Don't forget that's for my 3 litre A6, not the S8. It has a smaller/more modern air-con system. I was surprised by how little gas it needs. Old cars of mine from late 90s/early 00s have taken nearer 1kg of gas!

thats interesting, if yours is a BBA engine, the tolerance data says
R134a 530g +/- 20
oil is PAG 130 cm3 +/- 10

Engine code is ASN Neil

Just checked the sticker again - defo 550+50g R134a and 220ccm PAG oil

The German are fond of their deca (10) units so I presume there's a factor of 10 difference in whatever the Italian machine used has put back in! Slightly more oil gone back in than required, but I'm guessing that's not a problem in system pressure terms as well within the maximum gas weight.

I looked under the bonnet of the S8 and as per HPs post it's more like 750g+50 for the D2

Manufacturers are actively trying to reduce the amount of refrigerant needed in modern cars as in a front end smash the gas is invariably released into the atmosphere, which is tough to avoid as they need the front facing cooling....

Hence the newer the car, typically, the less gas it needs.....

You think they could come up with a solution that uses an intermediate heat exchanger and secondary circuit to the radiator though; some sort of heat pipe or heat pump with a different less dangerous fluid in the vulnerable area?

how strange - the tolerance data says 800 +50 now against that engine!

oil it says - Zexel compressor: VW G052 154 A2/ 250 - 300, Denso compressor: VW G052 300 A2/ 250 - 300.

http://forum.a8parts.co.uk/attachmen...1&d=1372326048

Maybe it changed during production, or is different for different markets?

Is that data predominantly USA?

The link I posted is I think USA and is consistent with your label. :cool:

One thing I don't understand about damaging atmosphere and ozone layer in particular is that R134a is heavier than air. Law pf physics. If released or leaked it will gather near soil and won't 'go up'. Perhaps I need to do some googling to understand how damage actually occurs.