BMW Air-Con Regas Guide: R134a vs R1234yf and How Often London Cars Need It
A proper BMW AC service is recover, vacuum, leak-check, correct weight of the right refrigerant, and a performance test — not a 10-minute top-up in a retail park.
Which gas your BMW uses
Older cars (roughly pre-2017 depending on model) use R134a. Later cars use R1234yf. They are not interchangeable and the ports differ. We check the under-bonnet label and the VIN. Putting the wrong gas in is how compressors die.
Interval in real use
A healthy system might want a service every 3–4 years. London cars that sit and cars with stone-chipped condensers need it when the vent goes warm, not on a calendar. If it failed suddenly, treat it as a leak job — see the “not cold” article.
What we actually do
Recover remaining refrigerant legally, vacuum to boil out moisture, watch for pressure rise (a leak), then charge by weight with oil as specified. Performance test with vents and ISTA pressure. Dye if we are hunting a slow leak.
Odour and filters
Regas does not fix a mushroom smell. That is the evaporator and pollen filter. We can do both in one visit at Forest Road so you are not back a week later.
Price honesty
R1234yf is more expensive than R134a as a commodity. The quote will say which. A suspiciously cheap “any car £49 regas” is not weighing your BMW spec or testing for leaks.