant Gas Supplies Ltd supplies R134a (13.6 kg) and R1234yf (5 kg) to F-Gas Category II certified engineers across the UK, with next-day mainland delivery. Call +44 7988 028925 or visit our refrigerant gas range.