Trying Out HyChill Minus 30

I had Minus 30 in my E90’s AC system for a while. At first, it seemed to work OK. The air got cool, and I liked the idea of using a “natural” refrigerant that’s supposed to be more efficient and run at lower pressures than R134a.

But over time, I noticed a few issues:

✅ The cooling was decent, but never great — on hotter days, the system struggled more than it used to.

✅ I even started to think I might have a blend door problem, because the air was noticeably cooler on the left side of the car but came out lukewarm on the right. It really seemed like something in the HVAC system wasn’t working properly — but it turned out it was just the refrigerant not performing well enough in this car.

✅ The AC compressor developed a noticeable whine. It wasn’t there before, and it wasn’t just normal BMW AC noise — this was a clear change after switching to Minus 30.

One thing to keep in mind with HyChill is that you only need about one third of the charge compared to standard R134a. It’s possible the shop or I didn’t quite get the charge level spot on, or maybe the system just doesn’t work as well with a lower fill volume. Either way, the E90’s AC clearly didn’t like it.

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Back to R134a — and Immediate Improvement

After living with these quirks for a while, I decided to get the system evacuated and recharged with standard R134a again.

The difference was immediate:

✔️ The air is noticeably colder — it chills the cabin faster and stays cold, even in traffic on hot days.

✔️ The blend door worry vanished — the air is now equally cold on both sides of the cabin.

✔️ The compressor noise is gone. The whine disappeared as soon as the Minus 30 was out and the proper refrigerant was back in.

✔️ Overall, the system just feels like it’s working exactly as it was designed to.

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But It Works Great in My Older Triton

To be fair, I also run HyChill Minus 30 in my older 2004 Mitsubishi Triton — and in that car, it works perfectly. The AC is nice and cold, the compressor stays quiet, and I haven’t had any issues at all.

So clearly, Minus 30 can work well — it just depends on the vehicle and how its AC system was designed.

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Would I Recommend Minus 30?

I know some people swear by hydrocarbon refrigerants like HyChill Minus 30. They can be a legal and cost-effective option in some situations (always check your local laws and your car’s AC system).

Just remember — you only need about a third of the standard charge compared to R134a. If it’s not measured and charged correctly, performance can suffer.

In my experience, for my BMW E90, the standard R134a is a clear winner. For my older Triton, Minus 30 has been excellent.

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Key Takeaway

If you’re considering an alternative refrigerant like HyChill Minus 30:

• Do your homework — know what your car’s AC system was designed for.
• Make sure it’s charged properly — remember, you don’t fill it the same as R134a.
• Watch for unusual cooling patterns — like one side cold and the other side warm — that might point to refrigerant performance, not a mechanical fault.
• Listen for any new compressor noises or signs of strain.
• Sometimes “drop-in” replacements really do work well — sometimes they don’t.

For my BMW E90, I’ll be sticking with standard R134a. But for my trusty old Triton, I’m happy with Minus 30 for now.

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Have you tried Minus 30 or another hydrocarbon refrigerant? Drop a comment — I’d love to hear how it worked for you.