Car Refrigerant Oil Guide 2024


A car is made from several different mechanisms that are working simultaneously to help it run efficiently. One such mechanism is the cooling mechanism, in which the air-conditioning system requires a special type of oil. This oil is known as the car refrigerant oil.

Although you can find several companies that make these oils, Automobile Remedy offers a premium quality oil that improves the car’s cooling system’s efficiency.

To select the best oil for a car refrigerant system, it is better to understand why it is needed in the first place. For this, it is necessary to know how the refrigerant system works. The refrigerant system is a mechanical process where the compressor compresses the air, making it cool by reducing the molecules’ kinetic energy and supplying cool air inside the car.


This system consists of a piston that produces a vacuum or low pressure to take the hot air, compresses the hot air to remove the air’s kinetic energy, and produces cold air. In most of the latest cars, the refrigerant agent is upgraded from R-12 to R-134a. As discussed above, the compression takes place to produce cold air, but this process also produces a lot of heat, a by-product of the whole process.

You can see the compressor on the top of the engine where it is connected to the engine with the help of a belt: this best also helps in the compressor’s rotation. Since compression is a mechanical process, moving parts cause wear and tear within the compressor. Heat is also produced as there is a lot of fluctuation in the temperature. Therefore, if proper lubrication is not done, the parts will fail, and the system will collapse.

In the absence of lubrication, or if the lubrication is not done properly, the whole compressor will deteriorate and will have to be replaced. If proper lubrication is not done, the seals in the compressor or condenser may get damaged, and the refrigerant agent will be leaked sooner or later. This will affect the cooling system of the car, and eventually, the refrigerant, along with oil, will completely come out of the car’s cooling system.

That is why it is essential to take care of the cooling system and use the best oil for the car’s refrigerant system. Whenever there is a need for the refrigerant agent, it must be added to the car’s cooling system. It is important for the cooling process and acts as a sealant for the rubbers present in the compressor.

There are many kinds of oils available in the market with different qualities and features. It is important to mention some of the features you should keep in mind before adding it to the car’s cooling system. There are oils with different viscosity and characteristics. So, you cant use every oil in every cooling system of the car. Quality and compatibility are not the only factors that need to be taken care of. While taking care of the cooling system of the car, its quantity is also equally important.


Every compressor has its own built and requirement of the oil; most of the time, the cooling system’s refrigerant agent decides which oil to be used. Some of the commonly used types are discussed below:

Polyalkylene glycol

It is also known as PAG, and it is mostly used in the latest refrigerant cooling systems that use R-134 and R-1234yf cooling agents. It is an artificial lubricant that comes in different viscosities and is classified as PAG150, PAG100, and PAG46.

However, it has a serious drawback i.e., it gets to mix with the moisture present in the air-cooling system. As a result, it produces acid, and this acid has corrosive properties that damage different parts of the cooling system. So, you should avoid this type of oil in the refrigerant line junctions or compressor shafts and O-rings. Most importantly, you shouldn’t use it in hybrid cars as it is electrically conductive.


It is commonly known as Alkyl Benzene oil, and it is mostly used in the cooling system that uses an R-12 refrigerant agent. Opposite to the PAG, it does not absorb moisture that is the main reason it is used as a lubricant in the seals and O-ring in both R-134a and R-12 refrigerant systems.

Polyester, Ester

It is also known as POE oil, but any manufacturer does not recommend it as because of the following reasons:

  • Under-performance in high heat, load situations
  • Moisture absorption

Furthermore, it works best in hybrid cars with a compressor that uses electrical power as it has the best insulating characteristics.


It is commonly known as PAO which is a synthetic and multi-grade oil. It is used in various cooling systems and majorly as an alternative to PAG if recommended by the compressor manufacturer.

Using the right type of oil increases the compressor’s life, but at the same time, the right quantity of the oil is also significant for the life and performance of the compressor. You can check its quantity by the process known as oil balancing, where less amount of the oil in the cooling system will starve the system of the lubrication and causing wear and tear effects on the compressor and other parts of the cooling system.


However, if its quantity is increased, it will affect the cooling of the system. It is better to check the quantity of the oil from the failed compressor to measure drained oil. The quantity measured from the old compressor is added to the new compressor, but it is also important to check and follow the compressor manufacturer’s instructions.

Nowadays, most the compressor manufacturer is offering compressors with the right quantity of oil-filled by default. This solves many problems, but it is important to know about other parts of the cooling system in detail to get the best oil in the right quantity.