R134a vs R1234yf: how to tell which refrigerant your car uses

The refrigerant carries the heat out of the car. It circulates in a closed system and keeps changing between liquid and gas. In the evaporator behind the dashboard it absorbs heat from the air inside the car. The compressor brings the gas up to high pressure. In the condenser at the front of the car it releases that heat into the outside air.

The refrigerant also carries oil. That oil lubricates the compressor. So a system is built for one refrigerant and one type of oil, with its own connections and seals.

Cars in the Netherlands mainly use R134a and R1234yf. Which one your car uses depends on the make, the model and the production date. The switch from R134a to R1234yf comes from the European directive on air conditioning in motor vehicles (2006/40/EC). It requires new cars to use a refrigerant that contributes little to global warming.

R134a was the standard refrigerant in car air con systems for decades, and most cars up to about 2017 still use it. Its chemical name is tetrafluoroethane.

R134a has a GWP of 1,430. That is the value in the European F-gas Regulation (EU) 2024/573, as shown in the GWP table of the German Environment Agency (Umweltbundesamt). HELLA gives the same figure. GWP stands for global warming potential: the warming effect compared with CO2. So one kilo of R134a released into the air warms the planet about as much as 1,430 kilos of CO2. That is why R134a is no longer allowed in the air con of new cars.

Do you drive a car with R134a? Then you may keep servicing it with R134a. According to HELLA, R134a may still be used to service existing R134a systems. We do that too. Use the refrigerant the manufacturer specifies for your car.

R1234yf is the refrigerant that replaced R134a in new cars. Its chemical name is 2,3,3,3-tetrafluoropropene. The F-gas Regulation (EU) 2024/573 gives R1234yf a GWP of 0.501, so less than 1. An older calculation, which HELLA still uses, gives 4. The difference comes from the calculation method. Either way it contributes far less to global warming than R134a.

European Directive 2006/40/EC works in two steps:

According to the Umweltbundesamt, R1234yf has been on the European market for new cars since 2012. A model approved before 2011 could still be sold with R134a until 2017. That is why a car from 2011 to 2016 can have either refrigerant.

R1234yf is mildly flammable (safety class A2L). The system in the car is designed for this. A garage does have to recover, store and fill it with suitable equipment and according to the safety rules. Below you can read whether R1234yf is toxic or dangerous.

The biggest difference is the warming effect. The price, the flammability and the service connections differ too.

Sources: Directive 2006/40/EC, F-gas Regulation (EU) 2024/573 via the GWP table of the Umweltbundesamt, HELLA and Umweltbundesamt. Our prices are prices from, including recovering the refrigerant, vacuuming, the leak tightness check, refilling to the factory amount and VAT.

For you as a driver, R1234yf is not dangerous in normal use of the car. The refrigerant is inside a closed system. R1234yf falls into safety class A2L. The A stands for low toxicity, the 2L for mildly flammable.

Its flammability was debated for years. The research centre of the European Commission (JRC) concluded in March 2014 that the tests with cars gave no evidence of a serious risk. According to the same JRC report, the auto-ignition temperature of R1234yf is 405 °C.

You may have read about a PFAS ban and R1234yf. The European Union is looking at a restriction on PFAS, which could also cover R1234yf. No decision has been made yet. R1234yf is allowed, in new and in existing cars. Read more in is R1234yf being banned?

The quickest and most reliable way is the sticker under the bonnet. There are three ways:

1. Look at the sticker under the bonnet. Open the bonnet and look for an air con sticker. It is often on the underside of the bonnet, near the bonnet catch or near the radiator. According to HELLA it is sometimes on the compressor. The sticker says “R-134a” or “R-1234yf”, often with the fill quantity in grams and the type of oil. That quantity differs from car to car.
2. Use the year only as a first clue. Most cars up to about 2017 use R134a, most cars from 2017 use R1234yf. For cars from 2011 to 2016 the year does not give certainty.
3. Have it looked up with your registration number. A garage can look up the refrigerant and the fill quantity with the registration number or the chassis number (VIN). The Dutch registration certificate (kentekenbewijs) does not show the refrigerant.

What is on the sticker? Usually three things. The refrigerant, for example R-1234yf. The fill quantity in grams, with a small tolerance. And the type of compressor oil, often marked PAG or POE. That oil matters. An electric compressor in a hybrid or electric car needs oil that does not conduct electricity. If the wrong oil gets in, the insulation of the compressor can deteriorate. That is why at every air con service we check not only the refrigerant, but also the oil the manufacturer specifies.

Is the sticker missing or unreadable, for example after a repair to the front of the car? Then we look up the data with the registration number. We do not fill by guesswork: the air con service machine weighs out the specified amount. How many grams cars usually need, you can read in how much refrigerant is in your car air con.

Still not sure? Call +31 10 479 00 00 with your registration number. We look it up for you and we tell you straight away what an air con service costs for your car. We work by appointment. For a quick question or check you can walk in without an appointment.

An air con service with R1234yf costs more mainly because of the refrigerant itself: R1234yf costs more per kilo than R134a. The workshop equipment is also different, because R1234yf is mildly flammable and has its own connections. The work itself is largely the same.

With us an air con service costs from € 120 for a car with R134a and from € 180 for a car with R1234yf. That includes recovering the refrigerant, vacuuming, the leak tightness check, refilling to the factory amount and VAT. The price for your car depends on how much refrigerant the system needs. We tell you in advance. You can read more about what happens during the service on our page about a car air con regas in Rotterdam.

Do you drive a hybrid or electric car? Then we tell you the price in advance when you call with your registration number. Our technicians hold the GMTO certificate (the Dutch qualification for working on high-voltage systems). If we find a leak or another fault during the check, you get a quote first. We only carry out repairs once you have agreed. You can read what air con repairs cost in our article car air con repair cost in the Netherlands.

A small number of newer cars use R744 as refrigerant. That is CO2, with a GWP of 1. According to the Umweltbundesamt, the first cars with CO2 as refrigerant came onto the market in 2016. An R744 system works at much higher pressures and needs its own equipment. You find it in some electric cars with a heat pump, among others.

No. That is not allowed. Under the European F-gas Regulation (EU) 2024/573 only someone with a certificate or training attestation may work on a car air con. Only businesses with such technicians may buy R134a and R1234yf, and disposable cans of refrigerant are banned. According to the Dutch government information point IPLO (Informatiepunt Leefomgeving), since 7 October 2026 anyone without a certificate needs a training attestation to work on a vehicle air con or to buy refrigerant. Existing certificates remain valid until 12 March 2029. Read more in can you recharge your car air con yourself?

With a DIY recharge kit you also do not know how much refrigerant is still in the system. Too much refrigerant is bad for the compressor. And if the air con is losing refrigerant, there is a leak. Then refilling only helps for a short time. Under Directive 2006/40/EC a garage only refills a system with an abnormal leak once the repair is done.

We hold an F-gas certificate for car air con systems with R134a and R1234yf. During an air con service we first recover all the refrigerant and check with a vacuum test whether the system is sealed. Only then do we refill it to the factory amount. If the system does not hold the vacuum, we do not refill and we look for the leak first. Does the air con not cool at all any more? Then also read car air con not working. Everything about the air con service is on our page about car air conditioning in Rotterdam.

Since 1 January 2017 the air con of every newly registered passenger car in the European Union must use a refrigerant with a GWP below 150. For new car types that applied from 2011, and R1234yf has been on the market since 2012. So a car from 2011 to 2016 can have either. Check the sticker under the bonnet.

At Autobedrijf Willemsbrug an air con service costs from € 120 with R134a and from € 180 with R1234yf, including recovering the refrigerant, vacuuming, the leak tightness check, refilling to the factory amount and VAT. The price for your car depends on how much refrigerant it needs. We tell you in advance.

No. We advise against it. A system is built for one refrigerant, with its own connections, oil and parts, and a car built for R134a is not designed for a mildly flammable refrigerant. You may keep servicing an older car with R134a.

Yes. The ban applies to new cars, not to cars that are already on the road. A car with R134a may be refilled with R134a during an air con service. This must be done by a certified technician.

No. Converting to R134a has not been allowed for passenger cars and light vans since 1 January 2017. European Directive 2006/40/EC only allows refilling a system that already contained R134a. R12 itself damages the ozone layer and may no longer be used in the European Union. Call us with your registration number and we will discuss what is possible for your car.

The air con then cools less well and the compressor can be damaged. The system is contaminated and has to be recovered, cleaned and refilled, sometimes with repairs. That is why we look up which refrigerant and which amount are specified for your car before we start.

Yes. R1234yf is mildly flammable (safety class A2L). The car and the workshop equipment are designed for this. Research by the European Commission found no evidence of a serious risk in cars in 2014. For you as a driver nothing changes.

Yes. Many electric cars use R1234yf, because the European rule of a GWP below 150 applies to them too. Some electric cars with a heat pump use R744 (CO2). Check the sticker under the bonnet or call us with your registration number.

• EUR-Lex: Directive 2006/40/EC relating to emissions from air-conditioning systems in motor vehicles (Articles 5 and 6)
• HELLA: Car refrigerant & oil filling quantities
• Umweltbundesamt: Global Warming Potentials (GWP) of selected compounds and their mixtures (IPCC AR4, AR5 and Regulation (EU) 2024/573)
• Umweltbundesamt: Mobile air conditioning in cars, buses and railway vehicles
• Informatiepunt Leefomgeving (IPLO): Nieuwe F-gassenregels: overgang van certificaten naar opleidingsattesten voor voertuig-airco’s (in Dutch)
• European Commission (JRC): JRC technical and scientific support to the research on safety aspects of the use of refrigerant R1234yf on MAC systems (3 March 2014)