Can I mix 1234yf with 134a?

Author: Ara Swaniawski PhD  |  Last update: Tuesday, April 21, 2026

Refrigerant types are not to be mixed. The usage of dyes and sealants is discouraged. Dyes and sealants are considered contaminants and will reduce the performance and longevity of the lubricant. Use refrigerant sniffers for leak detection and repair leaking equipment per SAE and EPA guidelines.

Can I mix R134a and R1234yf?

The two different gasses should not be mixed. You cannot fit the 1234yf connectors on a 134A system anyway as they are different sizes.

Is R1234yf oil compatible with R134a?

HFO-1234yf (R-1234yf ) has a global warming impact value of 1 versus 1300 for R-134a. It breaks down chemically in the atmosphere in only 11 days versus 13 years for R-134a! While R-1234yf oils are backwards compatible with R-134a systems, R-134a PAG oils are not compatible with R-1234yf systems.

Is R1234yf a drop in for R134a?

The above research indicates that R1234yf can be used as a drop-in replacement for R134a, meaning that automotive manufacturers do not need significant modifications. Currently, the main issue with R1234yf is its mild flammability.

Are R134a and R1234yf fittings the same?

R-134a and R-1234yf systems have unique fittings so they can only be used with the appropriate corresponding refrigerants and equipment. R-1234yf is very expensive. This has led to end-users trying to replace the refrigerant in vehicles originally containing R-1234yf with R-134a, in an attempt to save money.

Converting R1234YF to R134A... was it a mistake?

Is it illegal to put 134a in a 1234yf system?

Still, the answer is an emphatic, “No.” Not only would a retrofit of this type negate the environmental benefits of R-1234yf, but it would also be a violation of Federal Law under Section 203 of the Clean Air Act: “tampering” with a vehicle's emissions control device.

Is R1234yf a direct replacement for R134a?

There are three refrigerants that can be used to replace R-134a: R-1234yf, R-152a, and R-744.

Does R134a cool better than R1234yf?

However when the condensing temperature gets lower, R1234yf outperformed R134a. Over the range of operational conditions tested, the maximum difference in terms of cooling capacity is less than 5% and the COP is less than 10%.

Is R134a being phased out?

The commonly used synthetic refrigerants such as R134a, R407C and R410A have a GWP value higher than 2,500. As a result, their production is being phased out.

What are the disadvantages of R1234yf refrigerant?

Cons of R1234YF and the New Equipment
  • Higher Cost: One of the major drawbacks of R1234YF is its higher price. ...
  • Complex Maintenance: Alongside the increased cost, R1234YF also requires more complex maintenance compared to its predecessor. ...
  • Mild Flammability: Another concern with R1234YF is its mild flammability.

Why is 1234yf freon so expensive?

Switching to R1234yf refrigerant is a step towards a greener future, but it comes with higher costs due to advanced equipment, stringent regulations, and specialized training.

How can you tell the difference between R134a and R1234yf?

Most vehicles have a label or sticker under the hood that indicate whether the refrigerant used is R-134a or R-1234yf.

Can you use pag 46 in a 1234yf system?

In with the new

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

Can you mix two different types of freon?

In short, the answer is, "No!" Automotive refrigerants are volatile compounds that can have a negative effect on the environment. Combining them can have adverse effects, and cause damage to your car's A/C system.

Can you flush a R1234yf system?

The ACX universal flushing unit is designed for refrigerants R134a and R1234yf. A proper flush of the air conditioning system is one of the most important tasks to be carried out during repairs and after the replacement of a compressor.

Can I put R-1234yf in a R-134a system?

Refrigerant types are not to be mixed. The usage of dyes and sealants is discouraged. Dyes and sealants are considered contaminants and will reduce the performance and longevity of the lubricant. Use refrigerant sniffers for leak detection and repair leaking equipment per SAE and EPA guidelines.

Is R-1234yf being discontinued?

It is anticipated that by 2025 all vehicles will contain 1234YF. Don't fret, however, if your current vehicle requires 134a. Though 134a is not compatible with 1234YF and is expected to be phased out, it is still in production and will continue as long as there is a demand for repair of older vehicles.

What year did cars stop using R-134a?

R134a has been found to have a lot of greenhouse gas potential, as it can end up in the atmosphere and take forever to break down. For that reason, all new vehicles sold in America after the year 2021 can no longer use this type of refrigerant.

What is a good replacement for R134a?

R-1234yf refrigerant. To date, most auto manufacturers are using the hydro fluoro olefin (HFO) refrigerant R-1234yf as the replacement of choice for R134a.

How many cans of R134a do I need?

Most cars hold between 28 and 32 ounces of refrigerant (or about 2—3 12oz cans), however larger vehicles and those with rear A/C will likely hold more. Check your vehicle manual for the system capacity for your specific vehicle.

What is the drop-in replacement for 1234yf?

Solstice® yf (R-1234yf) refrigerant is a near drop-in replacement for R-134a in automobile A/C applications, helping automakers around the world comply with EU low GWP requirements.

What gas can replace R134a?

Possible alternatives to R-134a

Attention is increasingly focused on low-GWP refrigerants that are hydrofluoroolefins (HFO). R-1234yf in particular is often seen as a possible alternative to R-134a. The GWP value of R-1234yf is 4, which means it has a very low global warming potential.

Why is R-1234yf preferred over R134a?

Lower Global Warming Potential (GWP): 1234yf refrigerant has a significantly lower GWP compared to 134a, making it a more environmentally friendly option.

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