Compressor oil and refrigerant: Mixing old and new

With the new R1234yf refrigerant reaching Europe this year, DENSO’s A/C experts explain which mixtures will work, and how to avoid causing costly damage by using incorrect oils.

Compressor Cutaway

All vehicles manufactured from 1 January 2017 will operate using an A/C system filled with the new R1234yf refrigerant.

This means vehicles built before January 2017 designed to use R134a refrigerant systems will need a manufacturing upgrade of the vehicle A/C system for the R1234yf type refrigerant to comply with new EU regulations.

The update also brings with it a new type of compressor oil for workshops and suppliers to be aware of.

In with the new

DENSO uses ND-oil 8 for its R134a type refrigerant compressors, a PAG 46 oil. The new refrigerant type uses ND-oil 12, also a PAG 46 oil but with additives specifically for the R1234yf type refrigerant.

However, this doesn’t mean the two oils are interchangeable; while ND-oil 12 can be used for both R134a and R1234yf, it doesn’t work the other way around and ND-oil 8 cannot be used for R1234yf type refrigerant.

It can get confusing with the number of different compressors, each with a specific DENSO oil. To clear this up, below is an overview of different types of DENSO oils for R134a and R1234yf type refrigerants which are available to the Aftermarket.

Compressor Oil (1)

Mixing oils

While mixing A/C Compressor oils is usually not recommended, as it can lead to A/C Compressor damage and failure, the new ND-oil 12 can be used with both R1234yf and the old R134a type refrigerants.

However, once A/C systems have been upgraded to R1234yf type refrigerants, A/C Compressors pre-filled with ND-oil 8 can no longer be used in the system. When R1234yf type refrigerant comes in to contact with ND-oil 8, it will decompose and resin parts of the A/C system will start to deteriorate, so it is never recommended to use ND-oil 8 in combination with R1234yf type refrigerant.

The new ND-oil 12 can be used in R134a type refrigerant systems, without needing to flush the system and remove the remaining ND-oil 8 from the A/C system, though technicians must make sure there is no dirt in the A/C system.


The impact on the Aftermarket

The first changes in the Aftermarket have appeared for FIAT applications. DENSO supplied the DCP09003, which was used for several models with R134a type refrigerant A/C systems, and pre-filled with ND-oil 8. The DCP09003 has been replaced with the DCP09060, the new part is used for the same FIAT models, but which are now equipped with R1234yf type refrigerant A/C systems and pre-filled with ND-oil 12.

With the demands of the market shifting all the time, and automotive manufacturers updating their products and models, DENSO is developing new ND-Oil 12 part numbers to provide the most advanced service on the market.

Owning a 40% share in the European OE Compressor market, DENSO is one of the industry’s leading manufacturers bringing its expertise to the aftermarket.

Find out more

Further details of DENSO’s product range are available online at, on TecDoc or from your local DENSO Aftermarket sales contact.