Car refrigerant & oil filling quantities

Here you will find useful information and handy tips relating to refrigerant and oil filling quantities for air-conditioning systems in vehicles.

Refrigerant and compressor oil are two essential substances for any air-conditioning system. It is also crucial to ensure the correct filling quantities. Scroll through this page and find out about the different variants of refrigerant and compressor oils. You can also find important information on refilling refrigerant and a link to the refrigerant and oil filling quantity manual.

Important safety information
The following technical information and practical tips have been compiled by HELLA in order to provide professional support to vehicle workshops in their day-to-day work. The information provided on this website is intended for use by suitably qualified personnel only.



There are still numerous vehicles on the market with air-conditioning systems originally designed for refrigerant R12. 2001 marked the official final end of R12 in vehicle air-conditioning systems. Ever since then, R12 systems had to be converted during maintenance or repair work. R134a was and is used as replacement refrigerant besides several "drop-in" refrigerants (refrigerant mixtures).


Even today, the conversion from R12 to R134a is still an ongoing topic in the area of classic and modern classic cars as well as in several non-EU countries.


In the course of conversion, the system must be checked for leak tightness. Leaks must be corrected beforehand. All components should be checked for function and damage. The filter dryer is to be replaced. Sealing rings should be replaced. In addition, the mineral oil of the R12 system is to be replaced with PAG or PAO oil. In the course of this replacement it is also recommended to flush the air-conditioning system.


R134a has a high GWP (global warming potential) of 1430. With the current EC Directive 2006/40/EC it was decided to only use refrigerants with a GWP of less than 150 in the future.


Air-conditioning systems in vehicles of class M1 (passenger cars, vehicles with up to 8 passenger seats) and class N1 (commercial vehicles with a permissible total weight of up to 3.5 metric tons) for which a type approval was issued within the EU as of January 1, 2011, can therefore no longer be filled with R134a. As of January 1, 2017, vehicles filled with R134a are no longer entitled to receive initial registration approval. R134a can, however, continue to be used to carry out service and maintenance work on existing R134a systems. R1234yf with a GWP of 4 shall be used as new refrigerant. Other refrigerants can also be used, however, provided their GWP value is below 150. Only in time will it become apparent if all vehicle manufacturers agree on a single refrigerant, or whether different refrigerants will be used.


This, of course, also impacts workshops and their service personnel. As such, it appears that purchasing new service units is something that cannot be avoided. Separate measures with respect to storing and handling the new refrigerants must certainly also be observed.


When refilling refrigerant and performing any work on the refrigerant circuit, please observe the following:

  • Always wear protective goggles and gloves! Under normal atmospheric pressure and ambient temperatures, liquid refrigerant evaporates so quickly that any physical contact with the skin or eyes can cause the tissue to freeze (risk of blindness).
  • If direct physical contact has been made, thoroughly rinse the affected areas with a generous supply of cold water. Do not rub. Seek the medical attention of a doctor immediately!
  • The workplace must be well ventilated for working on refrigerant circuits. Breathing in high concentrations of gaseous refrigerant can cause dizziness and even suffocation. Do not work on the refrigerant circuit from an inspection pit. As gaseous refrigerant is heavier than air, it can collect in high concentrations there.
  • Do not smoke! Refrigerant can be broken down into poisonous substances if it contacts cigarette ash.
  • Do not introduce an open flame or hot metal in the immediate vicinity of refrigerant. Doing so can cause lethal gases to form.
  • Never allow refrigerant to leak out into the atmosphere. If the refrigerant reservoir or air-conditioning system is opened, its contents will escape under high pressure. The extent of the pressure depends on the temperature. The higher the temperature, the higher the pressure.
  • Do not expose any components of the air-conditioning system to heat. After paintwork, do not heat vehicles above 75°C (drying furnace). If this cannot be avoided, drain the air-conditioning system beforehand.
  • When removing the service tubes from the vehicle, do not point the connections toward your body. Refrigerant residues may leak.
  • When cleaning the vehicle, do not point the steam-jet cleaner directly onto parts of the air-conditioning system.
  • Never change the factory setting of the adjusting screw on the expansion valve.


Which filling quantities apply to which vehicles? Our latest manual for refrigerant and oil filling quantities provides the answer for the most common vehicle types.

1 Condenser with round pipes
2 Condenser with flat pipes
3 Condenser 16 mm
4 Condenser 23 mm
5 Rear engine
6 Front engine
7 Expansion valve, old type
8 Expansion valve, new type
9 See sticker in engine compartment
n.a. Overall quantity for system not known or not specified by manufacturer – if appropriate, see sticker in the engine compartment or on the compressor
q Quantity depends on version – see sticker in the engine compartment or on the compressor
w Condenser 18 mm
e Condenser 20 mm
f Thickness of the condenser’s flat pipe
g Without oil radiator
h Condenser module, dryer integrated in the condenser
i Orga/manuf. no. /see information near A/B pillar
VIN = Vehicle Identification Number

Notes Commercial Vehicles

(1) OE Hella
Compressor Unicla: PAG OIL UNIDAP PAO 68 of PAG ISO 46
Compressor Zexel: PAG OIL ZEXEL ZXL 100PG PAO 68 of PAG ISO 46
Compressor Sanden: PAG OIL SANDEN SP 20 PAO 68 of PAG ISO 100
Compressor Nippondenso: PAG OIL ND 8 PAO 68 of PAG ISO 46
Compressor Kiki: FUCHS RENISO PAG 46” PAO 68 of PAG ISO 46
Oil filling quantity ʼn .a.” = quantity unknown or not specified by the manufacturer

Refrigerant analysis using the Inspector

Check of the air-conditioning system for impurities using the Inspector.


03:34 min